About this document......................................................................................................................................................................4
Referenced product specific documents.................................................................................................................................4
System start-up procedures....................................................................................................................................................4
Latest version of technical literature....................................................................................................................................4
Hitch positioning control concepts........................................................................................................................................... 4
Closed loop work control modes................................................................................................................................................6
Combination of position, force and slip control..............................................................................................................6
Adaptive force control...............................................................................................................................................................6
Fast down control.......................................................................................................................................................................6
In-cab control from HMI............................................................................................................................................................6
Closed loop transport modes.......................................................................................................................................................7
Rear hitch active damping.......................................................................................................................................................7
Front hitch active damping.....................................................................................................................................................7
PVBZ-HD single and double-acting actuator control..........................................................................................................9
Draft sensors for force control............................................................................................................................................. 10
Angle sensor for displacement control............................................................................................................................ 10
PLUS+1® controller power supply specification............................................................................................................10
MC024-01A controller for 10 Vdc draft sensors.............................................................................................................10
HWD for PLUS+1® controllers...............................................................................................................................................11
PLUS+1® Service Tool....................................................................................................................................................................12
PLUS+1® Service Tool functions...........................................................................................................................................12
Keyed PLUS+1® application block software and application hardware............................................................... 12
Customer access to the Hitch application block................................................................................................................ 12
Application file download and installation in GUIDE..................................................................................................12
Standard features...........................................................................................................................................................................13
Danfoss | March 202011036124 | AB152886482484en-000203 | 3
System Description
Hitch Control
Overview
About this document
This document provides general information about the PLUS+1® Hitch Control System application block.
In addition, it is a reference tool for vehicle OEM design, engineering, and service personnel.
This document is one of several sources of technical information for the hitch control system. Other
sources of technical information include individual product data sheets and application block manuals,
PLUS+1® GUIDE User Manual, and PLUS+1® Service Tool User Manual.
Referenced product specific documents
Documentation for support, development, design, and implementation of the solution.
Microcontroller
•
PLUS+1® Controller Family Technical Information, 520L0719
Basic Module Type PVBZ Valve (hitch double-acting) Data Sheet, 520L0681
•
Basic Module Type PVBZ-HS Valve (hitch single-acting) Data Sheet, 520L0956
•
Basic Module Type PVBZ-HD Valve (hitch double-acting) Data Sheet, 11035599
Software
•
PLUS+1® GUIDE Data Sheet, 520L0708
•
PLUS+1® GUIDE User Manual, 10100824
•
PLUS+1® Service Tool User Manual, 520L0899
•
Hitch Control Application Block User Manual, 11033753
System start-up procedures
•
Recommended System Start-up Procedures Technical Information, 11010667
Latest version of technical literature
Comprehensive technical literature is online at www.danfoss.com
PLUS+1® electronic controls responsibility
The manufacturer of a machine or vehicle using PLUS+1® electronic controls is responsible for correctly
applying and programming GUIDE-programmable PLUS+1® products. Danfoss strongly recommends that
the OEM perform a system-level Failure Mode Effects Analysis (FMEA).
You can find additional information about OEM responsibilities in the:
•
PLUS+1® Controller Family Technical Information, 520L0719
•
Recommended System Start-up Procedures Technical Information, 11010667
Hitch positioning control concepts
The purpose of the hitch control system is to allow the operator to position the hitch linkage either in a
work or transport position. Set points for transport and work are adjustable parameters. A closed loop
position control compares the set-point to the actual input from the position sensor. If there is a
difference, it controls the valve to lower or raise the linkage.
The goal of an automated hitch control system is to:
Danfoss | March 202011036124 | AB152886482484en-000203 | 5
Active damping
Speed scaling
ramp deadband
Valve
Danfoss
OEM supplied
OEM supplied
Danfoss Hitch Application Block
Feedback
sensors
Set-point creation and position control
Force control
Slip control
Reference setpoint
Raising and lowering speed
Human
Machine
Interface
(HMI)
3514
System Description
Hitch Control
System details
Closed loop work control modes
When the operator chooses work control mode, the position control adjusts the linkage to the depth
reference set point.
Combination of position, force and slip control
In work position it is not always possible for the tractor to do the job with the specified set point.
Therefore different sensors in the system collect information about the pull force and the wheel slip.
The system compares these inputs with an operator defined preset maximum value. If the current pull
force or wheel slip are higher than the preset maximum value, it calculates a delta and adds to the set
point for the work position.
When the set point is increased, the pull force/wheel slip decreases, and causes recalculation of the delta.
In this way, the system continually modulates the linkage position according to the sensor inputs.
Combined position, force and slip control
Adaptive force control
It is sometimes difficult for the operator to find the correct parameter settings for force control in some
work situations. Selecting adaptive force control allows the system to automatically adjust to changing
field conditions.
Fast down control
This mode gets the implement more quickly to the correct working depth.
Single acting: This mode bypasses the closed loop control and sends the valve to maximum lowering.
