Delayed feedback-based biped robot walking non-monocyclic gait control method

Abstract

The invention belongs to field of robot walking control, and in particular relates to a delayed feedback-based biped robot walking non-monocyclic gait control method which is characterized by determining a perturbation parameter p among robot walking control parameters; determining a Poincare section, a target fixed point and a nominal parameter corresponding to target fixed point; building a linearized model at a monocyclic fixed point; determining the feedback gain Kf and feedback gain Kp of a delayed feedback controller; determining the limiting value of the maximum perturbation amount; setting an original state and control parameters of a robot, solving a perturbation parameter pi of a former step, and if the perturbation parameter pi does not exceed the limit of the maximum perturbation amount, executing the perturbation parameter; if the perturbation parameter pi exceeds the limit of the maximum perturbation amount, executing the nominal parameter p*; and when a swinging leg falls to the ground, stopping the current step, and controlling a next step. According to the delayed feedback-based biped robot walking non-monocyclic gait control method, the gait can be restrained step by step through parameter perturbation by adopting only one group of constant state feedback gain, an expected fixed point can be reached fast and stably, the non-monocyclic gait is realized, and the robot walking parameter range is enlarged.

Description

[0001] Patent field [0002] The invention belongs to the field of robot walking control, and in particular relates to a non-single-cycle gait control method for biped robots based on delayed feedback. Background technique [0003] Limit cycle walking is an important type of biped robot walking mode, which has advantages in energy efficiency and speed. The limit cycle walking gait presents periodic characteristics, and the gait sequence is orbitally stable, that is, a stable limit cycle can be formed in the phase space, but it does not have local stability at any instant in the gait cycle. The coupling elastic driving method of the motor-drive rod-spring structure can realize the limit cycle walking of the biped robot on the flat ground. Since this walking mode makes full use of the dynamic characteristics of the robot itself, the artificial constraints imposed on the robot motion are relatively small. As the parameters continue to increase, the stability of the originally st...

AI Technical Summary

Problems solved by technology

[0005] The existing OGY method for controlling non-single-cycle gait has a large amount of calculation, and the feedback form depends on the state of the fixed point. If the calculation of the target fixed point is inaccurate or the parameters change unknown, it will cause the state and parameters The calculated value of the Jacobian matrix and the real value produce an error. Such an error causes the OGY method to control the non-single-cycle gait to the fixed point corresponding to another set of parameters, which deviates from the fixed point and the expected performance under the expected parameter combination. , larger errors will even cause the OGY method to fail

Another method to control non-single-cycle gait is DFC, that is, delayed feedback control, but this method has a topological limitation problem, that is, for a discrete system with an odd number of real eigenvalues ​​greater than 1 for the Jacobian matrix about the state, no matter the feedback gain No matter how to choose, the stability of the hyperbolic equilibrium point cannot be achieved.

For a model with specific parameters, the feedback gain can be determined by off-line design or heuristics. The effective single feedback gain K can usually only be selected within a narrow range, and when the parameters vary in a large range, the feedback gain K so determined Inability to ensure rapid convergence of gait, or even loss of ability to calm non-single-cycle gaits

[0006] For non-single-period gaits, when the parameters change, the embedded target single-period trajectory also changes. Using the OGY method requires repeated and accurate calculation of fixed points and linearization. The DFC method using periodic disturbances cannot guarantee convergence to The speed of a single cycle, the ability to lose composure when the parameter changes greatly

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