Patent Issued for Light Impact Detection For Vehicle Using Low Computation Overhead (USPTO 10,417,913)

2019 SEP 30 (NewsRx) -- By a News Reporter-Staff News Editor at Transportation Daily News -- A patent by the inventors Panigrahi, Smruti R. (Farmington Hills, MI); Lu, Jianbo (Northville, MI); Hong, Sanghyun (Canton, MI); Scott, Jonathan (Chelmsford, GB); Filev, Dimitar P. (Novi, MI), filed on March 15, 2016, was published online on September 30, 2019, according to news reporting originating from Alexandria, Virginia, by NewsRx correspondents.

Patent number 10,417,913 is assigned to Ford Global Technologies LLC (Dearborn, Michigan, United States).

The following quote was obtained by the news editors from the background information supplied by the inventors: “The present invention relates in general to automotive crash detection, and, more specifically, to detecting the occurrence of a light to moderate impact event having a severity less than one that should trigger deployment of a passive restraint such as an air bag.

“Vehicle crash detection is a well-developed technology in the context of passive restraint systems which deploy during a crash in order to protect the vehicle occupants. Specialized sensors and robust detection algorithms provide a high reliability in detecting the onset of a crash that has a sufficient severity to automatically activate a passive restraint.

“A typical crash sensing system may be comprised of an array of accelerometers, for example. Longitudinal and lateral acceleration sensor signals from the accelerometers can be generated within or communicated to a Restraints Control Module (RCM) which makes a deployment decision. Accelerometers mounted in the RCM have detection ranges from about -50 g to about +50 g. Satellite accelerometers remotely located in the front and sides of the vehicle typically have ranges from about -250 g tom about +250 g. Light to moderate impacts involving lower levels of acceleration cannot be reliably detected using the existing accelerometers. However, there would be benefits to having an ability to detect light impacts, i.e., when the impact severity is less than what the RCM module uses to initiate a restraint deployment.

“Although light impacts between vehicles do not cause significant damage to the driver or passenger directly, they could begin a chain of post impact events which can lead to undesired outcomes such as further impacts or rollovers. Therefore, the detection and recording of occurrences of light impact collisions may of interest to vehicle owners, vehicle fleet operators, law-enforcement personnel, and insurance providers. This invention discloses techniques and systems for detecting light impacts to enable many different kinds of reactions such as modified vehicle control, the real-time alerting of third parties (e.g., insurance, fleet, and law enforcement agencies), and the recording/storage of incident information in the vehicle for later use by fleet operators and law enforcement for accident reconstruction.

“Known methods for detecting impacts in restraint systems may not be apt for detecting light impacts because they typically require different sensors that may not be well suited to detection of light crashes and they may require significant computing resources and/or data transmission. A typical automotive electronics architecture comprises a plurality of distributed controller modules and sensor devices connected as nodes in a multiplex communication network. In view of the ultimate uses to which the detection of a light impact would be put, an optimal implementation would typically locate the light-impact detection function in a controller module other than a restraints control module (e.g., in a body control module or a powertrain control module) where computing resources may be in short supply. Therefore, it would be desirable to achieve reliable detection of light impact events using low computing overhead while consuming a minimal amount of data traffic over a multiplex controller network.”

In addition to the background information obtained for this patent, NewsRx journalists also obtained the inventors’ summary information for this patent: “Vehicle longitudinal and lateral acceleration, yaw rate, and vehicle speed which are typically being shared between various modules over a high-speed CAN bus are used in the light impact detection algorithm. A body control module (BCM) provides a preferred location for implementing the light impact detection. Sensor signals from accelerometers of the type installed as part of a vehicle dynamics system (e.g., a powertrain controller or a traction control or braking system) have ranges typically between about -10 g to about +10 g, which is enough to detect the light impacts. Vehicle velocity can be derived from wheel speed or from a transmission-based vehicle speed. A fused vehicle speed based on combining vehicle speed estimations from different vehicle systems may be desirable. Vehicle yaw rate (likewise available over a CAN bus from various motion sensors) is monitored to detect unusual or undesired angular velocity and acceleration that would be associated with light-impact conditions. Motion sensor information on roll rate can also be monitored/recorded in order to report the dynamic state in case of a roll-over of the vehicle. A driver’s control intent such as throttle position, driver brake pedal travel, driver steering angle, etc. can also be recorded from the high-speed CAN bus to obtain an insight into driver behavior before, during, and after a light impact.

“In one aspect of the invention, a method is provided for detecting a light impact against a vehicle. A measured acceleration and a measured yaw rate are compared to respective baseline thresholds in a baseline state. When the acceleration is above the respective baseline threshold, then a center-of-gravity to impact distance is determined according to a mass of the vehicle, a moment of inertia of the vehicle, the measured acceleration of the vehicle, and the measured yaw rate of the vehicle. When the determined distance is less than a vehicle edge distance, then an impact-suspected state is entered if at least one of the acceleration and yaw rate is above the respective baseline threshold for a first predetermined duration. In the impact-suspected state, a plurality of vehicle dynamic behaviors are monitored for confirming occurrence of the light impact, wherein the method returns to the baseline state if the acceleration and yaw rate fail to remain above the respective baseline threshold or if the calculated distance fails to remain less than the vehicle edge distance. A light impact is detected when at least one of the behaviors confirms the occurrence.”

