Development of variable control mechanism to amplify operating range of end-effector of wearable haptic device (Design of the variable control mechanism and evaluation of haptic states)

Abstract

The objective of this study is to develop the variable control mechanism to amplify the operating range of the end-effector of the wearable haptic device. The conventional haptic devices are classified into passive haptic devices and active haptic devices by means of the force display conditions. The passive haptic device has a wide operating range and a high bandwidth of the dynamic characteristics in the force non-displayed condition. On the other hand, the active haptic device provides accurate resistive force for the operator by changing the posture of the device by the active actuators. In this study, the variable control mechanism which has both of these advantages is developed. The proposed mechanism is able to control the mechanical connection between the active actuator and the end effector of the haptic device. In addition, the force detection mechanism and the angle detection mechanism of the wrist for the force feedback control are developed to display an accurate force. The experiments of the transition between the unconstraint condition and the constraint condition of the end effector were carried out to confirm the effectiveness of the variable control mechanism. The experimental results show that the proposed haptic device with the proposed mechanism is able to improve the dynamic characteristics of the end-effector and to amplify the operating range of the end-effector of the wearable haptic device.