Reduction of Electric Energy Consumption in Drives with Controlled Gear Ratio

A novel method of reducing energy consumption by electric drive systems operating under strongly variable loads is proposed. It involves the use of a gearbox with a controlled gear ratio that is changed during the implementation of complex motion profiles. Positive results of preliminary simulation studies were experimentally confirmed by testing a modified drive system of an orthotic robot with three variants of the gear ratio: two different values of a constant gear ratio and a controlled gear ratio. A dedicated test stand and experimental methods are discussed. The obtained experimental results confirmed the effectiveness of the proposed method, namely that the energy consumption was reduced by 8% and 14.1% when using the gearbox with a controlled gear ratio.