Trajectory Tracking Based on Adaptive Sliding Mode Control for Agricultural Tractor

Abstract

Trajectory tracking is one of the key technologies for high-precision agriculture and has been the research focus by a large number of academics. In order to design a simple trajectory tracking control scheme, an adaptive sliding mode control based on lateral deviation is proposed. To reduce the chattering phenomenon, an adjustable parameter associated with the sliding surface and system error is introduced, by which the forward gain value can be regulated with the state change. According to the established tractor model, the desired front wheel angle can be obtained as the output of the sliding mode controller. A modified Smith predictor structure based two degree of freedom control scheme is designed to follow the desired front wheel angle. The effectiveness of the designed trajectory tracking control system is demonstrated by simulations, especially the performance of preventing chattering phenomenon.

Trajectory tracking for agricultural tractor based on improved fuzzy sliding mode control

“…What’s more, the fact that tractor changes speed while driving is taken into consideration. Therefore, a three DOF model is developed based on the literature [ 37 ], with the heading angle, lateral displacement, and longitudinal velocity as shown in Fig 3 .…”

Coupled Lateral and Longitudinal Controller for Over-Actuated Vehicle in Evasive Maneuvering With Sliding Mode Control Strategy

“…in which ∆y is the distance between the vehicle's CoG and the reference path in the perpendicular direction Y of the vehicle coordinate system (see Figure 3); ∆ ẏ is the relative lateral velocity between CoG and the reference path; k yd , k yv ,k r ∈ R [59] are the gradient coefficients that can be adjusted as a function of state and time respectively. ∆r is the difference between the actual and desired yaw rate r d .…”

LQR-MPC-Based Trajectory-Tracking Controller of Autonomous Vehicle Subject to Coupling Effects and Driving State Uncertainties

“…In the past few years, numerous control techniques have been studied to address the problem of trajectory tracking in autonomous vehicles. The existing control methods, such as sliding mode control (SMC) [ 3 , 4 , 5 ], robust control [ 6 ], model predictive control (MPC) [ 7 , 8 , 9 , 10 , 11 , 12 ], the linear quadratic regulator (LQR) [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], and the classic PID control [ 8 , 19 ], were proposed to pursue the task of lateral and longitudinal control. However, most of these studies aimed to address the lateral and longitudinal control separately.…”

“…However, the SMC technique usually results in chattering phenomenon while obtaining robustness. To cope with this drawback, the authors of [ 3 ] proposed an adaptive SMC approach based on lateral deviation, where an adjustable parameter related to the sliding surface and system error was introduced to reduce the chatter. However, the existence of system inertia will cause the switching delay of the SMC system, which is negative for vehicle’s lateral control.…”