Study on the control of the variable-structure-type locomotive robot. (1st report. Postural and driving control of the controlling arm-wheel type).

Abstract

The authors have developed a variable-structure-type locomotive robot which can undertake three variations of locomotion according to the working environment or application of the robot. The first variation is an arm-wheel-type, the second and the third are an arm-leg-type and a leg-leg-type, respectively. This paper reports the control methods and experimental results on the postural and driving control of the arm-wheel-type locomotive robot which has a twin wheel, an upper structure on its driving axis and double controlling arms suspended from the upper body. In order to stabilize the posture of the robot, feedback control based on the compound gravity center between the body and the arms has been proposed to control the arms, with which we have succeeded in establishing the postural stability of the vehicle. Furthermore, proportional and integral feedback controls concerning the arm angle or the inclination of the body together with the gravity feedback have enabled the body inclination to be controlled while following a prescribed path. Standing rest and servo-driving control of the vehicle were also attained by controlling the wheel independently from the arms.