Development of Six-Axis Force Sensor Using Plate Spring
Yoichi Muranaka, Raifu Murai,* Masakazu Takahashi,** and Genichiro Kinoshita
Faculty of Science and Engineering, Chuo University
1-13-27, Kasuga, Bunkyo-ku, Tokyo 112, Japan
*Olympus Optical Co., Ltd.
1-22-1, Nisfii~Shinjuku, Shinjuku-ku, Tokyo 160, Japan
**Fuji Xerox Co., Ltd.
3-3-5, Akasaka, Minato-ku, Tokyo 107, Japan
This paper describes a six-axis force sensor for robot manipulators which consists of a cross-shaped plate spring formed from a 160mmx160mm, lmm thick beryllium- copper plate. The plate spring is twisted through a 90° angle at the mid-point of each branch of the crossshaped spring so that it consists of eight flat springs aligned on two orthogonal axes. Six components of the force/.torque vector acting on the end-effector are measured using strain gauges cemented at sixteen locations of the plate spring. Optimal locations of strain gauges are determined through the calculation of strain distri~ ution caused by each component of the force/torque vector. A simple setup for calibration of the sensor, which consists of a pair of commercial linear guides, a pair of force indicating meters, and a pair of micrometer heads, is presented. The performance characteristics of the sensor are examined in detail.