A Novel Constant Driving-Force Lift Mechanism with Sensorless Load Estimation for Scissor Lift Trolley

In this paper, we proposed a novel lift mechanism in which the input-output ratio of force between the actuator and the lift table can be designed arbitrarily. The mechanism can realize ideal force characteristics that match the application, and it is possible to improve work efficiency, such as in the logistics industry. Also, to take advantage of this mechanism, the mechanism with a constant input-output ratio of force is designed. Since the proposed mechanism can suppress variation of the friction force due to the table and the load, a force sensorless load estimation method is proposed. The proposed mechanism and the force sensorless load estimation were confirmed through the verification experiments. The results show that the proposed mechanism has the designed constant driving force within 10.9 N of SD. Also, the sensorless load estimation method was verified. The estimation error is within 15N of RMS from the low position to the high position.