Vehicle speed estimation system
AssigneeToyota Motor Engineering & Manufacturing North America, Inc.
InventorsLaura E. Bower, Rebecca L. Kemph
Life of this patent
Estimating the term…
Abstract
Disclosed is a system for estimating the speed of a vehicle. The system includes a plurality of wheel rotation sensors, a grade sensor, an acceleration sensor, an accelerator pedal deflection sensor, a brake pedal deflection sensor, and a processor. The processor is configured to compute a linear wheel speed, an upper limit of vehicle speed, and a lower limit of vehicle speed, based on the grade information, the pedal deflection information, and the acceleration, and then compute an estimated speed of the vehicle based on the linear wheel speed, the upper limit of vehicle speed, and the lower limit of vehicle speed.
Claims19
A system for estimating a speed of a vehicle, comprising:
- a plurality of wheel rotation sensors, each configured to provide rotation speed information of a corresponding wheel of the vehicle;
- a grade sensor configured to provide grade information of a ground surface beneath the vehicle;
- an acceleration sensor configured to provide acceleration information of the vehicle;
- a first pedal deflection sensor configured to provide a first pedal deflection information of an accelerator pedal of the vehicle;
- a second pedal deflection sensor configured to provide a second pedal deflection information of a brake pedal of the vehicle;
- a processor configured to:
- compute a linear wheel speed based on the rotation speed information of the wheels of the vehicle;
- compute an upper limit of vehicle speed and a lower limit of vehicle speed, based on the grade information, the first pedal deflection information, the second pedal deflection information, and the acceleration information;
- and
- compute an estimated speed of the vehicle based on the linear wheel speed, the upper limit of vehicle speed, and the lower limit of vehicle speed.
A method for estimating a speed of a vehicle, the method comprising:
- measuring rotation speeds of at least one wheel of the vehicle;
- based on the rotation speeds of the at least one wheel of the vehicle, computing a linear wheel speed;
- obtaining grade information for a ground surface beneath the vehicle;
- measuring a first pedal deflection of an accelerator pedal of the vehicle;
- measuring a second pedal deflection of a brake pedal of the vehicle;
- measuring an acceleration of the vehicle;
- based on the grade information, the first pedal deflection, the second pedal deflection, and the acceleration of the vehicle, computing an upper limit of vehicle speed and a lower limit of vehicle speed;
- and
- selecting a speed estimate based on a second-largest value from the group comprising:
- the linear wheel speed, the upper limit of vehicle speed, and the lower limit of vehicle speed.
A method for estimating a speed of a vehicle, the method comprising:
- measuring rotation speeds of at least one wheel of the vehicle;
- based on the rotation speeds of the at least one wheel of the vehicle, computing a change in a linear wheel speed over a defined period of time;
- obtaining grade information for a ground surface beneath the vehicle;
- measuring a first pedal deflection of an accelerator pedal of the vehicle;
- measuring a second pedal deflection of a brake pedal of the vehicle;
- measuring an acceleration of the vehicle;
- based on the grade information, the first pedal deflection, the second pedal deflection, and the acceleration of the vehicle, computing an upper limit of a change in vehicle speed over the defined period of time and a lower limit of the change in vehicle speed over the defined period of time;
- and
- selecting a speed estimate equal to a previous speed of the vehicle plus a second-largest value from among the group comprising:
- the change in the linear wheel speed over the defined period of time, the upper limit of the change in vehicle speed over the defined period of time, and the lower limit of the change in vehicle speed over the defined period of time.
Dependencies are inferred from the claim text.