Sliding mode adaptive controller with built-in brushless DC motor current loop control for two-wheeled self-balancing robot

Abstract

The invention discloses a sliding mode adaptive controller with built-in brushless DC motor current loop control for a two-wheeled self-balancing robot. The controller at least comprises a sliding mode adaptive controller and a current loop active-disturbance-rejection controller, wherein the sliding mode adaptive controller is used for controlling an output motor torque T<w> according to an angle parameter Theta and an angular speed Theta-bar and converting the motor torque T<w> to a current i<*>, and the current loop active-disturbance-rejection controller is used for controlling an output voltage U<*><a0>(t) to drive a motor system to move according to the current i<*> and a motor current i detected by a sensor measurement module. With the adoption of the technical scheme disclosed by the invention, current loop control is added into the controller, thus, the size of the driving current is effectively controlled, a large current cannot be generated, the driving of a brushless motor is protected, the lifetime of a balance car is greatly prolonged, and the application safety of the balance car is greatly improved.

Description

technical field [0001] The invention relates to the field of two-wheel self-balancing robot control, in particular to a sliding-mode adaptive controller for a two-wheel self-balancing robot with a built-in brushless DC motor current loop control. Background technique [0002] The two-wheeled self-balancing robot is a self-balancing robot that uses sensors to sense its own state, and then controls the motor rotation through a control algorithm to achieve self-balancing. In recent years, with the continuous improvement of the two-wheeled self-balancing robot technology and the continuous reduction in cost, it has gradually become a means of transportation accepted by more people, making the two-wheeled self-balancing robot begin to change from the experimental research stage to a popular means of transportation. The environment and tasks are becoming more and more complex. [0003] At present, there are various types of balancing robots on the market, most of which use PID co...

AI Technical Summary

Problems solved by technology

This algorithm is simple and practical, but it is not the ideal controller, because in a complex operating environment, the algorithm does not handle it very well in many cases. For example, when there is interference from the outside world, the method will cause the control to shake When the interference is particularly large, it will also cause the balance car to lose its balance; at the same time, it is unreasonable for the PID algorithm to use the three members of proportionality, integral and differential for linear combination. Both robustness and system stability cannot be considered at the same time. Improving robustness will reduce stability, and conversely improving stability will reduce robustness

That is to say, if the robustness of the balance car using the PID algorithm is increased, it has a strong ability to keep upright, but once the angle deviation is too large, it will easily lose control, resulting in dangerous results. If the stability If it is increased, its robustness will be reduced, which will lead to a decrease in the ability of the balance car to bear the load

All in all, the robustness of the PID algorithm is not good enough, the response speed is not fast enough, the system is unstable in the face of large disturbances, and when the external road conditions change, it cannot adapt to the complex external environment and large-scale load changes. make the system chatter very large

[0004] The self-balancing robot in the prior art often causes the brushless motor to stall during actual control. In the case of stalling, a large current will be generated in the brushless motor circuit, and the MOS tube in the brushless motor drive circuit will heat up. , when the temperature is too high, the service life of the MOS tube will decrease, and if it is more serious, the MOS tube will be directly burned and the drive circuit will be short-circuited

Sometimes, due to improper operation, when the output of the brushless motor is extremely high, the rotor will be blocked, which will generate a very large surge current and directly break down the MOS tube, causing the brushless motor to run wild, resulting in a very dangerous situation.

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