The inputs and outputs of the slave tractor all interfaced now. These include the inputs of GPS height, hitch height, ground speed, wheel angles and outputs for wheel steering, hitch, variable transmission and  speed control.

The tractor is now following a path in an hardware in the loop setup: The tractor is following a path with the wheels lifted from the floor. The measured inputs are used as the input for the simulator that is running a tractor simulation model.

The remote hardware controlled safety system is tested successfully on the tractor in a hardware in the loop setting. The tractor control unit software is now being prepared for running on the real-time controllers that control the machines. All necessary outputs are interfaced. Some inputs have to be interfaced via CAN. To perform a proof-of-principle test under a practical conditions, a field is rented.

At http://tyker.com/?page_id=95 a video can be found from two simulated tractors driving in master-slave configuration.

We designed the hardware controlled safety system. A systematic safety analysis was performed that consisted of several steps identification of the dangers, identification of actuator controls and actuator control values to reach a safe state. The identified actuator controls to reach a safe state for the tractor are the engine and parking brake on/off controls. The effectiveness of this measure was tested in an experiment. After the safety system has been activated the control unit could still provide controls causing dangers.  To ensure a safe state after restarting the safety system additional requirements are defined. For the hardware controlled safety system the drawings for the electronics are being made and the components are selected.

The GPS was built on the slave tractor. There was a meeting with people from tractor manufacturer Claas during which we demonstrated the results so far and clarified some technical issues regarding the tractor. The new version of the mechanical setup for lifting the slave tractor from the ground was. The slave tractor was set up at the hardware-in-the-loop test location inside a building. The test setup includes a safety fencing. 

The literature review of methods of route planning and real-time path following is finished. The algorithm for steering control and route planning are implemented. The route planning algorithm was further tested regarding its practical usability for the combination of the New Holland master tractor and a Claas Xerion tractor. Therefore the turning radii of both tractors was measured and used.

The slave tractor to be used will be a Claas Xerion and it was transported to Wageningen. A mechanical setup for lifting the tractot form the ground was implemented for future hardware in the loop simulation.