Automated calibration system and calibration method for flexible robot actuator

An automated calibration method for a flexible robot actuator by using the automated calibration system for a flexible robot actuator, wherein the method comprises:

• A:
• calibration of input pneumatic pressure and output displacement:
• fixing an actuating end of the flexible actuator to a flexible actuator bracket, controlling a value of pneumatic pressure in the flexible actuator to increase from zero to a maximum pneumatic pressure value with a step of a minimum calibration unit by a pneumatic pressure control system, collecting images under different pneumatic pressures by camera systems, calculating to obtain displacements and angles of the actuator under different pneumatic pressures, and recording specific values of data;
• and
• B:
• calibration of output force of input pneumatic pressure at different bending angles:
• obtaining output displacements and angles of the flexible actuator under different pneumatic pressures according to step A, then adjusting a horizontal axis motor system, a vertical axis motor system and a rotating motor system to make a measuring end of a pressure gauge, that is, a force bearing point of the pressure gauge in contact with a perpendicular point of a free end of the flexible actuator, and carrying out specific numerical analysis for movement as follows:
• set a point of intersection of a horizontal axis motor and a vertical axis motor be the origin of coordinate axes, an axis of the horizontal axis motor system be the X-axis, an axis of the vertical axis motor system be the Y-axis, A be a midpoint of a line segment of an end portion at an actuating end of the flexible actuator and B be a midpoint of a line segment of an end portion at a free end of the flexible actuator, points A and B are connected to form a line segment LAB, an included angle between the line segment LAB and the X-axis is θ, a perpendicular to the line segment of the end portion at the actuating end of the flexible actuator is made through the point B with a point O as the foot, let Y=LBO, X=LAO,
• an auxiliary line LAF parallel to the Y-axis is made through the point A, an auxiliary line LBE parallel to the vertical axis is made through the point B,
• an auxiliary line LAD perpendicular to LAO is made through the point A, and a perpendicular LBO to a fixed end of the flexible actuator is made through the point B:
• wherein when θ=0, the pressure gauge is just at a tail end of the actuator, and in this case, a coordinate output of the X-axis motor is −Y1, a coordinate output of the Y-axis motor is 0, and an output of a Z-axis motor is 0;
• when θ>0, as the rotating motor rotates counterclockwise by the angle θ, the tail end of the actuator is perpendicular to a force bearing end of the pressure gauge, and the following formulae are obtained through analysis:
• L
• AB
• =
• (
• X
• 2
• +
• Y
• 2
• )
• ,
• ∠
• DAE
• =
• π
• 2
• -
• θ
• ,
• ∠
• EAO
• =
• θ
• ,
• ∠
• BAE
• =
• α
• -
• ∠
• EAO
• ,
• wherein
• α
• =
• ∠
• BAO
• =
• arc
• ⁢
• tan
• (
• Y
• X
• )
• ,
• the following formulae are obtained:
• LBE=sin∠BAE*LAB,
• LAE=cos∠BAE*LAB
• in this case, the coordinate output of the X-axis motor is −LAE, the coordinate output of the Y-axis motor is LBE, thus the outputs of the three motor axes of each (X, Y, θ) point are obtained based on the displacements and angles of the actuator under different pneumatic pressures obtained in step A, the value of pneumatic pressure in the flexible actuator is controlled to increase from zero to the maximum pneumatic pressure value with the step of the minimum calibration unit by the pneumatic pressure control system, and data of the pressure gauge is recorded, thereby completing the calibration.