Motion compensation for on-board vehicle sensors

• US 10,235,817 B2
• Filed: 09/01/2015
• Issued: 03/19/2019
• Est. Priority Date: 09/01/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Saeger, Martin, Micks, Ashley Elizabeth
• Primary Examiner(s): Merlino, David P.
• Application Number:
  US14/842,621
• Publication Number:
  US 20170061710A1
• Time in Patent Office: 1,295 Days
• Field of Search: None
• CPC Class Codes: B60W 40/06 Road conditions
• CPC Class Codes: G01C 7/04 involving a vehicle which moves along the profile to be traced
• CPC Class Codes: G07C 5/02 Registering or indicating driving, working, idle, or waiting time only apparatus forming part of taximeters G07B13/00

Abstract

A method for improving the accuracy with which a road profile ahead of a vehicle may be determined. The method may include receiving a plurality of inputs corresponding to a plurality of on-board sensors corresponding to a vehicle. An on-board computer system may estimate motion of the vehicle. The on-board computer system may correct data corresponding to a forward-looking sensor of the plurality of on-board sensors by accounting for the motion of the vehicle. Accordingly, the on-board computer system may use the corrected data to produce more accurate information characterizing the driving environment ahead of the vehicle. This more accurate information may be used to better estimate the motion of the vehicle in the future as the vehicle encounters that driving environment, which may improve the corrections that may be applied to the data corresponding to the forward-looking sensor at that time.

Claims

1. A method comprising:

carrying on-board, by a vehicle, a computer system and a plurality of sensors;

receiving, by the computer system, first data characterizing one or more conditions sensed by the plurality of sensors at a particular moment in time;

estimating, by the computer system based on the first data, an expected amount of movement of the vehicle at a future time after the particular moment in time with respect to a reference coordinate system at the particular moment in time based on a feature located in front of the vehicle and detected in the first data;

defining a transformation according to the estimating of the expected amount of movement of the vehicle relative to the reference coordinate system; and

receiving, by the computer system, second data characterizing one or more conditions sensed at the future time by one or more sensors of the plurality of sensors when the feature is located under the vehicle;

correcting, by the computer system, the second data by transforming a plurality of coordinates in the second data from a sensor coordinate system to the reference coordinate system according to the transformation.

2. The method of claim 1, wherein at least one of the one or more sensors comprises a forward-looking sensor characterizing a driving environment ahead of the vehicle.

3. The method of claim 2, further comprising producing, by the computer system, information characterizing the driving environment ahead of the vehicle.

4. The method of claim 3, wherein each sensor of the one or more sensors is selected from the group consisting of an ultrasonic transducer, a laser scanner, and a lidar scanner.

5. The method of claim 1, wherein the estimating comprises correcting a predicted motion of the vehicle with the first data.

6. The method of claim 5, wherein the correcting the predicted motion comprises applying a Kalman filter.

7. The method of claim 6, wherein the first data characterize the attitude of a body of the vehicle in at least one of pitch, roll, and yaw.

8. The method of claim 6, further comprising producing, by the computer system, the predicted motion.

9. The method of claim 8, wherein at least one of the one or more sensors comprises a forward-looking sensor directed to an area in front of the vehicle.

10. The method of claim 9, wherein estimating the expected amount of movement of the vehicle at the future time comprises:

using, by the computer system, the first data to profile a portion of road ahead of the vehicle at the particular moment in time; and

using, by the computer system, a virtual, vehicle-motion model and the profile to generate the expected amount of movement.

11. A method comprising:

carrying, by a vehicle, an on-board computer system and a plurality of on-board sensors;

receiving, by the on-board computer system, a first plurality of inputs characterizing one or more first conditions sensed by the plurality of on-board sensors at a particular moment in time;

estimating, by the on-board computer system based on one or more inputs of the first plurality of inputs, expected movement of a body of the vehicle in terms of heave, pitch, yaw, and roll with respect to a reference coordinate system at a future time according to at least one feature detected in front of the vehicle in the one or more inputs of the first plurality of inputs;

defining, by the on-board computer system, a transformation matrix according to the estimating of the expected movement of the body of the vehicle in terms of heave, pitch, yaw, and roll with respect to the reference coordinate system; and

receiving, by the on-board computer system, a second plurality of inputs characterizing one or more second conditions sensed by a forward-looking sensor of the plurality of on-board sensors at a time when the at least one feature is under the vehicle;

correcting, by the on-board computer system, data characterizing the one or more second conditions by multiplying a plurality of coordinates in a portion of the second plurality of inputs received from the forward-looking sensor by the transformation matrix to obtain corrected coordinates.

12. The method of claim 11, wherein the forward-looking sensor is selected from the group consisting of an ultrasonic transducer, a laser scanner, and a lidar scanner.

13. A vehicle comprising:

a plurality of on-board sensors producing sensor coordinates in a sensor coordinate system;

an on-board computer system; and

an on-board data acquisition system converting signals from the plurality of on-board sensors to a plurality of inputs processable by the on-board computer system;

the on-board computer system comprising memory and at least one processor operably connected to the memory, the memory storing

a motion-estimation module programmed to estimate, based at least in part on one or more inputs of the plurality of inputs, expected movement of the vehicle at a future time with respect to a reference coordinate system in response to a feature sensed in front of the vehicle at a particular moment in time, the future time being a future time when the feature will be under the vehicle, and

a motion-compensation module programmed to;

generate a transformation matrix according to the estimating of the expected movement of the vehicle with respect to the reference coordinate system; and

correct data characterizing a condition sensed by one or more sensors of the plurality of on-board sensors after the particular moment in time when the feature is under the vehicle by multiplying the sensor coordinates in the data characterizing the condition by the transformation matrix to obtain corrected coordinates.

14. The vehicle of claim 13, wherein at least one of the one or more sensors comprises an on-board, forward-looking sensor characterizing a driving environment ahead of the vehicle.

15. The vehicle of claim 14, wherein the memory further stores a sensor-evaluation module programmed to output information characterizing the driving environment ahead of the vehicle.

16. The vehicle of claim 13, wherein the motion-estimation module is further programmed to apply a Kalman filter to estimate the expected movement of the vehicle at the future time when the feature is under the vehicle.

17. The vehicle of claim 16, wherein each sensor of the one or more sensors is selected from the group consisting of an ultrasonic transducer, a laser scanner, and a lidar scanner.