Wheel type moving robot track tracking method based on fast terminal sliding mode

Abstract

The invention discloses a wheel type moving robot track tracking method based on a fast terminal sliding mode. The wheel type moving robot track tracking method comprises steps of (1) establishing a kinematic model of the wheel type moving robot and an expectation track model and establishing an error model according to the kinematic model and the expectation track model, (2) introducing an appropriate sliding mode surfaces s1, s2, designing a virtual feedback amount according to the error model <~ > theta e<->, (3) obtaining a linear speed deviation signal <~ > Upsilon and a angular velocity deviation signal <~ >Omega, (4) constructing the wheel type moving robot kinematic model and substituting the linear speed deviation signal <~ > Upsilon and the angular velocity deviation signal <~ >Omega into the kinematic model, and designing a left-and-right-wheel torque controller Tau, an unknown parameter estimator <^>Phi and an external interference disturbance estimator. The wheel type moving robot track tracking method based on a fast terminal sliding mode can track the expectation track in the limited time under the disturbance complicated working condition of the unknown parameters and the external disturbance, has a good tracking effect and has a strong robustness for the unknown parameters and the external disturbance.

Description

technical field [0001] The invention relates to a trajectory tracking method for a wheeled mobile robot, in particular to a trajectory tracking method for a wheeled mobile robot based on a fast terminal sliding mode. Background technique [0002] Wheeled mobile robots have incomparable advantages in the application of automatic material handling, special population services, emergency rescue, exploration of unknown and dangerous areas, etc., and have been widely used in the fields of industry and agriculture, service industry, national defense, and space exploration. Social production and life had a positive and far-reaching impact. For example, the "Yutu" lunar rover developed by China successfully landed on the lunar surface and collected information on the lunar surface, laying a solid foundation for China's next lunar exploration project. Motion control is the most basic and core function of the wheeled mobile robot control system. System functions such as navigation, t...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the research on the motion control of wheeled mobile robots is based on the ideal model, which does not consider the following problems: 1. In the actual model, there are nonlinear coupling items between the linear velocity and the angular velocity, and the wheel and the ground produce The friction torque and unknown external disturbance, etc.

2. Structural parameters of the actual system that cannot be accurately obtained, such as mass, inertia, wheel radius, etc. Especially in complex working environments, the structural parameters of the system may also change, and there are inevitably uncertainties and unknowns

These factors cause a large difference between the actual system and the ideal mathematical model, and the control law designed based on the ideal mathematical model is often difficult to achieve the required control performance indicators, and even cause system instability. bring greater challenges

[0004] To sum up, wheeled mobile robots will be affected by unknown external disturbances, unknown parameters, nonlinear coupling, etc. when moving under complex working conditions, which often lead to abnormal behavior of the system, leading to performance degradation or even instability of the control system. Increased the difficulty of its motion controller analysis and design

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