Pioneer MOBILEROBOTS User Manual

Pioneer 2
MOBILE ROBOTS
with Pioneer 2 Operating System Servers
OPERATIONS
MANUAL
Copyright © 2000, ActivMEDIA ROBOTICS, LLC
All rights reserved.
may not be copied—or in any way duplicated—without the
expressed written consent of ActivMEDIA ROBOTICS.
The software on disk and on the Pioneer 2 controller ROM, which accompany the robot
and / or are available for network download by Pioneer Mobile Robot customers,
are solely owned and copyrighted or are products of SRI International
as licensed for distribution by ActivMEDIA ROBOTICS.
Pioneer developers and users are authorized by revocable license to develop and
operate custom software for personal research and educational use only.
Duplication, distribution, reverse-engineering, or commercial
application of the Pioneer software and hardware
without the expressed written consent of
ActivMEDIA ROBOTICS is explicitly forbidden.
The various names and logos for products used in this manual are often
registered trademarks or trademarks of their respective companies.
Mention of any third-party hardware or software constitutes
neither an endorsement nor a recommendation.
ActivMEDIA ROBOTICS, LLC
44 Concord Street, Peterborough, NH 03458, USA •
www.ActivMedia.com/robots
603-924-9100 • Fax 603-924-2184
Pioneer 2 Mobile Robot—Operations Manual, v6 May, 2000
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Pioneer Mobile Robots
Table of Contents
CONGRATULATIONS.........................................................................................................................1
PIONEER PACKAGE................................................................................................................................1
Basic Components (all shipments)..................................................................................................... 1
Optional Components and Attachments (partial list)..........................................................................1
User-Supplied Components / System Requirements............................................................................2
ADDITIONAL RESOURCES.......................................................................................................................2
Pioneer Software...............................................................................................................................2
Pioneer Newsgroup........................................................................................................................... 2
Support.............................................................................................................................................3
WHAT IS PIONEER?............................................................................................................................ 4
CLIENT SOFTWARE................................................................................................................................4
THE PIONEER LEGACY...........................................................................................................................5
MODES OF OPERATION ..........................................................................................................................6
SPECIFICATIONS & CONTROLS......................................................................................................8
PHYSICAL CHARACTERISTICS................................................................................................................. 8
MAIN COMPONENTS .............................................................................................................................. 8
Console and Deck............................................................................................................................. 9
Body.................................................................................................................................................9
Nose ............................................................................................................................................... 10
Accessory Panels ............................................................................................................................ 10
Sonar Arrays................................................................................................................................... 10
MOTORS AND POSITION ENCODERS......................................................................................................10
SONARS .............................................................................................................................................. 10
BATTERIES AND POWER.......................................................................................................................11
ELECTRONICS...................................................................................................................................... 11
Power/Motor Board........................................................................................................................ 12
Microcontroller .............................................................................................................................. 12
Sonar Boards..................................................................................................................................12
CONTROLS, PORTS, AND INDICATORS................................................................................................... 12
Main Power, Fuse, and Indicator.................................................................................................... 12
Recharge/Power Port ...................................................................................................................... 12
Liquid-Crystal Display .................................................................................................................... 13
Contrast.......................................................................................................................................... 13
SERIAL........................................................................................................................................... 15
RADIO ........................................................................................................................................... 15
FLASH............................................................................................................................................ 15
SAFETY WATCHDOGS AND CONFIGURATION......................................................................................... 15
QUICK START....................................................................................................................................16
PREPARATIVE ASSEMBLY .................................................................................................................... 16
Saphira Client Installation.............................................................................................................. 16
SAPHIRA CLIENT START-UP.................................................................................................................17
PIONEER COLD START-UP.................................................................................................................... 17
RADIO ON ..................................................................................................................................... 17
STARTING SAPHIRA CLIENT/PIONEER SERVER COMMUNICATIONS......................................................... 17
A SUCCESSFUL CONNECTION............................................................................................................... 18
OPERATING THE SAPHIRA DEMO CLIENT..............................................................................................18
DISCONNECTING SERIAL COMMUNICATIONS (INTENTIONALLY OR UNINTENTIONALLY) .......................... 20
QUICKSTART TROUBLESHOOTING ........................................................................................................ 20
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JOYSTICK DRIVE AND SELF-TEST MODES................................................................................. 22
JOYSTICK DRIVE .................................................................................................................................. 22
JOYSTICK OPERATION ..........................................................................................................................22
ENGAGING SELF-TESTS........................................................................................................................22
MOTORS TEST......................................................................................................................................23
SONAR TEST ........................................................................................................................................ 23
DIGIN TEST........................................................................................................................................23
DIGOUT TEST....................................................................................................................................24
ANALOG TESTS.................................................................................................................................24
BUMPS.................................................................................................................................................24
USER PWMS........................................................................................................................................25
P2 GRIPPER..........................................................................................................................................25
COMPASS............................................................................................................................................. 25
PIONEER 2 OPERATING SYSTEM .................................................................................................. 26