•
Maximum lowering is still subject to scale function according to implement weight, to avoid hazardous
lowering speeds.
Double acting: This mode maintains the closed loop control. The only difference to work mode is that
•
the digital output to switch between single and double acting, is set for double acting operation.
In-cab control from HMI
You can expand the Human Machine Interface (HMI) with up/down buttons or a joystick for manual
operation. In manual operation the operator gives direct input to the valve. This is very useful for
Analog joystick: Control of the valve is proportional from zero to the specified maximum value.
•
Digital buttons: If the application uses on/off buttons, pressing the appropriate button sets the valve
•
to the specified maximum value.
Remote operation
It is possible to operate the hitch valve with buttons outside the cab. This operation overrides any other
mode, and leaves the system in safe state after operation. When back in the cab, the operator must
choose desired mode.
In transport mode, the position control adjusts the linkage to the upper limit set point.
Rear hitch active damping
When traveling with a heavy implement lifted, the tractor can start to oscillate around the rear axle. The
result is that the front wheels no longer have a steady contact with the road. Active damping can
modulate the linkage position to offset these oscillations. Normally, the draft sensors sense these
oscillations and provide the input signal to the control.
Front hitch active damping
Active damping can benefit a front hitch as well as the rear hitch. You can add pressure sensors to the
system to provide the necessary signals to the hitch control application block.
Control for single and double acting hitch control systems are combined in one software application
block. This allows users to select the appropriate valve for the system. Options include single acting,
double acting, and switchable (between single and double acting).
PVBZ double-acting actuator control
The PVBZ meets basic market requirements for front hitches and auxiliary valves, that raise and lower
implements hydraulically. This includes the float feature.
Typical double-acting system used for front hitch
PVBZ-HS single-acting actuator control
The PVBZ-HS meets market requirements for single-acting rear hitches, that raise implements
hydraulically and lower them by gravity.
The PVBZ-HD is a more advanced alternative to the PVBZ or PVBZ-HS. This valve can operate either as
double-acting or single-acting.
The PVBZ-HD has the ability to raise, lower, press down, or float. In double-acting mode, the PVBZ-HD
increases comfort and safety when attaching and detaching heavy implements because of its ability to
raise and lower at the same speed. For field operation you may select either single or double-acting
mode.
Advanced switching between double or single-acting
Danfoss | March 202011036124 | AB152886482484en-000203 | 9
System Description
Hitch Control
Hardware components
Hitch valves
Sensors
The valve options for the Danfoss hitch control system include PVBZ double-acting, PVBZ-HS singleacting, and the PVBZ-HD single and double-acting valves. These proven PVG 32 valves feature pressure
compensation, low leakage ports (P/O-check), and optional PVLP shock/anticavitation valves. These
features are contained in PLUS+1® Compliant valve sections that incorporate ISO bus compatible PVED
electrical actuation, making them easy to integrate into the vehicle hydraulic system.
Following is a summary of typical sensors and recommended suppliers:
Draft sensors for force control
Vendor: Vishay
Sensor excitation voltage requirements must be compatible with the selected PLUS+1® microcontroller
power supply rating.
Angle sensor for displacement control
Vendor: Danfoss
Danfoss DST X510 and DST X520 series uses contactless Hall technology with measurement ranges up to
360°.
All sensors are designed for off-highway applications and resistant to shock and vibrations and with high
electromagnetic compatibility, and come with both Ratiometric, CANopen and SAE J1939 output.
Single and redundant sensor types are available and are produced according to PL d (EN ISO
13849-1:2015), making the complete portfolio suitable for safety-critical applications
Microcontrollers
Ground speed radar
Vendor: Dickey-john
The Dickey-john RVSIII series Radar Velocity Sensors utilize Doppler radar technology to output a signal
that is proportional to ground speed.
A wide range of keyed PLUS+1® microcontrollers are available, including 24 pin, 50 pin, and 88 pin
models.
PLUS+1® controller power supply specification
Normal sensor power supply output specification for Danfoss microcontrollers is 5 Vdc. Output current
rating ranges from 200 mA to 500 mA depending on the microcontroller model you select for your
application. Please refer to individual microcontroller data sheets for additional details.
MC024-01A controller for 10 Vdc draft sensors
The MC024-01A is an element of the PLUS+1® family of mobile machine management products. It is a
keyed general-purpose controller equally suited for use in a distributed machine control system, or as a
stand-alone controller.
This controller has a 10 Vdc, 0.5 A sensor supply output for use with existing hitch sensors on the market
requiring a 10 Vdc power supply.
Danfoss provides hardware description files (*.HWD file) for PLUS+1® microcontrollers. Each .HWD file
includes the operating system software for a particular microcontroller. Select a microcontroller with
input/output and power supply specifications that is suitable for your application.
