Model checking for autonomous vehicles

• US 9,315,178 B1
• Filed: 04/13/2012
• Issued: 04/19/2016
• Est. Priority Date: 04/13/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Ferguson, David I., Dolgov, Dmitri A., Urmson, Christopher
• Primary Examiner(s): Jabr, Fadey
• Assistant Examiner(s): Mahne, Kevin P
• Application Number:
  US13/446,025
• Time in Patent Office: 1,467 Days
• US Class Current: 1/1
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 17/221 Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M
• CPC Class Codes: B60T 2270/40 Failsafe aspects of brake control systems
• CPC Class Codes: B60T 2270/406 Test-mode; Self-diagnosis
• CPC Class Codes: B60T 8/171 Detecting parameters used in the regulation; Measuring values used in the regulation
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B60W 2050/021 Means for detecting failure or malfunction
• CPC Class Codes: B60W 2050/0292 Fail-safe or redundant systems, e.g. limp-home or backup systems
• CPC Class Codes: B60W 2050/143 Alarm means
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2420/42 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2510/18 Braking system
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2756/10 Involving external transmission of data to or from the vehicle
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 50/0097 : Predicting future conditions
• CPC Class Codes: B60W 50/0205 : Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: B60W 50/04 : Monitoring the functioning of the control system

Abstract

In an example method, a vehicle configured to operate in an autonomous mode could predict an output of the vehicle based on an input provided to control the vehicle and a state of the vehicle. The method could include receiving an indication of an input from at least one input-indication sensor and an indication of an output from at least one output-indication sensor. A predicted output value could be calculated based on the indication of the input and a state of the vehicle. The predicted output value could be compared with the indication of the output. If the comparison is not within a threshold range, an alert indicator could be created. Upon creating the alert indicator, an alert action could be activated.

Claims

1. An apparatus comprising:

at least one input-indication sensor configured to provide an indication of an input provided to a braking system of a vehicle, wherein the vehicle is operating the braking system in an autonomous mode;

at least one output-indication sensor configured to provide an indication of an output associated with the braking system of the vehicle;

a processor configured to;

i) calculate a predicted output value associated with the braking system based on the indication of the input received from the at least one input-indication sensor, a state of the vehicle, and on a coefficient indicative of a value used to at least partially compensate for a change in a performance of the braking system of the vehicle, wherein the predicted output value associated with the braking system is further based on a wear coefficient indicative of wear associated with the braking system;

ii) compare the predicted output value with the indication of the output; and

iii) if the comparison is not within a threshold range, create an alert indicator indicative of a malfunction of the braking system of the vehicle; and

a computing system having an alert module for activating an alert action responsive to the processor creating the alert indictor.

2. The apparatus of claim 1, wherein the wear coefficient indicative of wear associated with the braking system is a calculated wear coefficient associated with the braking system of the vehicle.

3. The apparatus of claim 1, wherein the wear coefficient indicative of wear associated with the braking system is a measured wear coefficient associated with the braking system of the vehicle.

4. The apparatus of claim 1, wherein the at least one input-indication sensor is configured to measure a pressure applied to a pedal of the vehicle.

5. The apparatus of claim 1, wherein the at least one input-indication sensor is configured to measure an electrical signal.

6. The apparatus of claim 1, wherein the at least one output-indication sensor is configured to measure a speed associated with the vehicle.

7. The apparatus of claim 1, wherein the at least one output-indication sensor is configured to measure a Global Positioning System signal.

8. The apparatus of claim 1, wherein the alert action comprises operating the vehicle in a safety mode.

9. The apparatus of claim 1, wherein the alert action comprises stopping a movement of the vehicle.

10. The apparatus of claim 1, wherein the state of the vehicle comprises at least one of a speed of the vehicle, a heading of the vehicle, and a current environment of the vehicle.

11. A method comprising:

receiving, at a computing system from at least one input-indication sensor, an indication of an input provided to a braking system of a vehicle, wherein the computing system is operating the braking system in an autonomous mode;

receiving, at the computing system from at least one output-indication sensor, an indication of an output of the braking system of the vehicle;

determining, by the computing system, a predicted output value based on the indication of the input, a state of the vehicle, and a wear coefficient indicative of wear associated with the braking system, wherein the state of the vehicle includes at least a speed of the vehicle;

determining whether the predicted output value is within a threshold range of the indication of the output; and

based on determining that the predicted output value is not within the threshold range of the indication of the output, causing, by the computing system, the braking system to perform an alert action that includes at least reducing the speed of the vehicle.