COMMUNICATION PACKET PROTOCOL ..................................................................................................26
Packet Data Types...........................................................................................................................27
Packet Checksum.............................................................................................................................27
Packet Errors.................................................................................................................................. 27
SERVER INFORMATION PACKETS .......................................................................................................... 28
CLIENT COMMANDS.............................................................................................................................29
Client Command Argument Types....................................................................................................30
Saphira Client Command Support....................................................................................................31
PROGRAMMING P2OS ..........................................................................................................................31
Synchronization—SYNC .................................................................................................................. 31
Autoconfiguration............................................................................................................................ 32
Opening the Servers—OPEN............................................................................................................32
Keeping the Beat—PULSE...............................................................................................................32
Closing the Connection—CLOSE.....................................................................................................32
MOVEMENT COMMANDS......................................................................................................................32
PIONEER IN MOTION.............................................................................................................................33
Position Integration .........................................................................................................................33
SONARS...............................................................................................................................................34
INPUT / OUTPUT (I/O)...........................................................................................................................34
Digin, Timer, and ADSEL................................................................................................................34
DIGOUT and PSUPOS.................................................................................................................... 35
BUMPSTALL.....................................................................................................................................35
EXTENDED PACKETS............................................................................................................................36
Packet Processing ...........................................................................................................................36
Configuration Packets .....................................................................................................................36
Encoder Packets..............................................................................................................................36
AUX Serial Packets .........................................................................................................................36
STANDALONE MODE ............................................................................................................................ 38
UPDATING & RECONFIGURING P2OS...........................................................................................39
WHERE TO GET P2OS SOFTWARE.........................................................................................................39
INSTALLING THE P2OS UTILITIES.........................................................................................................39
UPDATING P2OS.................................................................................................................................. 39
Step 1. Serial Connection from Computer to Pioneer........................................................................ 39
Step 2: Enable FLASH .....................................................................................................................39
Step 3: Put Pioneer into Boot Mode................................................................................................. 39
Step 4: Run p2osdl........................................................................................................................... 40
Download Troubleshooting.............................................................................................................. 40
CONFIGURING P2OS OPERATING PARAMETERS.....................................................................................40
Steps 1–3: Preparing Pioneer 2 for Configuration............................................................................40
Step 4: Run p2oscf...........................................................................................................................40
Step 5: Changing the Configuration Parameters ..............................................................................40
Editing P2OS Parameters................................................................................................................41
Saving and Restoring.......................................................................................................................43
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Pioneer Mobile Robots
CALIBRATION TOOLS - REVCOUNTCAL AND COMPASSCAL.....................................................................43
MAINTENANCE & REPAIR .............................................................................................................. 45
DRIVE LUBRICATION ........................................................................................................................... 45
PIONEER BATTERIES............................................................................................................................45
Changing Batteries (DX and AT) ..................................................................................................... 45
Hot-Swapping the Batteries (DX and AT) ........................................................................................ 45
Charging the Battery....................................................................................................................... 45
Alternative Battery Chargers........................................................................................................... 45
GETTING INSIDE.................................................................................................................................. 46
Onboard Computer......................................................................................................................... 46
Top Plate........................................................................................................................................ 46
FACTORY REPAIRS .............................................................................................................................. 47
APPENDIX A (C166 CONTROLLER PORTS AND CONNECTIONS) ........................................... 48
CONSOLE SERIAL PORT ....................................................................................................................... 48
INTERNAL SERIAL CONNECTORS.......................................................................................................... 49
USER I/O EXPANSION PORT................................................................................................................. 49
THE GENERAL I/O BUS........................................................................................................................50
APPENDIX B (MOTOR-POWER BOARD CONNECTORS)...........................................................52
USER POWER CONNECTIONS................................................................................................................ 52
ONBOARD COMPUTER OPTION............................................................................................................. 53
Power Switch (J7) and Delayed Shutdown Logic ............................................................................ 53
Power-State Logic........................................................................................................................... 53
Computer Power............................................................................................................................. 53
APPENDIX C (SAPHIRA PARAMETER FILES) ............................................................................. 54
APPENDIX D (JOYSTICK CONNECTOR)....................................................................................... 56
APPENDIX E (SPECIFICATIONS) .................................................................................................... 57
INDEX..................................................................................................................................................60
WARRANTY & LIABILITIES...........................................................................................................63
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Pioneer Mobile Robots
Congratulations
on your purchase of this Pioneer 2 Mobile Robot, and welcome to the rapidly growing community of researchers, developers, and enthusiasts of Pioneer Mobile Robots .
This Pioneer 2 Operation Manual provides both the general and technical details you need to operate your Pioneer 2 Mobile Robot and to begin developing your own robotics hardware and software projects.
