Mechanical control of weed is still utilized by a significant number of farmers. Accurate guidance of the tractor and cultivator is one of the precision farming challenges in mechanical weed controlling. This paper presents the control of a tractor steering system and the side motions of the attached row crop cultivator using electro-hydraulic actuators. The bicycle model was adopted to simulate the dynamic behaviour of the tractor with an implement hitched to it. It is assumed that steering angle sensor, IMU and DGPS technologies are used for measurement of the steering angle, yaw rate and the lateral position of the tractor, respectively. The lateral position data are disturbed with the DGPS noise and used to both the position control of the tractor and the side shift control of the cultivator. The cultivator control system can move the sub frame of it laterally and guide the blades near the crop rows without any crop damage. The kinematics model was used for the implement and the position was calculated through the geometric relations between the tractor and the implement. Calculation of the applying forces on the steering system of the tractor and cultivator side-shift mechanism showed that these forces are in the same range. Therefore, the MOOG servo valve series 72 and the Shore-Western servo cylinder series 910 were adopted as the hydraulic actuator for both systems. The simulations were carried out separately for each system using MATLAB. Then, these two systems were combined and the performance of the whole mechanism was evaluated through the simulation results.
