Software in Tractors: Aspects of Development ... - Club of Bologna

Session: Information Technology for Agricultural Machines 

Bonn, 03. September 2006 

» Software in Tractors: 

Aspects of Development, Maintenance and Support « 

Dipl.-Ing. Rainer Hofmann, AGCO GmbH, Germany


Development of Software is like building a Cathedral …

Structure 

(1) General aspects of software engineering (in agricultural machines) 

(2) Software applications in tractors – an overview 

(3) Economical requirements for software 

(4) Software development process 

(5) Maintenance of software 

(6) Software as a product 

(7) Integration across manufactures – ISOBUS and other standards 

(8) Conclusions 

Bonn, 03. September 2006

1) General aspects of software engineering in tractors … 

• Software controls all vital functions of agricultural machines 

• Technical innovation is driven by software 


• Software is key and core competence in agricultural machinery companies 

• Manufacturers intellectual property in software engineering is a key factor 

• Quality of software defines the quality of a machine 

• Tractors and other agricultural machines are safety critical systems 

• Time, cost and quality have to be balanced 

• >> Software can be easily and quickly modified

2) Software applications in tractors 

Areas of software applications in tractors 

1. Basic (tractor) control functions 

2. Human machine interface (HMI) 

3. Automatic functions 

4. Data management 

5. Service and support 



Basic control functions (tractor tractor) 

• Engine 

• Transmission 

• Hydraulic spool valves and power lift 

• Power train (4-WD, diff.lock) 

• PTO 

• Steering 

• Brake systems 

• Electrics (lighting, washer, …) 

• HVAC 

Optimisation of mechanical functions: 

� Efficiency = ‘Load sensing’ 

� Ease of operation 

� Flexibility of production 

� Supervision to reduce wear and prevent damage 

� Diagnostic and calibration 



Human-Machine 

Human Machine-Interface Interface (HMI) 

• Dashboard 

• Graphical display systems (terminal) 

• Operator panels (armrest) 

• Multifunction levers 

• Warning and error indication 

• External or remote operation 

� Identification of driver to a machine 

� Ergonomic and intuitive operation 

� Driver focus on main or critical function 

� Simple operation / easy to learn ↔ option for manual optimisation of tractor 

functions via menu setups 



Automatic Functions 

• Engine – transmission management 

• Headland management (automatic operation sequence) 

• Automatic steering via GPS / camera / sensors 

• Implement process control 

• Precision farming process control 

� Optimisation for unskilled drivers 

� Driver focus on main or critical function 

� Intuitive and context sensitive operation of parallel processes 



Data acquisition and logging 

• Machine (load, condition, performance, position ..) 

• Agricultural working process 

• Driver and labour hours 

• (chemical) substances and material flow 

Office Software 

• Documentation / Plant Production 

• Precision Farming 

• Fleet management 

• Accounting 

Data Management 

� Legal requirements for traceability of food production 

� Economic traceability and optimisation 

� Driver is not owner of the process 



Service and Support 

• Diagnostic systems (off board) 

• Flash download and parameterize the system at 

assembly line 

• Field programming systems for software and 

parameter update 

� Reduce downtime and costs for service 

� Tracking of machine during life cycle 

� Increase flexibility in production 

� Logistic handling of software as a (‘mechanical’) part 

� Prevent manipulation e.g. speed control, engine power 


2) Software applications in tractors … 

Electronic architecture of a top end standard tractor 


2) Software applications in tractors … 

Complexity 

• Network 4 (CAN) Busses 

• 20 ECUs 

• Software per ECU 

� Multifunction armrest: 16.000 lines of code (50 files) 

� Dashboard: 28.000 lines of code (94 files) 

� Main tractor-ECU: 120.000 lines of code(230 files) 

� Vario-Terminal: 160.000 lines of code 

� Terminal with Linux OS: 50.000.000 lines of code (OS) and 

• > 90 % C-Code; 

• � 50 % Development by OEM 

• � 50% Development by suppliers 

250.000 lines of code (application) 


3) Economical requirements for software design … 

Challenges for software design 

• Low volumes of components 

• Differentiation of products 

• Short life cycles of electronic hardware components: μ-processor, memory, … 

• Long life cycle of machines in production: 10 … 15 years 

and of spare parts: 15…18 years 

• Safety critical system: hazards as machine operation and in public road traffic 

• Security against manipulation: e.g. speed control or engine power 


• Costs of hardware decrease in time compared to performance, but add to each tractor 

• Reusability of software is an economic must


Strategies and Solutions 

� Hardware independence 

� Increasing number of software modules per microprocessor 

� Integration of software modules from (different) suppliers in an (any) ECU 

� Network topology 

� Real-Time operating system 

� Generic software modules 

� Generic communication protocols 

inside microprocessor units = Virtual bus system 

and on bus networks (CAN) 

� Definite and detailed software design and verification processes 

� Software version control system 



ECU software architecture 

External bus 

system (CAN,..) 