We encourage you to also use the companion resources that are packaged with your Pioneer Mobile Robot:
Ÿ Saphira, Ayllu, Pioneer Application Interface and P-LOGO software and manuals Ÿ Personal account for the Internet server: http://robots.activmedia.com Ÿ Pioneer-user newsgroups
Pioneer Package
Our experienced robotics-manufacturing staff put your Pioneer 2 Mobile Robot and accessories through a “burn in” period and carefully tested them before shipping the robot to you. Our care extends beyond.
In addition to the companion resources listed above, we warranty the robot and our manufactured accessories against mechanical, electronic, and labor defects for one year. Third-party accessories are warranted by their manufacturers, typically for 90 days.
All of these precautions ensure that you have many years to enjoy your new Pioneer 2 Mobile Robot. Even though we’ve made every effort to make your Pioneer package complete, please check the components again after you unpack them from the shipping crate.
Basic Components (all shipments)
Ÿ One fully assembled Pioneer 2 Mobile Robot Ÿ CD-ROM containing licensed copies of Pioneer 2 software and documentation Ÿ Hex wrenches and assorted replacement screws Ÿ Replacement fuse Ÿ Set of manuals Ÿ Registration and Account Sheet
Optional Components and Attachments (partial list)
Ÿ Battery charger (some contain power receptacle and 220VAC adapters) Ÿ Onboard PC computer with PC104+ bus, hard-drive and other accessories Ÿ Radio Ethernet and/or Modems
Ÿ One mounted inside Pioneer 2
Ÿ Companion radio for LAN or basestation connection Ÿ Supplementary and replacement batteries Ÿ 3-Battery Simultaneous Charge Station (110/220 VAC) Ÿ P2 Gripper Ÿ ActivMedia Color Trackings System Ÿ Range-Finding StereoCam System Ÿ Pan-Tilt-Zoom Surveillance System Ÿ Custom Vision System
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Congratulations
Ÿ Range-finding Laser Ÿ GPS System Ÿ Compass Ÿ Bumper Ring Ÿ Serial cables for external connections
User-Supplied Components / System Requirements
Ÿ Client computer: 486-class or later PC with Microsoft Windows 95-98/NT,
FreeBSD, or Linux operating system; Power-PC Macintosh with System 7.5 or later; or any UNIX workstation
Ÿ One RS-232-compatible serial port Ÿ Four megabytes of available hard-disk storage
Additional Resources
Every new Pioneer customer gets three additional and valuable resources:
1. A private account on our Internet server for downloading Pioneer software, updates, and manuals
2. Access to the private pioneer-users newsgroups
3. Direct access to the Pioneer technical support team
Pioneer Software
We maintain a 24-hour, seven-day per week Web server where customers can obtain Pioneer software and support materials:
http://robots.activmedia.com
Some areas of the Pioneer website are restricted to licensed customers. To gain access, enter the username and password written on the Pioneer Registration & Account Sheet that accompanied your robot.
Pioneer Newsgroup
We maintain an E-mail-based newsgroup through which Pioneer owners share ideas, software, and questions about the robot. To sign up, send an E-mail message to our automated newsgroup server:
To: pioneer-users-request@activmedia.com From: <your return e-mail address goes here> Subject: <choose one command:>
help (returns instructions) lists (returns list of newsgroups)
subscribe unsubscribe
Our SmartList-based listserver will respond automatically. After you subscribe, send your E-mail comments, suggestions, and questions intended for the worldwide community of Pioneer users:
To: pioneer-users@activmedia.com From: <your return e-mail address goes here> Subject: <something of interest to members of pioneer-users>
Access to the Pioneer-users Newslist is limited to subscribers, so your address is safe from spam. However, the list currently is unmoderated, so please confine your comments and inquiries to issues concerning the operation and programming of Pioneer.
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Pioneer Mobile Robots
Support
Have a problem? Can’t find the answer in this or any of the accompanying manuals? Or, do you know a way that we might improve Pioneer? Share your thoughts and questions directly with us:
pioneer-support@activmedia.com
Please include your robot's serial number (look for it beside the Main Power switch)we often need to understand your robot's configuration to best answer your question.
Your message goes directly to the Pioneer technical support team. There a staff member will help you or point you to a place where you can find help.
Because this is a support option, not a general-interest newsgroup like pioneer-users, we reserve the option to reply only to questions about problems with Pioneer.
(See Chapter 8, Maintenance & Repair, for more details.)
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What Is Pioneer?
Pioneer is a family of mobile robots, both two-wheel and four-wheel-drive. They are all small, intelligent robots, whose architecture was originally developed by Kurt Konolige, Ph.D., of SRI International, Inc. and Stanford University.
These are truly off-the-shelf, “plug and play” mobile robots, containing all of the basic components for sensing and navigation in a real-world environment, including battery power, drive motors and wheels, position / speed encoders, and integrated sensors and accessories. They are all managed via an onboard microcontroller and mobile-robot server software.
Your Pioneer 2 also has a variety of expansion power and I/O ports for optional, custom attachments. These include an addressable I/O bus for up to 16 devices, two RS-232 serial ports, eight digital I/O ports, five A/D ports, PSU controllers and more — all accessible through a common application interface to the robot server software, P2OS.
