TRACTION SYSTEM FOR ELECTRICALLY POWERED VEHICLES
First Claim
1. A system for controlling power applied to one or more drive wheels of a vehicle, the system comprising:
- an electric motor configured and arranged to supply power for driving a wheel;
a wheel configured and arranged to receive power from the electric motor;
a controller configured and arranged to (i) receive acceleration commands and wheel slip information for the wheel as inputs, and (ii) produce as an output a control signal for the electric motor driving the wheel, wherein the control signal includes a timing cycle with a series of pulses of fixed duration and fixed frequency within the timing cycle to cause current to flow to the electric motor during an ON component of the timing cycle; and
a current switch connected to the electric motor including an input to receive the control signal to place the switch in one of an ON state and an OFF according to the timing cycle.
4 Assignments
0 Petitions
Accused Products
Abstract
Fixed frequency, fixed duration pulse streams are used to control power switches for one or more electrical motors of electrically powered vehicles or hybrid vehicles having one or more electric motors. The advantages of a pulse system are increased power efficiency and system simplicity over analog systems. The capability of system calibration with a single pulse allows the system to be used under any conditions, and real time adaptation to changes in conditions. Such system and methods provide much improved acceleration over other electrical systems, by making the best use of the coefficient of starting or static friction. The systems and methods provide a non slip traction control system, and the use of an off state in the pulse stream is superior to the use of braking systems for the same purpose, which waste power and cause mechanical wear. In addition, related computer program products are described.
119 Citations
59 Claims
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1. A system for controlling power applied to one or more drive wheels of a vehicle, the system comprising:
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an electric motor configured and arranged to supply power for driving a wheel; a wheel configured and arranged to receive power from the electric motor; a controller configured and arranged to (i) receive acceleration commands and wheel slip information for the wheel as inputs, and (ii) produce as an output a control signal for the electric motor driving the wheel, wherein the control signal includes a timing cycle with a series of pulses of fixed duration and fixed frequency within the timing cycle to cause current to flow to the electric motor during an ON component of the timing cycle; and a current switch connected to the electric motor including an input to receive the control signal to place the switch in one of an ON state and an OFF according to the timing cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method for controlling the power applied to one or more electric motors coupled to one or more wheels of an electrically powered vehicle, the method comprising:
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providing a timing cycle; determining a desired acceleration rate for a vehicle powered by one or more electrically driven wheels; generating a control signal including a series of pulses of fixed duration and fixed frequency within the timing cycle corresponding to the desired acceleration rate; and supplying control signal to an input of a current switch connected to one or more electric motors, each connected to a respective one of the one or more wheels, to place the switch in one of an ON state during each pulse and an OFF state after each pulse to cause current to flow to the respective electric motor connected to each electrically driven wheel during the ON state and cause the respective electric motor to supply a desired power to each electrically driven wheel over the timing cycle. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A computer program product residing on a computer-readable storage medium having a plurality of instructions stored thereon, which when executed by a processing system, cause the processing system to:
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provide a timing cycle; determine a desired acceleration rate for a vehicle powered by one or more electrically driven wheels; generate a control signal including a series of pulses of fixed duration and fixed frequency within the timing cycle corresponding to the desired acceleration rate; and supply a control signal to an input of a current switch connected to one or more electric motors, each connected to a respective one of the one or more wheels, to place the switch in one of an ON state during each pulse and an OFF state after each pulse to cause current to flow to the respective electric motor connected to each electrically driven wheel during the ON state and cause the respective electric motor to supply a desired power to each electrically driven wheel over the timing cycle. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59)
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Specification