Danfoss | March 202011036124 | AB152886482484en-000203 | 11
System Description
Hitch Control
Application software
Application block software description
The hitch control application block is a graphical representation of software algorithms that provide the
foundation for automated hitch control. Specific tailoring of the block is accomplished using Danfoss
PLUS+1® GUIDE tool set. GUIDE allows developers to build application software for use with Danfoss PLUS
+1® controllers. The PLUS+1® Service Tool is used to download the compiled application to the target
microcontroller.
PLUS+1® GUIDE
Customers use the hitch control application block as the starting point for a complete hitch system
application that includes input mapping, calibration, fault handling, output mapping, and connection for
HMI devices and microcontroller outputs.
The application block is released as a .SCS file, which means it can be dragged onto the GUIDE
programming workspace to be included as the application block for a complete, user-developed hitch
system application.
PLUS+1® Service Tool
The PLUS+1® Service Tool is included with the PLUS+1® GUIDE user license.
PLUS+1® Service Tool functions
Downloads software to keyed PLUS+1® hardware
•
Transfers data from the microcontroller to a PC
•
Provides interface for developing service screens for machine diagnostics, setup, and tuning
•
Keyed PLUS+1® application block software and application hardware
If the application hardware key matches the application software key 10106603 the service tool permits
the download to the target application hardware.
Customer access to the Hitch application block
The Hitch Control Application File, 70024823.ZIP
Application file contents
Software and documents enclosed in the application file include:
Hitch Control Application Block, 10108138 (*.SCS)
•
Hitch Control Application Block User Manual, 11033753 (*. PDF)
•
Hitch Control System Description, 11036124 (*.PDF)
•
Application file download and installation in GUIDE
After downloading the application file to your hard drive, you can install the application block code in the
My Blocks tab of the GUIDE component selector menu, for easy access during application development.
Software user manual and other technical information documents from the application file may be stored
in any convenient folder on your hard drive.
Single-acting and double-acting proportional valves as well as advanced multi-function valve that
•
can switch between single and double-acting
Available PLUS+1® microcontroller with a 10 Vdc sensor supply voltage suitable for general market
•
draft sensors
Wide range of standard PLUS+1® microcontrollers with 5 Vdc sensor power supply
•
Available I/O extension modules for the microcontroller to accommodate a larger number of analog
•
signals from the HMI, if needed
A generic, user-programmable application block software for controlling the hitch position
•
Other hitch control components, such as HMI controls and sensors, are typically OEM-specific, and are not
part of the Danfoss standard hitch control portfolio at this time. However, Danfoss can work with
customers to develop custom OEM-specific interface solutions.
In addition, Danfoss can assist with development of complete software solutions, tailored to specific
requirements of the OEM interface and HMI specifications, based on the application block that is
described in this document.
Benefits
Application block software is GUIDE programmable by end user: A complete software solution can be
•
created by extending the application block provided by Danfoss
Faster and easier prototyping, set-up and tuning
•
Simple logics—better user understanding
•
Single or double acting system in one software application
•
Double acting operation features enables higher safety and comfort
•
Precise control and repeatability
•
Simplified control of displacement force and slip factors
•
Safer attachment and removal of implements
•
Stable, closed-loop control in all operating modes
2800 East 13th Street
Ames, IA 50010, USA
Phone: +1 515 239 6000
Danfoss
Power Solutions Trading
(Shanghai) Co., Ltd.
Building #22, No. 1000 Jin Hai Rd
Jin Qiao, Pudong New District
Shanghai, China 201206
Phone: +86 21 2080 6201
Products we offer:
Hydro-Gear
www.hydro-gear.com
Daikin-Sauer-Danfoss
www.daikin-sauer-danfoss.com
DCV directional control
•
valves
Electric converters
•
Electric machines
•
Electric motors
•
Gear motors
•
Gear pumps
•
Hydrostatic motors
•
Hydrostatic pumps
•
Orbital motors
•
PLUS+1® controllers
•
PLUS+1® displays
•
PLUS+1® joysticks and
•
pedals
PLUS+1® operator
•
interfaces
PLUS+1® sensors
•
PLUS+1® software
•
PLUS+1® software services,
•
support and training
Position controls and
•
sensors
PVG proportional valves
•
Steering components and
•
systems
Telematics
•
Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic and
electric components. We specialize in providing state-of-the-art technology and solutions
that excel in the harsh operating conditions of the mobile off-highway market as well as the
marine sector. Building on our extensive applications expertise, we work closely with you to
ensure exceptional performance for a broad range of applications. We help you and other
customers around the world speed up system development, reduce costs and bring vehicles
and vessels to market faster.
Danfoss Power Solutions – your strongest partner in mobile hydraulics and mobile
electrification.
Go to www.danfoss.com for further product information.
We offer you expert worldwide support for ensuring the best possible solutions for
outstanding performance. And with an extensive network of Global Service Partners, we also
provide you with comprehensive global service for all of our components.
Local address:
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order provided that such alterations can be made without subsequent changes being necessary in specifications already agreed.
All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.