With the onboard computer option, Pioneer 2 has four additional RS-232 ports, a PCI bus and space for PC104+ accessory cards. With Ethernet-ready onboard autonomy, the Pioneer becomes a plug-and-play agent for multi-intelligence work.
Figure 2-1. The Basic Components of a Pioneer 2 DX
Client Software
Pioneer 2 comes with a variety of mobile robotics development software. Currently available Pioneer client software for the computing platform of your choice (UNIX, Linux, Macintosh, Win32) includes:
The Saphira client development suite with Colbert
Ayllu subsumption-like system, with multi-agent extensions
Pioneer simulator
Pioneer LOGO (P-LOGO)
Pioneer Application Interface (PAI)
Versions and all updates for supported computing platforms are available to password-registered customers for download from our software website (see Congratulations, Chapter 1):
http://robots.activmedia.com
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Pioneer Mobile Robots
Currently supported client operating systems include most UNIX, Apple Macintosh, SunOS and Solaris from Sun Microsystems, Linux, Silicon Graphics' IRIX, and Microsoft’s Win32 (32-bit) Windows.
Saphira comes with a command-line interactive language, Colbert, and a demonstration program that allows manual (keyboard or joystick) and automatic drive control of Pioneer. The program also lets you enable several built-in robotic behaviors, including collision avoidance, features recognition, and self­navigation. For details, see Quick Start, Chapter 4.
Ayllu is a tool for development of behavior-based control systems for mobile robots. It extends subsumption-style message passing to the multi-robot domain, provides for a wide variety of behavior­arbitration techniques, and allows a great deal of run-time system flexibility. This includes a dynamic reconfiguration of behavior structure and redistribution of tasks across a group of robots as determined by either task constraints or changing availability of resources. See the Ayllu Programmer’s Manual for details.
Pioneer Application Interface (PAI) is a C-language development suite that works with Saphira. It lets software developers gain closer control of the low-level details of Pioneer server. See the PAI Manual for details.
Pioneer LOGO is a version of UCB-LOGO from the University of California-Berkeley, which we’ve extended to include Pioneer commands. It provides direct, interactive control of the robot through a familiar programming language. See the P-LOGO Manual for details.
An important benefit of Pioneer’s client/server architecture is that different robot servers can be run using the same high-level client. For example, the included Pioneer simulator runs on the host machine and acts just like the robot, so that developers may conveniently perfect their application software, then run it without modification on the robot. Several clients also may share responsibility for controlling a single mobile server, which permits experimentation in distributed communication, planning, and control.
Figure 2-2. In client/server mode, Pioneer 2 requires a host computer connection.
The Pioneer Legacy
Pioneer 1 was the original design. It introduced a 68HC11-based microcontroller and the Pioneer Server Operating System (PSOS) software.
Intended mostly for indoor use on hard, flat surfaces, the Pioneer 1 has solid rubber tires and a two-wheel differential, reversible drive system with a rear caster for balance. The Pioneer 1 came standard with seven sonar range finders (two side-facing and five forward-facing) and integrated wheel encoders.
Software-wise, the Pioneer 1 initially served as a platform for SRI International's AI/fuzzy logic-based Saphira robotics applications development. But it wasn't long before it's open architecture became the popular platform for the development of a variety of alternative robotics software environments.
Many developers created software that interfaced directly with PSOS. Others extended the capabilities of Saphira (PAI and P-LOGO are two good examples), while others have implemented alternative robotics­control architectures, such as the subsumption-like Ayllu.
Functionally and programmatically identical to the Pioneer 1, the four-wheel drive, skid-steering Pioneer AT was introduced for operation in uneven indoor and outdoor environments, including loose, rough
5
terrain. Each side of the Pioneer AT is electronically and physically linked for evenly applied translational and rotational power and speeds.
Except for the drive system, there are virtually no operational differences between the Pioneer AT and the Pioneer 1: The integrated sonar arrays and microcontrollers are the same. The accessories available for the Pioneer 1 also work with the Pioneer AT. Further, applications developed for the Pioneer 1 work with little or no porting to the Pioneer AT, and vice versa.
The newest generation of Pioneer Mobile Robots—including the Pioneer 2 CE, DX, and AT models— improves upon the Pioneer 1 legacy while retaining its many important features. Indeed in most respects, particularly with applications software, Pioneer 2 works identically with Pioneer 1 models.
Sporting a more holonomic body, larger wheels and stronger motors for better indoor performance, the Pioneer 2-DX and CE models, like Pioneer 1, are two-wheel, differential-drive mobile robots. (The least expensive CE model comes with fewer options and expansion capabilities than the 2-DX.)
The four-wheel drive Pioneer 2-AT has independent motor-drivers, as well as a stall-detection systems. Unlike its predecessor, the Pioneer 2-AT comes with inflatable tires and metal wheels for much more robust operation in rough terrain, as well as the ability to carry nearly 45 kilograms (90 lbs) of payload and climb a 60-percent grade.