The claims supplied by the inventors are:

“What is claimed is:

“1. A method of detecting a light impact against a vehicle, comprising: (a) comparing a measured acceleration and a measured yaw rate to respective baseline thresholds in a baseline state; (b) when the acceleration is above the respective baseline threshold, then determining a center-of-gravity to impact distance according to a mass of the vehicle, a moment of inertia of the vehicle, the measured acceleration of the vehicle, and the measured yaw rate of the vehicle; © when the determined distance is less than a vehicle edge distance, then entering an impact-suspected state when at least one of the acceleration and yaw rate is above the respective baseline threshold for a first predetermined duration; (d) in the impact-suspected state, monitoring a plurality of vehicle dynamic behaviors for confirming occurrence of the light impact, wherein the method returns to the baseline state if the acceleration and yaw rate fail to remain above the respective baseline threshold or if the determined distance fails to remain less than the vehicle edge distance; and (e) detecting the light impact when at least one of the behaviors confirms the occurrence.

“2. The method of claim 1 wherein the behaviors include: confirming the light impact when at least one of the acceleration and yaw rate remains above the respective baseline threshold for a second predetermined duration greater than the first predetermined duration.

“3. The method of claim 1 wherein the behaviors include: determining a difference in vehicle velocities measured at two different times; and confirming the light impact when the difference is greater than a predetermined difference.

“4. The method of claim 3 wherein the vehicle velocities are longitudinal velocities.

“5. The method of claim 3 wherein the vehicle velocities are lateral velocities.

“6. The method of claim 1 wherein the behaviors include: determining a side slip ratio for each of a front axle and a rear axle of the vehicle; and confirming the light impact when at least one of the side slip ratios is greater than a predetermined side slip ratio.

“7. The method of claim 1 wherein the behaviors include: confirming the light impact when the yaw rate exceeds a predetermined maximum angular velocity.

“8. The method of claim 1 wherein the behaviors include: determining a lane departure acceleration in response to the yaw rate and a longitudinal velocity of the vehicle; and confirming the light impact when the lane departure acceleration exceeds a lane departure threshold.

“9. The method of claim 1 wherein the center-of-gravity to impact distance is further determined according to a recursive least squares fit.

“10. The method of claim 1 wherein the measured acceleration is comprised of a total acceleration derived from measured longitudinal acceleration and measured lateral acceleration.

“11. A vehicle apparatus comprising: vehicle dynamics sensors measuring vehicle acceleration and yaw; a controller network with at least one controller module communicatively coupled to the dynamics sensors, wherein the controller network: a) compares a measured acceleration and a measured yaw rate to respective baseline thresholds in a baseline state; (b) if the acceleration is above the respective baseline threshold, determines a center-of-gravity to impact distance according to a mass of the vehicle, a moment of inertia of the vehicle, the measured acceleration of the vehicle, and the measured yaw rate of the vehicle; © if the determined distance is less than a vehicle edge distance, then enters an impact-suspected state when at least one of the acceleration and yaw rate is above the respective baseline threshold for a first predetermined duration; (d) in the impact-suspected state, monitors a plurality of vehicle dynamic behaviors for confirming occurrence of the light impact, wherein the controller network returns to the baseline state if the measured acceleration and yaw rate fail to remain above the respective baseline threshold or if the determined distance fails to remain less than the vehicle edge distance; and (e) detects the light impact when at least one of the behaviors confirms the occurrence.

“12. The vehicle apparatus of claim 11 further comprising non-volatile storage for recording data associated with the confirmed light impact including a time, a date, and a location.

“13. The vehicle apparatus of claim 11 further including a passive restraint system triggered in response to impacts having a severity greater than a severity of the light impact, wherein the passive restraint system performs an impact detection function that is adjusted in response to confirmation of a light impact.

“14. The vehicle apparatus of claim 11 wherein the behaviors include: confirming the light impact when at least one of the acceleration and yaw rate remaining above the respective baseline threshold for a second predetermined duration greater than the first predetermined duration.

“15. The vehicle apparatus of claim 11 wherein the behaviors include: determining a difference in vehicle velocities measured at two different times; and confirming the light impact when the difference is greater than a predetermined difference.

“16. The vehicle apparatus of claim 11 wherein the behaviors include: determining a side slip ratio for each of a front axle and a rear axle of the vehicle; and confirming the light impact when at least one of the side slip ratios is greater than a predetermined side slip ratio.

“17. The vehicle apparatus of claim 11 wherein the behaviors include: confirming the light impact when the yaw rate exceeds a predetermined maximum angular velocity.

“18. The vehicle apparatus of claim 11 wherein the behaviors include: determining a lane departure acceleration in response to the yaw rate and a longitudinal velocity of the vehicle; and confirming the light impact when the lane departure acceleration exceeds a lane departure threshold.

“19. The vehicle apparatus of claim 11 wherein the center-of-gravity to impact distance is calculated according to a recursive least squares fit.

“20. The vehicle apparatus of claim 11 wherein the measured acceleration is comprised of a total acceleration derived from measured longitudinal acceleration and measured lateral acceleration.”

URL and more information on this patent, see: Panigrahi, Smruti R.; Lu, Jianbo; Hong, Sanghyun; Scott, Jonathan; Filev, Dimitar P. Light Impact Detection For Vehicle Using Low Computation Overhead. U.S. Patent Number 10,417,913, filed March 15, 2016, and published online on September 30, 2019. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=10,417,913.PN.&OS=PN/10,417,913RS=PN/10,417,913

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