Real-Time Operating system 

Application Software 1 

Application Software 2 

Internal virtual 

bus system (GD) 

Basic Software: 

• I/O Interface 

• Network communication management (CAN, …) 

Core Software Microcontroller 

Hardware Microcontroller 


Application Software n 

ECU


Interchangeability of software modules 

Module 

Module 

Basic Software 



External bus 

system (CAN,..) 

Module 

Module 

ECU ‚C‘ 


Module 



Module 

Module Hardware Microcontroller 




ECU ‚B‘ 

Module 

ECU ‚A‘

4) Software development process … 

V-Model: Model: design and validation cycle 

- Tractor function 

- Hardware 

- Software architecture 

- Network topology 

- Module 

- Control algorithm 

- Simulation 

Requirements 

Definition 

Basic Design 

- C-coding 

Specific Design 

- Code generation 

Component 

Implementation 

Component 

Test 

Integration Test 

(ECU) 

Vehicle Testing 

System Testing 

(HIL, Network) 


- Test bench 

- Tractor integration 

- Network integration 

- Debugger 

- Code tester 

- Simulation 

- Field test 

- Fleet test


Quality Management of Software: Design 

Requirements 

Definition 

Basic Design 

Specific Design 

Component 

Implementation 

• Risk analysis 

• Functional specification 

• FMEA 

• Software specification 

• Network and communication layout 

• Manual code generation 


• Simulation, rapid prototyping and C-code generator


Quality Management of Software: Validation 

Diversification of test methods and persons: 

• Modul level - manual and automatic test: 

� Debugger, Emulator, 

� Hardware-in-the loop: simulation and stimulation 

� Automatic code test tools 

• Integration level in tractor: 

� Validation of functionality 

� Validation of FMEA 

• Field test 

• Fleet test 

Component 

Test 

»Does a modification of 1 line of code require the full test cycle?« 

Integration Test 

(ECU) 


Vehicle Testing 

System Testing 

(HiL, Network)

5) Maintenance of software … 

Maxim of software updates 

Update of one module has to be consistent to any other module in any 

other ECU in the network of a tractor … for the whole life cycle! 


5) Maintenance of software - update process … 

Software version control for ECU update 

• Hardware - ID 

• Bootloader Flash - ID 

• Applikationssoftware - 1 - ID • Applikationssoftware - 2 – ID 

• Applikationssoftware - 2 – ID• 

… 

• … 

• Applikationssoftware - n - ID • Parametersatz - ID 

• Parametersatz - ID 



• Applikationssoftware - 1 - ID 

• Applikationssoftware - n - ID 




• Applikationssoftware - 2 – ID 

• … 








Identification of hard- and software of each ECU and each module in a tractor 

• … 







• … 


• Parametersatz - ID

5) Maintenance of software - update process … 

Software update 

• Data base contains all relevant software modules 

• ‚Label‘ is defined as a tested combination of soft- und hardware-versions 


• Update means flashing all modules and ECUs to achieve a higher or lower level 

• Update of a single ECU or module is not possible

6) Software is a product in general … 

• Modular architecture in software und communication (generic protocol) 


• Identification and registration of individual software equipment of a customer tractor 

• Commercial release process for a software update on dealer level 

• Protection against copy 

• Organisation, administration and logistic processes

7) Integration across manufacturers - ISOBUS … 

Standards, the way to handle complex electronic structures: 


… the automotive approach: … the agricultural machinery approach: 

AUTomotive Open System ARchitecture 

‘ISOBUS ISOBUS’ ISO 11783


Manufacturer .. 

Manufacturer C 

Manufacturer B 

Manufacturer A 





















Manufacturer A


An approach for further manufacturer integration 

Anwender-Plattform 

Anwender Plattform ISOBUS e.V. e.V 

• Membership for manufacturers, associations, 

suppliers, test institutes 

• Platform for electronic engineering 

• Coordination of industrial introduction of 

electronic standards 

• Development of test tools and test scenarios and 

documentation (data base) 

• Organisation and performance of workshops, 

plugfests and certification tests 

• Coordination of technical enhancements 

• Training 


8) Conclusions … 

Growing increase of … 

Functionality of software: 

• Automatic control of machines and processes 

• Field robotic 

Complexity of software: 

• Number of modules and their interdependencies 

• Integration of machine networks and data linkage to office software 

Engineering efforts and expenses: 

• … for design and development of software 

• … for test and validation of software 


• … for administration and support of software in production und service

8) Conclusions … 

… possible approaches 

• ‘Think in processes’ 

• Improve methods for absolute encapsulation of software modules 

• ‘Functional safety’: improve robustness of software 

• Extension of standards e.g. ‘ISOBUS’ (ISO 11783) 


• Establish models and platforms for software development processes between manufacturers 

• Establish economic platforms for software cooperation between OEM and suppliers 

• Open source systems – or at least open architecture

Software in Tractors: Aspects of Development ... - Club of Bologna

Create successful ePaper yourself

Delete template?

Save as template?