All Pioneer 2 models use a high-performance 20 MHz Siemens 88C166-based microcontroller, with independent motor/power and sonar-controller boards for a versatile operating environment. The controller has two RS232-standard communications ports and an expansion bus to support the many accessories available for Pioneer, as well as your own custom attachments. And the Pioneer 2 comes with high­precision (9,850 ticks-per-revolution) wheel-motor encoders for finer odometry, and translational and rotational speed controls. The Pioneer 2 also supports a full complement of sixteen sonars (eight front and eight rear) for nearly seamless object detection.
Software-wise, the Pioneer 2 is upwardly compatible with Pioneer 1: The Pioneer 2 Operating System (P2OS) software extends—but does not replace—the original PSOS. This means that even programs that interface at the lowest communication levels will work with both Pioneer 1 and with Pioneer 2 platforms. This also means that the higher level clients, such as Saphira, PAI, Ayllu, P-LOGO, and others, will work with P2OS and the host Pioneer 2 platform just as they had worked with Pioneer 1. Of course, you will have to extend your client software, as we have done with Saphira, Ayllu and others, in order to take full advantage of P2OS.
To the relief of those who have invested years in developing software for Pioneer 1, Pioneer 2 truly does combine the best of the new mobile robot technologies with the tried-and-true architecture of the original Pioneers.
Modes of Operation
You may operate Pioneer 2 in one of four modes:
Joystick Drive
Self-test
Standalone
Server Mode
The Pioneer 2 controller comes with 32K flash-programmable, read-only memory (flash-ROM) as part of its Siemens 88C166 microprocessor, and an additional 32K of dynamic RAM: 64K total memory space for your standalone robotics programs.
But we don't recommend that you start learning C166 programming. Rather, the robot comes to you installed with the latest P2OS robotics server software.
In conjunction with client software, such as Saphira, Ayllu, or PAI running on the onboard PC or a user­supplied computer, P2OS lets you take advantage of modern client /server and robot-control technologies to perform advanced robot tasks. (See Chapter 6, Pioneer 2 Operating System, for details.)
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Pioneer Mobile Robots
Most users run Pioneer in this server mode, because it gives them quick, easy access to the robotics functionality while working in high-level software on a familiar host computer.
For experiments in microcontroller-level operation of robotics functions, you may reprogram the onboard flash-ROM and RAM for direct and standalone operation of Pioneer 2. We supply the means to download, but not the microcontroller's programming software, for you to work in standalone mode.
In fact, the download utilities we provide for you to reprogram the 88C166-based controller's flash-ROM and RAM also are used to update and upgrade your P2OS. We typically provide the upgrades free for download from our website, so be sure to sign up for the pioneer-users newslist. That's where we notify our customers of the upgrades, as well as where we provide access to Pioneer users worldwide.
Finally, we provide onboard software that lets you drive the robot from a tethered joystick. And we provide some test programs that exercise Pioneer 2 microcontroller hardware and software. We examine these modes in some detail in Chapter 5, Joystick Drive and Self-Test Modes.
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Specifications and Controls
Specifications & Controls
Pioneer robots may be smaller than most, but they pack an impressive array of intelligent mobile robot capabilities that rival bigger and more expensive machines. For example, the Pioneer 2DX and CE’s modest size lends itself to navigation in tight quarters or cluttered spaces, such as classrooms, laboratories and small offices (see (Figure 3-1).
At the same time, the powerful Pioneer server, with its Saphira software client, is fully capable of mapping its environment, finding its way home and performing other sophisticated path planning.
Physical Characteristics
For a complete comparison of Pioneer 2’s physical and operational specifications, see Appendix E.
Figure 3-1. The Pioneer 2 DX/CE physical dimensions and swing radius
Weighing only 9 Kg (20 pounds with one battery), the basic Pioneer 2 Mobile Robot is lightweight, but its strong aluminum body materials, solid construction, and strut-reinforced wheels make it virtually indestructible.
These characteristics also permit Pioneer 2 to carry extraordinary payloads: The DX can carry up to 23 Kg (50 lbs.) additional weight; the Pioneer 2 AT can carry over 30 Kg (66 lbs.) more! Yet the Pioneer 2 is light-weight enough that it is also as easy to transport as a suitcasea task made even easier by the Pioneer 2's built-in handle. And because Pioneer's main components are assembled with Allen hex screws (metric sizes; tools included with robot), you have quick access to interior components and can attach accessories with a minimum of effort.
Main Components
All Pioneer 2's are composed of six main sections:
Console
Deck
Body
Nose
Sonar Arrays
Accessory Panels
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Pioneer Mobile Robots
Console and Deck
The Pioneer 2 Console and Deck are actually one piecethe top plate of the robot. The Deck is simply the flat surface for mounting projects and accessories, such as the PTZ Robotic Camera or a laser range finder. Feed-through slots behind the wheels let you conveniently route cables to the accessory panels on each side of the DX/CE or through an access panel on top of the Pioneer 2 AT. A removable plug in the middle of the Deck gives you convenient access to the interior of the robot.
