Haptic Teleoperation of a Mobile Robot: A User Study

Abstract

The problem of teleoperating a mobile robot using shared autonomy is addressed: an onboard controller performs close range obstacle avoidance while the operator uses the manipulandum of a haptic probe to designate the desired speed and rate of turn. Sensors on the robot are used to measure obstacle range information. A strategy to convert such range information into forces is described, which are reflected to the operator's hand via the haptic probe. This haptic information provides feedback to the operator in addition to imagery from a front-facing camera mounted on the mobile robot. Extensive experiments with a user population both in virtual and in real environments show that this added haptic feedback significantly improves operator performance, as well as presence, in several ways (reduced collisions, increased minimum distance between the robot and obstacles, etc.) without a significant increase in navigation time.

Stability Analysis of Mobile Robot Teleoperation with Variable Force Feedback Gain

“…We consider feedback force based on the obstacle range information only (environmental force feedback). In conventional approach [1] the following basic law was used for calculating the force feedback:…”

“…The force f e is applied to operator through master device to the opposite direction of the obstacle. Experiments proved that the usage of environmental feedback force improves safety of teleoperation by reducing the number of collisions [1]. But, it was also shown that feedback force with constant feedback gain degrades the accuracy of mobile robot motion control [5].…”

“…In first case (k = 0), the mobile robot moved to desired position near the obstacle while the operator did not feel any force feedback. Absence of environmental force feedback could lead to collisions and teleoperation might not be safe [1]. In the case when k = 26, it was very difficult for the operator to stabilize position of the mobile robot due to the high impact from the force feedback.…”

“…There were several researches which addressed stability issues of MRT. In [1], it was shown experimentally that haptic feedback improves the safety of MRT. Passivity of such systems was studied in [2], but dynamics of operator and environment was not considered the model.…”

Improving mobile robot bilateral teleoperation by introducing variable force feedback gain

“…They also proved the passivity of the system which guaranteed the stability of haptic interaction. Similar approach was proposed by Lee et al in [2]. It was proposed to convert obstacle range information from mobile robot into force field reflected to human-operator.…”