CN-122014805-A - Hydraulic mechanical leg vibration reduction control method based on rotary magnetorheological damping knee joint

CN122014805ACN 122014805 ACN122014805 ACN 122014805ACN-122014805-A

Abstract

The invention relates to a hydraulic mechanical leg vibration reduction control method based on a rotary magnetorheological damping knee joint, which comprises the steps of inputting an error of a displacement signal of a hydraulic actuator to a hydraulic PID controller, controlling the hydraulic actuator to drive a mechanical leg to act, establishing a mechanical leg dynamics model, obtaining a load force on the hydraulic actuator through conversion of moment and force of the mechanical leg, establishing a hydraulic actuator driving load balance equation, establishing a stable system motion state discriminant, combining the driving load balance equation and the system motion state discriminant, obtaining an expected output damping moment and a damper output force which take the force balance of the hydraulic actuator and the system motion error as ideal targets, inputting the expected output damping moment to the controller, enabling the output damping force to act on the hydraulic actuator, and realizing vibration suppression. The invention gives consideration to the balance of the driving load of the system and the high-precision motion control, and can realize accurate and efficient vibration reduction of the hydraulic mechanical leg.

Inventors

HUANG HUI
HUANG JIABO
LIN XIUFANG
DU HENG
LI YUZHENG
LAN JINHUA

Assignees

福州大学

Dates

Publication Date: 20260512
Application Date: 20260213

Claims (6)

1. The hydraulic mechanical leg vibration reduction control method based on the rotary magnetorheological damping knee joint is characterized in that the mechanical leg comprises a thigh structure, a knee joint and a shank structure which are sequentially connected, the knee joint adopts a rotary magnetorheological damper, the lower end of the thigh structure is connected with a rotating shaft of the rotary magnetorheological damper, the rear end of the thigh structure is provided with a hydraulic actuator, the telescopic end of the hydraulic actuator is connected with the rotary input end of the rotary magnetorheological damper, the upper end of the shank structure is connected with the rotary output end of the rotary magnetorheological damper, the hydraulic actuator is controlled by a hydraulic PID controller, the rotary magnetorheological damper is controlled by a damper PID controller to output damping force, and the vibration reduction control method comprises the following steps: Step S1, inputting an error of a displacement signal of a hydraulic actuator in a mechanical leg to a hydraulic PID controller, and driving the mechanical leg to act by controlling the hydraulic actuator; Step S2, establishing a mechanical leg dynamic model, obtaining moment generated by movement of the mechanical leg, and obtaining a load force F L on the hydraulic actuator through conversion of the moment and the force; Step S3, establishing a driving load balance equation of the hydraulic actuator; S4, establishing a system motion state discriminant based on a system stable state; Step S5, combining the hydraulic actuator driving load balance equation established in the step S3 with the system motion state discriminant established in the step S4 to obtain the expected output damping moment M and the damper output force F M of the rotary magnetorheological damper taking the force balance of the hydraulic actuator and the system motion error as an ideal target; And S6, inputting expected output damping moment M 0 of the damper to a PID controller of the damper so as to output a signal to a nonlinear controller, outputting a current signal I 0 to a motion state compensator after nonlinear control, and finally outputting a control current I to the rotary magnetorheological damper, so that the output damping force F M of the rotary magnetorheological damper acts on the hydraulic actuator, and vibration is restrained.
2. The hydraulic mechanical leg vibration damping control method based on the rotary magnetorheological damping knee joint according to claim 1, wherein the hydraulic actuator driving load balance equation established in the step S3 is expressed as follows: Wherein A is the working area of a piston of the hydraulic actuator, p 1 、p 2 is the pressure of a left cavity and a right cavity of the hydraulic actuator respectively, m is the total mass of the piston of the hydraulic actuator and the external load calculated on the piston of the hydraulic actuator, B p is the viscous damping coefficient, K is the load elastic rigidity, p The displacement is fed back for the piston rod of the hydraulic actuator, Indicating the external force acting on the piston, The force output by the magneto-rheological damper.
3. The method for controlling vibration damping of a hydraulic mechanical leg based on a rotary magnetorheological damping knee joint according to claim 1, wherein in the system motion state discriminant established in the step S4, in order to make the system motion error be 0, a piston rod of the hydraulic actuator should satisfy: Wherein W is a weight matrix, Wherein E is the error matrix of the error matrix, ; Wherein k 1 、k 2 is constant and k 1 >0,k 2 >0; 、、 The displacement error, the speed error and the acceleration error of the piston rod of the hydraulic actuator are respectively.
4. The hydraulic mechanical leg vibration damping control method based on the rotary magnetorheological damping knee joint according to claim 3, wherein the expressions of the piston rod displacement error, the speed error and the acceleration error of the hydraulic actuator are respectively as follows: ; ; ; Wherein, the 、、 The displacement, the speed and the acceleration of the piston rod of the hydraulic actuator are respectively expected.
5. The method for controlling vibration damping of a hydraulic mechanical leg based on a rotary magnetorheological damping knee joint according to claim 1, wherein in step S5, the expected output damping force F M0 of the rotary magnetorheological damper taking the force balance of the hydraulic actuator and the system motion error of 0 as an ideal target is expressed as: 。
6. The method for damping control of a hydraulic mechanical leg based on a rotary magnetorheological damping knee joint according to claim 1, wherein in step S6, the rule of the motion state compensator is that a piston rod displacement error of the hydraulic actuator Error in speed of piston rod of hydraulic actuator At the same time, namely the hydraulic mechanical leg is far away from the balance state, the current signal I=I 0 is output, and the displacement error of the piston rod of the hydraulic actuator Error in speed of piston rod of hydraulic actuator When the number is different, that is, the hydraulic mechanical leg is approaching the equilibrium state, the current signal i=0 is output.