In general, you should try to center the robot's load over the drive wheels. If you must add a heavy accessory to the edge of a Pioneer 2-DX or 2-CE deck, counterbalance the weight with a heavy object
on the opposite end of the deck. A full complement of batteries helps balance the robot, too.
Figure 3-2. Pioneer 2’s Console and Deck
Every Pioneer 2 has a Console that consists of a liquid-crystal display (LCD), MOTORS, and RESET control buttons and indicators, and an RS232-compatible serial port at the 9-pin DSUB connector on the front and top of the Deck.
Attached directly underneath the Console is the Pioneer 2 microcontroller. (Operational details are provided in the next chapter, Quick Start.)
Body
Pioneer 2’s sturdy, but lightweight aluminum Body houses the robot's batteries, drive motors, electronics, and other standard components, including the forward and rear sonar arrays. The Body also has sufficient room, with power and signal connectors, to support a variety of robotics accessories inside, including the Fast-Track Color Vision System, radio modems and radio Ethernet, onboard computer, and many more.
On the DX and AT models, the Pioneer 2 has a hinged rear door for easy access to the batteries. Accordingly, you may quickly hot-swap and replace any of up to three batteries.
Also at the rear of the DX and CE Body is a convenient carry handle for easy transport of the robot.
9
Specifications and Controls
Nose
The Nose of Pioneer 2 is empty, except when equipped with an onboard PC. The Nose is readily removable: Simply remove one screw from under the front sonar array, and a second screw from the bottom of the Pioneer 2, then slide the Nose away.1 This provides a quick and easy way to get at the PC104+ stack of accessory boards of the onboard PC, as well as to the sonar gain adjustment for the front sonar array (see Sonar Gain below). The Nose also is an ideal place for you to attach your own custom accessories and sensors.
Accessory Panels
The Pioneer 2 DX comes with a removeable panel on each side of the robot on which you can install accessory connnectors and controls. A special sidepanel comes with the onboard PC option, for example, which gives users monitor, keyboard, mouse (serial port), and 10base-T Ethernet access, as well as the means to reset and power the computer.
The AT comes with a single accessory panel in the Deck. Fastened down with finger-tight screws, the AT accessory panel is accessible through its hinged door.
Sonar Arrays
Pioneer 2 supports up to two sonar range-finding arrays. One array, affixed under the front of the Deck and atop the Nose, provides forward- and side-range sensing. The other, an optional sonar array is attached just beneath the rear Deck and provides rearward, as well as side sensing. All arrays contain eight sonars, for a total of 16 sonars around the robot.
Motors and Position Encoders
Pioneer 2’s drive system uses high-speed, high-torque, reversible-DC motors. Each front drive motor includes a high-resolution optical quadrature shaft encoder that provides 9,850 ticks per wheel revolution (19 ticks per millimeter) for precise position and speed sensing and advanced dead-reckoning.
Sonars
Natively, the Pioneer 2 AT and DX support both front and rear sonar arrays (CE front only), each with eight transducers that provide object detection and range information for features recognition, as well as navigation around obstacles. The sonar positions are fixed in both arrays: one on each side, and six facing outward at 20-degree intervals, together providing 360 degrees of nearly seamless sensing. An additional 16 sonars in two banks also are available with accessory hardware.
Figure 3-3. Pioneer 2 sonar array
1
When attached, you will need to first remove the P2 Gripper before removing the Nose.
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Pioneer Mobile Robots
The sonar firing rate is 25 Hz (40 milliseconds per sonar per array) and sensitivity ranges from ten cm (six inches) to more than five meters (16 feet). (Objects closer than ten cm are not detected.) You may control the sonar’s firing pattern through software; the default is left-to-right in sequence for the forward array (Figure 3-3) and right-to-left on the rear. One sonar from each array "ping" simultaneously.
The driver electronics for the forward and rear sonar sensor arrays each are calibrated at the factory. However, you may adjust their sensitivity and range to accommodate differing Pioneer 2 operating environments. The sonar gain control is on the underside of the sonar driver board, which is attached to the floor of each sonar module.
Both banks’ sensitivity adjusment controls are accessible directly, although you will need to remove the P2 Gripper to access the front sonar, if you have that accessory attached. For the font sonar, for instance, from the underside, locate a hole near the front of the sonar module through which you can see the cap of the sonar-gain adjustment potentiometer. Using a flat-blade screwdriver, turn the gain control counterclockwise to make the sonar less sensitive to external noise and false echoes.
Low sonar-gain settings reduce the robot’s ability to see small objects. Under some circumstances, that is desirable. For instance, attenuate the sonar if you are operating in a noisy environment or on uneven or highly reflective floora heavy shag carpet, for example. If the sonars are too sensitive, they will “see” the carpet immediately ahead of the robot as an obstacle.
