SensHB.Q: A Cost-Effective Force-Sensitive Handlebar to Control Omnidirectional Robots and Wheelchairs

Abstract

This paper details the design and development of SensHB.Q, a force-sensitive handlebar intended for caregivers driving electric-powered wheelchairs, particularly those with omnidirectional mobility. The same interface can also be used in the future to operate other omnidirectional motorized systems, such as mobile robots, hospital beds, and industrial trolleys. The primary objective was to develop an intuitive, cost-effective device. To achieve this, the interface mimics the way we naturally interact with objects by applying forces and torques to achieve desired movements. SensHB.Q measures the forces and torques applied by the driver and converts them into commands for the motorized system. The idea is that the driver applies small forces and torques, and the motorized platform then takes care of the traction forces needed to perform the desired motion. In terms of cost-effectiveness, SensHB.Q uses a mechanism that only employs uniaxial load cells to measure the forces applied by the driver, thus avoiding the need for costly multiaxial load cells. This paper first presents the concept of SensHB, followed by a discussion of its functional and executive design. Second, the study elaborates on the electronic control unit of the device and presents experimental tests comparing the force/torque measurements of SensHB.Q with those of an off-the-shelf, six-axis force/torque sensor. Finally, SensHB.Q is integrated and tested on the omnidirectional motorized wheelchair MoviWE.Q, which was developed at Politecnico di Torino. These preliminary tests, which are performed with a limited number of participants, are used to test whether it is possible to drive an omnidirectional motorized system using the developed force-sensitive interface.