Description

Hydraulic mechanical leg vibration reduction control method based on rotary magnetorheological damping knee joint Technical Field The invention belongs to the technical field of mechanical leg vibration reduction control, and particularly relates to a hydraulic mechanical leg vibration reduction control method based on a rotary magnetorheological damping knee joint. Background The 21 st century has completed the transformation from the field of industrial application to the fields of medical service, education entertainment, survey rescue and the like, becomes an important sign for measuring the scientific research level of a country, and has higher power density and stronger terrain adaptability, and potential application prospects in environmental detection and military transportation under unstructured terrains. The hydraulic valve control cylinder system is used as a power actuator of the foot robot, and the telescopic movement of the piston rod is mainly converted into the complex gait of the mechanical leg through the leg connecting rod mechanism. However, the inherent under-damping characteristic of the hydraulic valve-controlled cylinder system is always a challenge problem in the hydraulic system, and the vibration generated by the hydraulic valve-controlled cylinder system can cause low precision and poor controllability of hydraulic equipment, so that the foot-type robot generates larger contact collision force or foot-end vibration phenomenon when the foot-type robot interacts or performs complex actions. Therefore, the vibration reduction and impact resistance of the hydraulic foot robot are improved, and the hydraulic foot robot has important significance for improving the motion stability and prolonging the service life. In recent years, the magnetorheological fluid gradually enters the field of vision of people as a novel intelligent material, has a special magnetorheological effect, can change the apparent viscosity of the magnetorheological fluid along with the size of an externally applied magnetic field, and provides a brand new thought for vibration control of a mechanical system. The magnetorheological damper manufactured based on the method is relatively simple in structure, excellent in performance, safe and reliable in work, low in energy consumption, high in response speed and capable of being continuously and adjustably controlled in real time, and the output of the magnetorheological damper can be controlled by controlling the input current. At present, the vibration suppression and control thought of the hydraulic mechanical leg provide solutions to a certain extent, but the problems and limitations still exist. The traditional scheme has the defects of fixed damping, incapability of quick response and the like on the vibration reduction scheme, and the control effect is poor due to inaccurate damper control force and control current on the magnetorheological damper control method, and mainly has the following aspects: 1. The hydraulic mechanical leg vibration damping control scheme is aimed at. The existing research directions include hybrid vibration damping control of a hydraulic system and an electric drive system, passive control of hydraulic mechanical legs by damping generated by using a fixed damping vibration damper, and improvement of dynamic response capability of the hydraulic system by optimizing a fluid channel, a valve design, a fluid flow path and the like in the hydraulic system, so that vibration damping effect is enhanced. The problems of complex system, non-adjustable damping, poor control adaptability and the like of the solutions are solved, and the device has the advantages of compact structure and low energy consumption by designing and popularizing the flexible joint capable of realizing variable stiffness and variable damping in the flexible robot by combining the damping characteristic of the magnetorheological damper and the variable stiffness characteristic of the spring in the flexible joint research of the rotary magnetorheological robot with variable stiffness and damping in paper. However, the method has the defects that the damping rigidity cannot be adjusted in real time, the vibration cannot be directly responded quickly, and the like. 2. The control method aspect of the magneto-rheological damper is aimed at. The existing control method mainly comprises self-adaptive control, state space-based control, optimization algorithm-based control and the like. Aiming at the hydraulic mechanical leg vibration reduction based on the magneto-rheological damper, most of the prior methods rely on single vibration or impact signals for calculation for the vibration reduction core design, such as vibration sensor feedback signals, hydraulic actuator displacement, speed, load force and the like, neglect the whole driving load balance of the hydraulic mechanical leg system and the control precision requirement in the motion process, and result in that althoug