Increase the sensitivity of the sonar array by turning the gain-adjustment screw clockwise, making the sonar more likely to see small objects or objects at a greater distance. For instance, increase the sonar gain if you are operating in a relatively quiet and open environment with a smooth floor surface.
Batteries and Power
The Pioneer 2 CE has a single, twelve-volt, direct-current, seven ampere-hour (84 watt-hour) sealed lead/acid battery which supplies ample power for its drives, electronics, and accessories. Typical intermittent operation of the motors gives six or more hours of Pioneer 2-CE use.
The Pioneer 2 DX and AT models may contain up to three, hot-swappable, seven ampere-hour, 12 VDC sealed lead/acid batteries (total of 252 watt-hours), accessible though a hinged and latched back door.
Similar to the CE model, the battery life of the Pioneer 2 DX and AT, of course, depends on the configuration of accessories and motor activity. Pioneer 2-AT charge life typically ranges from four to eight hours. Pioneer 2-DX can run for more than a day.
If you don’t use the motors, Pioneer 2’s native electronics will run for several days on a single battery charge.
Balance the batteries in your Pioneer 2.
IMPORTANT: Batteries have a significant impact on the balance and operation of your robot. For the Pioneer 2-DX and 2-AT, under most conditions, we recommend operating with three batteries. Otherwise, a single battery should be mounted in the center, or two batteries inserted on each side of the battery container.
Typical recharge time using the recommended accessory recharger varies according to the battery’s discharge state; it is roughly equal to three hours per volt. The optional Charge Cube allows simultaneous recharge of three swappable batteries outside the robot.
With the optional high-speed Charger, recharge time is greatly reduced, but caare must be taken not to overcharge and thereby damage batteries.
Electronics
The Pioneer 2’s standard electronics reside on three main boards: The microcontroller is mounted under the Console Deck; a power / motor controller board is mounted to the battery box inside the robot; and a sonar controller (one for each array) is mounted in the base of the sonar array.
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Specifications and Controls
A Main Power switch at the back of the robot controls power for the entire system. Processor control switches and indicators fit through the Deck Console.
Power/Motor Board
Inside the robot, mounted to the battery box, is the Pioneer 2 Motor-Power board. It supplies both the twelve and five VDC power requirements of Pioneer 2's standard systems. Additionally, it has user­accessible five and 12 VDC connectors, which supply 1–2.5 amperes of power for accessories, depending on configuration. The Motor-Power board also contains the motor-driver electronics, as controlled by the microcontroller.
The standard Motor-Power board has a 12-pin user-power connector that supports four sets of five- and 12 VDC power ports (total one ampere) for custom accessories. An optional computer-power section to the board supplies up to seven amperes at five VDC power for an onboard PC. The power board includes special low-power and power-down circuit that lets you gently shut down the computer without direct connection through a keyboard or monitor. (See Appendix B in this manual and the Computer Tech Notes pamphlet that accompany the Pioneer 2 for details.)
Microcontroller
Pioneer 2's microcontroller uses a 20 MHz Siemens 88C166 microprocessor with integrated 32K flash­ROM. The microcontroller also has 32K of dynamic RAM, two RS232-compatible serial ports, several digital and analog-to-digital, and PSU I/O user-accessible ports, and an eight-bit expansion bus. See Appendix A for port details.)
All the I/O ports, except those used for the motors, encoders, and sonar, are available to the user for Pioneer 2 accessory hardware, which you may control through the P2OS. Port connector pinouts and electronic details appear in the Appendices.
Sonar Boards
Associated with each sonar arrayforward and rearis a sonar multiplexer / firing board. Wire leads to the individual sonar plug into a 16-pin connector on the board. A 10-conductor signal cable connects the sonar board with the microcontroller.
Controls, Ports, and Indicators
Main Power, Fuse, and Indicator
A single slide-switch on the rear left panel of the Pioneer 2 DX, AT and CE models controls power to the entire robot and all its integrated accessories. Up is ON; down is OFF. A red LED on the Console indicates Main Power.
Inside, on the top right side of the battery box (accessible through the hinged back door of the Pioneer 2 DX and AT) is the Main Power Fuse. It is an automotive-type (spade terminals) 15A (DX, CE) or 30A (AT) fuse designed for tool-less replacement. To the left of the fuse, on the same board, is the main power relay, which isolates the high-ampere draw of the robot system from the Main Power Switch.
Recharge/Power Port
Below the Main Power Switch is the battery Recharger port. It provides 12 VDC power to the robot's electronics, motors, and accessories, even without batteries. Use the recommended accessory power charger or equivalent.
You should maintain Pioneer 2’s batteries in a charged state above 11 VDC, as indicated on the robot’s LCD. We recommend recharging the battery when it falls below 11 VDC, even though the robot may continue to operate below 10 VDC. The microcontroller will sound a warning when the battery voltage falls below that set level (see Chapter 7, Updating and Reconfiguring P2OS), and the optional computer
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Pioneer Mobile Robots
power circuitry will automatically shut down the onboard PC. Discharging the batteries to below 10 VDC damages them.
