ELECTRIC VEHICLE TRACTION CONTROL SYSTEM AND METHOD
First Claim
1. A method for controlling and maintaining optimal traction between wheels of a vehicle equipped with one or more drive wheels electrically powered to drive the vehicle and a drive surface on which said vehicle is driven comprising:
- a. equipping a vehicle with one or more electric drive motors controllable to translate torque through one or more vehicle drive wheels to drive said vehicle on a drive surface, and providing a source of electric power supplying electric current to the one or more electric drive motors through one or more inverters, a vehicle operator input in communication with the one or more inverters and with a processor and a controller;
b. programming the processor to automatically select a motor torque/speed curve for the one or more electric drive motors that defines optimal vehicle speed and traction on the drive surface and produces a motor commanded torque at an expected rotor speed;
c. communicating a vehicle operator input comprising at least desired vehicle speed, motor commanded torque from desired vehicle speed, rotor speed, motor stator temperature, and available inverter voltage to the processor and setting the motor commanded torque at the expected rotor speed corresponding to the selected motor torque/speed curve in response to the communicated vehicle operator input;
d. automatically determining a maximum electric current to be supplied to the one or more electric drive motors to produce the motor commanded torque at the expected rotor speed to drive the one or more drive wheels on the drive surface; and
e. automatically controlling the supply of electric current from the source of electric power to direct the determined maximum electric current to the one or more inverters in accordance with the selected motor torque/speed curve, maintaining the maximum electric current, and driving the vehicle with optimal traction on the drive surface.
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Accused Products
Abstract
A traction control system and method are provided for electric vehicles with at least one drive wheel powered by an electric drive motor to maintain optimum maximum traction while the vehicle is driven on the ground. The traction control system includes drive means capable of transmitting torque through a vehicle drive wheel and controllable to move the vehicle over a ground surface. A preferred drive means is an electric motor designed to move the vehicle at desired ground speeds in response to operator input. Operator input requests a desired speed, and the system determines drive wheel torque required to produce the desired speed and provides maximum current to produce maximum torque to drive the vehicle with optimum traction at the desired speed. The system uses constant feedback to find maximum current corresponding to torque required for an inputted speed request to automatically control traction in any electric powered vehicle.
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Citations
16 Claims
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1. A method for controlling and maintaining optimal traction between wheels of a vehicle equipped with one or more drive wheels electrically powered to drive the vehicle and a drive surface on which said vehicle is driven comprising:
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a. equipping a vehicle with one or more electric drive motors controllable to translate torque through one or more vehicle drive wheels to drive said vehicle on a drive surface, and providing a source of electric power supplying electric current to the one or more electric drive motors through one or more inverters, a vehicle operator input in communication with the one or more inverters and with a processor and a controller; b. programming the processor to automatically select a motor torque/speed curve for the one or more electric drive motors that defines optimal vehicle speed and traction on the drive surface and produces a motor commanded torque at an expected rotor speed; c. communicating a vehicle operator input comprising at least desired vehicle speed, motor commanded torque from desired vehicle speed, rotor speed, motor stator temperature, and available inverter voltage to the processor and setting the motor commanded torque at the expected rotor speed corresponding to the selected motor torque/speed curve in response to the communicated vehicle operator input; d. automatically determining a maximum electric current to be supplied to the one or more electric drive motors to produce the motor commanded torque at the expected rotor speed to drive the one or more drive wheels on the drive surface; and e. automatically controlling the supply of electric current from the source of electric power to direct the determined maximum electric current to the one or more inverters in accordance with the selected motor torque/speed curve, maintaining the maximum electric current, and driving the vehicle with optimal traction on the drive surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification