Research > Robotics > Intelligent Control of Robot Manipulators > Automatic Sensor Frame Identication

Automatic Sensor Frame Identication

Motivation and Approach

In industrial applications, sensor mounting locations may vary due to task variations, which leads to frequent needs of sensor frame calibration. To simplify the calibration process, and to ensure the accuracy of the state estimation in robot manipulators, an automatic sensor frame identication process is developed. This process detects the sensor’s mounting position and orientation by updating the estimate of the sensor parameter “a” (i.e., the sensor frame location) using multiple sensor signals over a designed trajectory.

1. Design a nonlinear observer (blue shaded area) that provides accurate estimates of robot states.
2. Decouple the sensor frame identication problem (orange shaded area) as two separate problems:
   1. Estimate the robot states using an estimate of the sensor parameter.
   2. Optimize the sensor parameter by solving the Maximum Likelihood estimation problem
      using the estimates of robot states.

 

Main Results

1. Automation of the calibration process for load side accelerometer: applications to single-joint robot and multi-joint robots with joint elasticity [1].
2. Observer design for robot manipulators with joint elasticity: the extended Kalman filter (EKF) based [1] and the stochastic piecewise affine (PWA) model based approaches.

 

Recent Key Publications

1. C.-Y. Lin, W. Chen, and M. Tomizuka, "Automatic sensor frame identication in industrial robots with joint elasticity," in Proceedings of the 2013 ASME Dynamic Systems and Control Conference (DSCC), October 21-23, 2013