Title :
Kinematic batch calibration for legged robots
Author :
Bloesch, Michael ; Hutter, Marcus ; Gehring, Christian ; Hoepflinger, Mark A. ; Siegwart, R.
Author_Institution :
Autonomous Syst. Lab., ETH Zurich, Zurich, Switzerland
Abstract :
This paper introduces a novel batch optimization based calibration framework for legged robots. Given a non-degenerate calibration dataset and considering the stochastic models of the sensors, the task is formulated as a maximum likelihood problem. In order to facilitate the derivation of consistent measurement equations, the trajectory of the robot and other auxiliary variables are included into the optimization problem. This formulation can be transformed into a nonlinear least squares problem which can be readily solved. Applied to our legged robot StarIETH, the framework estimates kinematic parameters (segment lengths, body dimensions, angular offsets), accelerometer and gyroscope biases, as well as full inter-sensor calibrations. The generic structure easily allows the inclusion of additional sensor modalities. Based on datasets obtained on the real robot the consistency and performance of the presented approach are successfully evaluated.
Keywords :
calibration; least squares approximations; legged locomotion; maximum likelihood estimation; optimisation; robot kinematics; sensors; stochastic processes; StarlETH legged robot; accelerometer; angular offsets; auxiliary variables; body dimensions; consistent measurement equations; generic structure; gyroscope biases; intersensor calibration; kinematic batch optimization-based calibration framework; kinematic parameter estimation; maximum likelihood problem; nondegenerate calibration dataset; nonlinear least squares problem; robot trajectory; segment lengths; sensor modality inclusion; stochastic sensor models; Calibration; Kinematics; Legged locomotion; Robot kinematics; Robot sensing systems;
Conference_Titel :
Robotics and Automation (ICRA), 2013 IEEE International Conference on
Conference_Location :
Karlsruhe
Print_ISBN :
978-1-4673-5641-1
DOI :
10.1109/ICRA.2013.6630924