Precise path tracking control for farm tractors and implements became a key factor for automation m agriculture. Most recently the focus was brought on path tracking systems using steerable implements to improve overall machine productivity. For further development of those systems understanding the underlying vehicle dynamics becomes essential. This work therefore derives dynamic tractor and steerable implement models suitable for controller design and real-time simulation. In addition a path tracking controller for the overall system is presented allowing to combine steering options freely. Finally simulations are performed to analyze the use of additional steering actuators in terms of a defined control design objective. Within this work a systematic easily extensible approach to derive dynamic tractor and steerable implement models based on Lagrangian mechanics has been presented. The approach was used to model a tractor towing an implement with steerable wheels and steerable drawbar. Based on the linearized dynamic model a path tracking controller for the overall system using LQR output feedback was proposed. The controller is suitable for multiple implement steering inputs in arbitrary combinations. Finally simulations using the resulting closed loop system have been performed to demonstrate improvements achievable using the proposed controller and implements with different steering input combinations.
Dynamic modeling and path tracking control for a farm tractor towing an implement with steerable wheels and steerable drawbar
2012
10 Seiten, 5 Bilder, 1 Tabelle, 13 Quellen
Conference paper
English