US 12,485,768 B2
Control of torque in electric lift trucks
Janne Laaksonen, Riihimäki (FI)
Assigned to Mitsubishi Logisnext Europe Oy, Järvenpää (FI)
Appl. No. 17/763,884
Filed by Mitsubishi Logisnext Europe Oy, Järvenpää (FI)
PCT Filed Sep. 23, 2020, PCT No. PCT/FI2020/050616
§ 371(c)(1), (2) Date Mar. 25, 2022,
PCT Pub. No. WO2021/058864, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 20195825 (FI), filed on Sep. 27, 2019.
Prior Publication US 2022/0340017 A1, Oct. 27, 2022
Int. Cl. B60L 15/20 (2006.01); B66F 9/075 (2006.01)
CPC B60L 15/20 (2013.01) [B66F 9/07572 (2013.01); B60L 2200/42 (2013.01); B60L 2240/12 (2013.01); B60L 2240/16 (2013.01); B60L 2240/36 (2013.01); B60L 2240/423 (2013.01); B60L 2240/425 (2013.01); B60L 2250/26 (2013.01); B60L 2260/167 (2013.01); B60L 2260/42 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for controlling a torque generated by at least one electric motor of an electric lift truck, the method performed by a control unit of the electric lift truck, comprises:
detecting a fulfilment of at least one criterion when the torque of the at least one electric motor is in a first mode corresponding to a mode in which the at least one electric motor is caused to generate a nominal torque of the at least one electric motor, the control unit defining a target speed of the electric lift truck and a maximum speed deviation in conjunction with the detection of the fulfilment of the at least one criterion, a detection of the fulfilment of the at least one criterion indicating insufficient amount of the torque in the first mode to maintain a motion of the electric lift truck being performed on a basis of a change in the motion of the electric lift truck, the at least one criterion comprising an input to the control unit of one of an actual speed value of the electric lift truck or an actual acceleration value of the electric lift truck,
determining a current output to increase the actual speed of the electric lift truck to the target speed automatically without a user interaction through a user interface of the electric lift truck, and operating an electrical drive of the at least one electric motor to generate a control signal to the at least one electric motor to generate, in a temporal basis, a torque being larger than the torque of the at least one electric motor in the first mode to change the torque to an increased torque mode for maintaining the motion of the electric lift truck.