A Parameter Calibration Method for Pneumatic Artificial Muscle Actuator

Abstract

The invention relates to a parameter calibrating method for a pneumatic artificial muscle (PAM) actuator. The parameter calibrating method comprises the following steps: (1), measuring the maximum output force of the PAM under n atmospheric pressures pi, marking the maximum output force as fmax,i, and solving the initial value theta0 of a knitting angle based on the fact that the slope of a fmax,i-pi fitting straight line conforms to the slope of a theoretical model fmax,i = f(0, pi, theta); (2), using the theoretical model to solve initial zero-output-force deformation lambda0 caused by fiber relaxation, and deducting maximum output force fmax,i<1> under the condition of zero initial deformation; (3), calibrating a fiber angle theta by using the slope of a fmax,i<1>-pi fitting curved line; and (4), as the knitting angle theta is regulated, calculating lambda0 again according to the step (2), calculating theta again according to the step (3), carrying out iteration in this way, and when differences between the fmax,i<1> obtained by calculation in the step (2) of an iteration and all fmax,i<1> in the step (2) of previous iteration meet set threshold values, obtaining the initial deformation lambda0 and the knitting angle theta of the PAM. Compared with the prior art, the parameter calibrating method solves the problems of fiber relaxation, assembling clearances and fiber knitting angle errors in the PAM.

Description

technical field

[0001] The invention relates to a pneumatic artificial muscle (Pneumatic artificial muscle, PAM) actuator, in particular to a parameter calibration method for a pneumatic artificial muscle actuator. Background technique

[0002] It is generally difficult to fit perfectly between the silicone tube and the fiber sleeve, and there is a certain gap between the silicone tube and the pneumatic interface when assembling. After inflating, the silicone tube expands to a certain extent first, and the pneumatic force is transmitted to the fiber sleeve after various gaps disappear. The air pressure is mainly used to overcome the elastic deformation of the silicone tube. Therefore, on the air pressure-maximum output force relationship curve (straight line), it can be observed that the air pressure is not zero, but the maximum output force is zero, which is inconsistent with the theoretical model and can be called "dead zone". The usual practice is to obtain the air press...

Examples

Embodiment Construction

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0020] The output force f of the contracted PAM actuator after pressurization is usually related to the shrinkage ratio λ, the internal and external pressure difference p, the fiber weaving angle θ and other PAM material properties. Regardless of the influence of its own material properties, f is the first three parameters. function, namely

[0021] f=f(λ,p,θ)

[0022] where λ=(L 0 -l) / L 0 , l is the length of the pneumatic artificial muscle at a certai...

technical field

[0001] The invention relates to a pneumatic artificial muscle (Pneumatic artificial muscle, PAM) actuator, in particular to a parameter calibration method for a pneumatic artificial muscle actuator. Background technique

[0002] It is generally difficult to fit perfectly between the silicone tube and the fiber sleeve, and there is a certain gap between the silicone tube and the pneumatic interface when assembling. After inflating, the silicone tube expands to a certain extent first, and the pneumatic force is transmitted to the fiber sleeve after various gaps disappear. The air pressure is mainly used to overcome the elastic deformation of the silicone tube. Therefore, on the air pressure-maximum output force relationship curve (straight line), it can be observed that the air pressure is not zero, but the maximum output force is zero, which is inconsistent with the theoretical model and can be called "dead zone". The usual practice is to obtain the air press...

Examples

Embodiment Construction

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0020] The output force f of the contracted PAM actuator after pressurization is usually related to the shrinkage ratio λ, the internal and external pressure difference p, the fiber weaving angle θ and other PAM material properties. Regardless of the influence of its own material properties, f is the first three parameters. function, namely

[0021] f=f(λ,p,θ)

[0022] where λ=(L 0 -l) / L 0 , l is the length of the pneumatic artificial muscle at a certai...

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