CN110253584A - A Discrete Time Variable Boundary Bilateral Control Method for Remote Control - Google Patents

Abstract

The invention belongs to Manipulator Dynamics fields, it is related to a kind of discrete time variable boundary bilateral control method towards remote control, establish discrete time remote control bilateral control system, for scheduled state boundaries, the value tag of bonding state deviation, the switching signal of design control law, discrete time bilateral control rule.The present invention realizes that the direct application of the bilateral control method of state bounded in computer systems also ensures the lasting accuracy of system by the Rational choice of parameter while guaranteeing bilateral synchronous.

Description

A Discrete Time Variable Boundary Bilateral Control Method for Remote Control

technical field

The invention belongs to the field of mechanical arm dynamics, and relates to a remote control-oriented discrete time variable boundary bilateral control method.

Background technique

Remote control technology can support robots to realize the migration of human behavior in time and space in dangerous or cross-domain situations that are difficult for humans to get involved in, such as taking over and manipulating mission targets in underwater, toxic, nuclear and space environments. . Considering the synchronization problem of master and slave operations in remote control, it is necessary to design a high-synchronization finite state control method. On the one hand, it can improve the synchronization accuracy of remote control, and on the other hand, it can ensure the reliability of slave operation. The currently commonly used methods involve bounded states, but there is no discrete-time method suitable for actual physical systems, which cannot effectively resolve the influence of sampling time on the control effect, and then reduces the bilateral control accuracy.

Contents of the invention

technical problem to be solved

In order to avoid the deficiencies of the prior art, the present invention proposes a remote control-oriented discrete time variable boundary bilateral control method, using this method to realize the direct application of the state bounded bilateral control method in the computer system, ensuring bilateral synchronization while , the reasonable selection of parameters can also ensure the stability and accuracy of the system.

Technical solutions

A discrete time variable boundary bilateral control method oriented to remote control, characterized in that the steps are as follows:

Step 1: Discrete time remote control bilateral control system:

Among them, the subscripts m and s refer to the remote-controlled master and slave manipulators respectively. For the convenience of description, i=m, s are used to describe the subsequent variables, and k represents the sampling time. represents the joint intersection vector, represents the positive definite inertia matrix, represents the Coriolis force matrix, is an unknown but bounded external disturbance, represents the input force of the human operator, represents the environmental force, Indicates the torque output by the mechanical arm;

Convert the bilateral control model to obtain the following differential expression:

q _i (k+1)=q _i (k)+δΔq _i (k)

Δq _i (k+1)=Δq _i (k)+δf _i (k)+δg _i (k)u _i (k)+δd _i (k)

where δ represents the sampling interval of the discrete-time system, corresponding to the bilateral control model, and obtains:

d _i (k)=-B _i (Δq _i (k))

Among them, F _i (k) corresponds to the environmental force and the input of the operator according to the situation;

Step 2: For the predetermined state boundary, combined with the value characteristics of the state deviation, design the switching signal of the control law:

Synchronization error:

Among them, the error of the master end is e _m (k), the error of the slave end is e _s (k), and T _m and T _s respectively represent the delay time of the master end and the slave end relative to the multiplier of the sampling interval. The joint angle limit of the bilateral manipulator is Where q _ij (k) represents the angular position of the jth joint angle of the master or slave manipulator, γ _ij (k) is the lower bound of the joint angle change, The upper bound of the joint angle change;

Define the desired angular position for each joint angle also satisfied

Define two positive variables that satisfy

Define Bilateral Synchronization Error

Define toggle signal

Auxiliary symbols defined as follows

Step 3: Design a discrete-time bilateral control law and use it to control:

u _i (k) = v _i (k) + w _i (k)

Among them, θ _i and is a diagonal matrix with all nonzero elements positive

The absolute value of the difference between the limit boundary of the state variable and the initial value should not be less than 1, and _θi is selected as the reciprocal of the sampling period.

Beneficial effect

The present invention proposes a remote control-oriented discrete time variable boundary bilateral control method, establishes a discrete time remote control bilateral control system, and for a predetermined state boundary, combines the value characteristics of the state deviation to design the switching signal of the control law and design the discrete time Bilateral control law. The invention realizes the direct application of the state-bounded bilateral control method in the computer system, ensures bilateral synchronization, and ensures stable precision of the system through reasonable selection of parameters.

