Powered attendant-propelled wheelchair with assist-as-needed control based on individual physical capabilities

Abstract

This paper discussed if a powered attendant propelled wheelchairs (PAPW) with assist-as-needed control reduces energy consumption and maximise attendant's physical activity in powered system use. This study introduced a PAPW with force velocity assist control (FVAC) based on individual capability of pushing force velocity relationship. This PAPW assists attendant pushing when more pushing force is needed over usual range of individual physical capabilities of pushing. With the PAPW, we investigated the performance of the FVAC and compared it with proportional assist control (PAC) on a flat level surface and a longitudinal slope (6.5%) with three participants. The experimental results showed that the PAPW with the FVAC reduced 50% of pushing force on the slope and this was similar performance of the PAC in terms of assisting. The FVAC also reduced 79% of mean mechanical assisting power on the flat against the PAC. These results support that the PAPW with the FVAC has flexibilities to adapt to individual physical capabilities and provides certain level of physical activities with sufficient assisting when needed, and low energy consumption for long time and distance operations for attendants.

An Analytical Modelling of Demand for Driving Torque of a Wheelchair with Electromechanical Drive

“…Moreover, the mechanisms and electrical systems used in them should also be characterized by the lowest possible energy consumption [35]. An electric assisted wheelchair is, in principle, a parallel hybrid (manual-electric) drive [36]. For this reason, when designing such devices, the mechanical parameters [37] should be taken into account, such as the location of the centre of gravity [38], the weight of the structure [39], the efficiency of mechanisms [40], as well as electrical parameters such as, for example, battery capacity [39], power and efficiency of drive units [41], etc.…”