Disengage the motors when recharging the robot.
You may continue to operate Pioneer while charging its batteries, although that will lengthen the recharge time.
If you have only one battery onboard, plug Pioneer into the charger to “hot-swap” the exhausted battery for a fresh one. To hot-swap two or three batteries, exchange each exhausted battery one-at-a-time for a fresh one, leaving at least one battery in place to supply power to the robot.
The Pioneer 2 chargers also may be used with the Pioneer 2 Charge Cube accessory.
Liquid-Crystal Display
When powered on, information about the robot's state and connections appears on a 16-character by two­line liquid-crystal display (LCD) on the left side of Pioneer 2’s Console.
When under control of the P2OS server, for example, the display shows the state of communication with the client computer, along with the battery voltage and a blinking "heartbeat" asterisk (*) as the last six characters in the second line of text.
Contrast
A small, contrast-adjustment potentiometer for the LCD is inset next to the display. Make sure the Main Power switch is on and the battery is well charged. Then, using a small, flat-blade screwdriver, turn the adjustment screw to darken or lighten the screen so that the characters are clearly visible under your lighting conditions.
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Specifications and Controls
Figure 3-3. Pioneer 2 Console
RESET and MOTORS
The RESET (red) and MOTORS (white) push-button switches on the Pioneer 2 Console affect the microcontroller’s logic and motor driver systems. Both are under software control.
When pressed alone, RESET puts the microcontroller into its start-up state, disrupting any running program or client connection. It also disables the drive motors—just as if you cycle Main Power. But, unlike a cold­power restart, RESET preserves the contents of the Pioneer 2 microcontroller's RAM, so any user programs downloaded in standalone mode get restarted.
The MOTORS pushbutton is NOT a power switch—it does not directly control
power to the motors. P2OS does and your standalone software must.
The MOTORS button and its associated green LED are under software control. Normally, Pioneer 2's motors are disabled when not connected to a client, or when not running in joystick-drive or self-test mode, when running a standalone program on the controller.
Pressing and releasing the white MOTORS button enables/disables the motors when connected with a P2OS client. When first connected with a client, the motors remain disabled (LED flashes) until you press and release the MOTORS button. The green LED should light continuously when the motors are enabled and blink on / off when disengaged.
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Pioneer Mobile Robots
Under P2OS control when not connected with a client, pressing and releasing the MOTORS button puts Pioneer 2 into joystick-drive mode. A subsequent press/release puts it into self-test mode that exercises the robot's drive, controller, and I/O systems. (See Chapter 5, Joystick andSelf-Test Modes, for details.)
Pressing and holding the MOTORS button in combination with pressing and releasing the RESET button puts the microcontroller board into a special download mode for reprogramming the onboard flash PROM and RAM. See Pioneering 2 Operating System and Updating & Reconfiguring P2OS, Chapters 6 and 7.
SERIAL
Pioneer 2's microcontroller has two serial ports and three connectors. One connector, a standard 9-pin D­SUB receptacle, is located on the Console and is for direct RS232-compatible serial data communication between the microcontroller and an client computer. SERIAL shares its three-line transmit, receive, and ground connections with one of the two serial ports that are inside the robot. (See Appendix A for pinouts and cabling connections.)
Two amber LEDs on either side of the Serial Port flash during actual data activity transmitted from or received by the microcontroller.
Remove any tether or laptop connection from the Console SERIAL port
when using the optional radio modems.
RADIO
The RADIO slide switch on Pioneer 2's Console controls power to the optional radio modem or Ethernet radio. The RADIO switch does not affect the SERIAL port functions directly, but you must switch a radio modem’s power off if you use the Console Serial Port to connect a piggyback laptop or another external computer to the robot. (The radio modem gets connected to the microcontroller via the internal, shared serial port.)
FLASH
A slide switch labeled FLASH is recessed into the Console. It write-protects the flash PROM-stored P2OS software and your Pioneer 2's operating parameters (see Updating and Reconfiguring P2OS, Chapter 7). When switched forward, toward the front of the robot, FLASH is enabled for writing. (The P2OS utilities that accompany your robot will warn you if FLASH is disabled.)
Safety Watchdogs and Configuration
Pioneer’s standard onboard software, P2OS, contains a communications watchdog that will halt motion if communications between a client computer and the server are disrupted for a set time interval, nominally two seconds (watchdog). The robot will automatically resume activity, including motion, as soon as communications are restored.
Also, Pioneer’s server software contains a stall monitor. If the drive exerts a PWM pulse that equals or exceeds a configurable level and the wheels fail to turn (stallval), motor power is cut off for a configurable amount of time (stallwait). The server software also notifies the client which side is stalled. When the time elapses, motor power automatically switches back on and motion continues under server control.
Both these “failsafe” mechanisms help ensure that the robot will not damage objects or be electrically damaged during operation. You may reconfigure the communications, drive current, and stall-wait values to suit your Pioneer’s application. (See Chapter 7, Updating & Reconfiguring P2OS, for details.)
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