Motion capture system for end-positioning control of flexible manipulators

The flexible robotic arm is a new type of bionic robotic arm whose design is inspired by biological structures found in nature, such as elephant trunks, octopus claws, earthworms and snakes.Compared with traditional manipulators, flexible manipulators can bend any shape within the range of material deformation, and have strong adaptability to work in narrow and complex spaces by adjusting their shape.

Flexible robotic arms are often used in medical surgery, space rescue, equipment maintenance and other fields.In these scenarios, the operation accuracy of the end of the flexible manipulator is very high, but most researches focus on improving the repetitive positioning accuracy of the end control, ignoring the control error during the end trajectory tracking process, and the dynamic model of the flexible arm is difficult to be accurate.Establish.

Researchers from the School of Electrical Engineering of Sichuan University designed a rigid-flexible coupled wire-driven flexible manipulator. Through the analysis of the motion mechanism of the flexible manipulator, they designed a control scheme for the end positioning of the flexible manipulator based on the inverse dynamics model., and carried out simulation and physical prototype terminal positioning control experiments.

The physical prototype of the flexible manipulator is composed of the manipulator body, the driving device and the electric control system. The driving device drives the slide table to move through the motor and pulls the driving line to complete the motion control of the manipulator body.In order to accurately record the change data of the end position during the movement of the flexible manipulator, the researchers arranged the NOKOV metric optical motion capture system above the manipulator body, and placed a reflective marker ball at the end of the flexible arm, and used the motion capture camera to track the acquisition.Real-time data on end positions.In the experiment, the positioning accuracy of NOKOV metric motion capture system reaches sub-millimeter level.

The researchers compared the ideal trajectory with the simulated trajectory and the actual trajectory (collected by the NOKOV metric motion capture system), and analyzed the reasons for the errors of the physical prototype.The experimental results show the effectiveness of the end-positioning control algorithm based on the inverse dynamics model.

 

References:[1]Ma Congjun, Zhao Tao, Xiang Guofei, Ren Jiangtao, Chen Yuanke, Tsun Songyi. Based on inverse kinematicsPositioning control of the end of a flexible manipulator[J].Chinese Journal of Mechanical Engineering,2021,57(13):163-171.

Read more:

Robot Spatial Positioning Pose | NOKOV Metric Motion CaptureNOKOV MetricMotion capture can provide high-precision six-degree-of-freedom kinematic data to achieve precise positioning of the robotic armhttps://www.nokov.com/motion-capture-robotic-arm.htmlClassic Case | NOKOV Metric Motion CaptureClassic casehttps://www.nokov.com/support/case_studies/6.html#case-list-1p>