Detailed ways

Now in conjunction with embodiment the present invention will be further described:

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions:

A discrete-time enhanced bilateral control method with variable boundaries oriented to remote control, the steps of which include:

a) Consider a discrete-time teleoperated bilateral control system:

Among them, the subscripts m and s refer to the remote-controlled master and slave manipulators respectively. For the convenience of description, i=m, s are used to describe the subsequent variables, and k represents the sampling time. represents the joint intersection vector, represents the positive definite inertia matrix, represents the Coriolis force matrix, is an unknown but bounded external disturbance, represents the input force of the human operator, represents the environmental force, Indicates the torque output by the manipulator.

Convert the bilateral control model to obtain the following differential expression:

q _i (k+1)=q _i (k)+δΔq _i (k)

Δq _i (k+1)=Δq _i (k)+δf _i (k)+δg _i (k)u _i (k)+δd _i (k)

where δ represents the sampling interval of the discrete-time system, corresponding to the bilateral control model, and is easy to obtain

d _i (k)=-B _i (Δq _i (k))

Among them, F _i (k) corresponds to the environmental force and the input of the operator according to the situation;

b) For the predetermined state boundary, combined with the value characteristics of the state deviation, design the switching signal of the control law:

Design Synchronization Error:

e _m (k)=q _m (k)-q _s (kT _s )

e _s (k)=q _s (k)-q _m (kT _m )

Among them, the error of the master end is e _m (k), the error of the slave end is e _s (k), and T _m and T _s respectively represent the delay time of the master end and the slave end relative to the multiplier of the sampling interval. The joint angle limit of the bilateral manipulator is where q _ij (k) represents the angular position of the jth joint angle of the master or slave manipulator, and similarly, defines the desired angular position of each joint angle also satisfied Define two positive variables that satisfy

Define Bilateral Synchronization Error

Define toggle signal

Auxiliary symbols defined as follows

ξ _ij (k)=h _ij (k)η _ij (k)+(1-h _ij (k))ζ _ij (k)

c) Design a discrete-time bilateral control law;

u _i (k) = v _i (k) + w _i (k)

Among them, θ _i and is a diagonal matrix with all nonzero elements positive,

In order to ensure the synchronous stability of the bilateral system, the absolute value of the difference between the limit boundary of the state variable and the initial value should not be less than 1, and θ _i is recommended to be the reciprocal of the sampling period.

Claims (1)

1. A discrete time variable boundary bilateral control method for remote control, characterized in that the steps are as follows: Step 1: Discrete time remote control bilateral control system: Among them, the subscripts m and s refer to the remote-controlled master and slave manipulators respectively. For the convenience of description, i=m, s are used to describe the subsequent variables, and k represents the sampling time. represents the joint intersection vector, represents the positive definite inertia matrix, represents the Coriolis force matrix, is an unknown but bounded external disturbance, represents the input force of the human operator, represents the environmental force, Indicates the torque output by the mechanical arm; Convert the bilateral control model to obtain the following differential expression: q _i (k+1)=q _i (k)+δΔq _i (k) Δq _i (k+1)=Δq _i (k)+δf _i (k)+δg _i (k)u _i (k)+δd _i (k) where δ represents the sampling interval of the discrete-time system, corresponding to the bilateral control model, and obtains: d _i (k)=-B _i (Δq _i (k)) Among them, F _i (k) corresponds to the environmental force and the input of the operator according to the situation; Step 2: For the predetermined state boundary, combined with the value characteristics of the state deviation, design the switching signal of the control law: Synchronization error: Among them, the error of the master end is e _m (k), the error of the slave end is e _s (k), and T _m and T _s respectively represent the delay time of the master end and the slave end relative to the multiplier of the sampling interval. The joint angle limit of the bilateral manipulator is Where q _ij (k) represents the angular position of the jth joint angle of the master or slave manipulator, γ _ij (k) is the lower bound of the joint angle change, The upper bound of the joint angle change; Define the desired angular position for each joint angle also satisfied Define two positive variables that satisfy Define Bilateral Synchronization Error Define toggle signal Auxiliary symbols defined as follows Step 3: Design a discrete-time bilateral control law and use it to control: u _i (k) = v _i (k) + w _i (k) Among them, θ _i and is a diagonal matrix with all nonzero elements positive The absolute value of the difference between the limit boundary of the state variable and the initial value should not be less than 1, and _θi is selected as the reciprocal of the sampling period.