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;
the wheel configured and arranged to receive power from the electric motor;
a controller operative to (i) receive acceleration commands and wheel slip information for the wheel as inputs, wherein the wheel slip information comprises a measurement of a time from an application of a maximum torque until slippage of the wheel starts, 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 having fixed frequency and fixed duration within the timing cycle to cause current to flow to the electric motor during an ON state of the timing cycle, wherein a first pulse of the series of pulses with wheel slip is measured by monitoring and recording a first time duration of the first pulse comprising the time from the application of the maximum torque until slippage of the wheel starts and a second recovery time duration of the first pulse, and using the first and second recovery time durations to generate subsequent pulses of the series of pulses in 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 the ON state and an OFF state 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.
892 Citations
61 Claims
-
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; the wheel configured and arranged to receive power from the electric motor; a controller operative to (i) receive acceleration commands and wheel slip information for the wheel as inputs, wherein the wheel slip information comprises a measurement of a time from an application of a maximum torque until slippage of the wheel starts, 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 having fixed frequency and fixed duration within the timing cycle to cause current to flow to the electric motor during an ON state of the timing cycle, wherein a first pulse of the series of pulses with wheel slip is measured by monitoring and recording a first time duration of the first pulse comprising the time from the application of the maximum torque until slippage of the wheel starts and a second recovery time duration of the first pulse, and using the first and second recovery time durations to generate subsequent pulses of the series of pulses in 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 the ON state and an OFF state 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, 23)
-
-
24. 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:
-
providing a timing cycle; determining a desired acceleration rate for a vehicle powered by one or more electrically driven wheels; based on receiving acceleration commands and wheel slip information for the one or more wheels, wherein the wheel slip information comprises a measurement of a time from an application of a maximum torque until slippage of one of the wheels starts, generating a control signal for each of the one or more wheels including a series of pulses having fixed frequency and fixed duration within the timing cycle corresponding to the desired acceleration rate, wherein a first pulse of the series of the pules with wheel slip is measured by monitoring and recording a first time duration of the first pulse comprising the time from the application of the maximum torque until slippage of one of the wheels starts and a second recovery time duration of the first pulse, and using the first and second recovery time durations to generate subsequent pulses of the series of pulses in the timing cycle; and supplying the control signal to a respective input of each of one or more current switches, each current switch being connected to an electric motor, each electric motor being connected to a respective one of the wheels, to place the respective switch in one of an ON state during each of the series of pulses and an OFF state after each of the series of pulses 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 (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
-
-
42. A computer program product residing on a non-transitory computer-readable storage medium having a plurality of instructions stored thereon, which when executed by a processing system, cause the processing system to:
-
provide a timing cycle; determine a desired acceleration rate for a vehicle powered by one or more electrically driven wheels; based on acceleration commands and wheel slip information for the one or more wheels, wherein the wheel slip information comprises a measurement of a time from an application of a maximum torque until slippage of one of the wheels starts, generate a control signal for each of the one or more wheels including a series of pulses having fixed frequency and fixed duration within the timing cycle corresponding to the desired acceleration rate, wherein a first pulse of the series of pulses with wheel slip is measured by monitoring and recording a first time duration of the first pulse comprising the time from the application of the maximum torque until slippage of one of the wheels starts and a second recovery time duration of the first pulse, and using the first and second recovery time durations to generate subsequent pulses in the timing cycle; and supply the control signal to a respective input of one or more current switches, each current switch being connected to an electric motor, each electric motor being connected to a respective one of the wheels, to place the respective switch in one of an ON state during each pulse of the series of pulses and an OFF state after each pulse to cause of the series of pulses 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 (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61)
-
Specification