# US 12,110,024 B2 · Consideration of acceleration lag in lead vehicle to enhance host vehicle operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,024 B2 - Document ID: US12110024B2 - Status: Granted - Kind: B2 - Application number: 17/136,580 - Filed: 2020-12-29 - Published: 2022-06-30 - Granted: 2024-10-08 - Earliest claimed: 2020-12-29 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Vivek Vijaya Kumar; Kausalya Singuru; Kevin A. O'Dea; Carl P. Darukhanavala - Web page: https://patentgrep.com/patent/US12110024B2 ## CPC - B60W 30/162: {Speed limiting therefor} - B60W 30/165: Automatically following the path of a preceding lead vehicle, e.g. "electronic tow-bar" - B60W 60/001: {Planning or execution of driving tasks} - B60W 2420/403: Image sensing, e.g. optical camera - B60W 2420/408: Radar; Laser, e.g. lidar - B60W 2554/404: Characteristics - B60W 2554/802: Longitudinal distance - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT ## Abstract A method includes obtaining information about a lead vehicle. The lead vehicle is traveling directly ahead of the host vehicle and the information includes velocity of the lead vehicle and a gap g between the host vehicle and the lead vehicle. Based on detecting a change in the velocity of the lead vehicle in the information, a corresponding desired acceleration is computed for the host vehicle using perceived acceleration of the lead vehicle to maintain the gap g within a specified range of gap values. The perceived acceleration of the lead vehicle is based on the change in the velocity indicated by the information. Based on a check of parameters involved in the computing the corresponding desired acceleration, a modified desired acceleration is computed for the host vehicle using a lag for the lead vehicle that results in an intended acceleration of the lead vehicle differing from the perceived acceleration. ## Claims ### Claim 1 A method for operating a host vehicle, comprising: obtaining, by processing circuitry of the host vehicle, a velocity of a lead vehicle and a gap g between the host vehicle and the lead vehicle, wherein the lead vehicle is traveling ahead of the host vehicle; computing a perceived acceleration of the lead vehicle based on a change in the velocity of the lead vehicle, wherein the perceived acceleration of the lead vehicle differs from an intended acceleration of the lead vehicle commanded by a driver or controller of the lead vehicle by a lag between the intended acceleration and a response of the lead vehicle to the intended acceleration; computing, using the processing circuitry, a corresponding desired acceleration for the host vehicle using the perceived acceleration of the lead vehicle to maintain the gap g within a specified range of gap values; computing, using the processing circuitry, a modified desired acceleration for the host vehicle using the desired acceleration for the host vehicle and the lag for the lead vehicle; controlling the host vehicle by implementing the modified desired acceleration at the host vehicle to maintain the gap g; and updating the lag for the lead vehicle based on a comparison of the actual gap resulting from implementing the modified desired acceleration and the gap g. ### Claim 2 (depends on 1) The method according to claim 1, further comprising obtaining the measured velocity of the lead vehicle using a sensor, and the sensor includes a radar system, a lidar system, or a camera. ### Claim 3 (depends on 1) The method according to claim 1, wherein the computing the corresponding desired acceleration for the host vehicle includes determining a desired gap g* as: g * = g 0 + max ⁡ [ 0 , ( ϑ H ⁢ T + ( ϑ H ⁢ Δϑ 2 ⁢ a H ⁢ b ) ) ] , where g0 is a set minimum gap value, ϑH a current velocity of the host vehicle, Tis a known constant related to a time associated with a safe gap, Δϑ is a difference between a current velocity ϑL of the lead vehicle and the current velocity ϑH of the host vehicle, αH is a current acceleration of the host vehicle, and b is a known constant that limits deceleration. ### Claim 4 (depends on 3) The method according to claim 3, further comprising computing the modified desired acceleration when the desired gap g* is outside the specified range of gap values. ### Claim 5 (depends on 3) The method according to claim 3, wherein the computing the corresponding desired acceleration for the host vehicle includes determining the desired acceleration {dot over (ϑ)}H (t) for the host vehicle as: ϑ . H ⁡ ( t ) = a H ⁡ ( 1 - ( ϑ H ϑ Hf ) δ ) - a H ⁡ ( ( g * ⁡ ( ϑ H ⁢ Δϑ ) g ) 2 ) , where ϑHf is a final velocity of the host vehicle needed to achieve the desired gap g*, and g is a current gap. ### Claim 6 (depends on 5) The method according to claim 5, further comprising determining if a difference between a current acceleration of the host vehicle and the corresponding desired acceleration is within a specified range. ### Claim 7 (depends on 5) The method according to claim 5, further comprising determining a vehicle type for the lead vehicle and computing the modified desired acceleration of the host vehicle using: αest={dot over (ϑ)}H(t)(1−e(t-φ)τ), where τ is a lag time constant for the vehicle type and φ is a delay constant for the vehicle type and τ and φ are obtained from a look-up table. ### Claim 8 (depends on 7) The method according to claim 7, wherein the modified desired acceleration of the host vehicle is computed by adding one or more model-based factors to αest. ### Claim 9 (depends on 8) The method according to claim 8, wherein the model-based factors include an acceleration factor statistical model of slowdown of the lead vehicle and a smoothness factor. ### Claim 10 (depends on 7) The method according to claim 7, further comprising updating the look-up table for the type of the lead vehicle based on a result of the implementing the corresponding desired acceleration at the host vehicle. ### Claim 11 A system in a host vehicle, the system comprising: one or more sensors configured to measure a velocity of a lead vehicle and a gap g between the host vehicle and the lead vehicle ahead of the host vehicle; and a controller configured to: compute a perceived acceleration of the lead vehicle based on detecting a change in the velocity of the lead vehicle, wherein the perceived acceleration of the lead vehicle differs from an intended acceleration of the lead vehicle commanded by a driver or controller of the lead vehicle by a lag between the intended acceleration and a response of the lead vehicle to the intended acceleration; compute a corresponding desired acceleration for the host vehicle using the perceived acceleration of the lead vehicle to maintain the gap g within a specified range of gap values; compute, a modified desired acceleration for the host vehicle using the desired acceleration for the host vehicle and the lag for the lead vehicle; control the host vehicle to implement the modified desired acceleration at the host vehicle to maintain the gap g; and update the lag for the lead vehicle based on a comparison of the actual gap resulting from implementing the modified desired acceleration and the gap g. ### Claim 12 (depends on 11) The system according to claim 11, wherein the one or more sensors include a radar system, a lidar system, or a camera. ### Claim 13 (depends on 11) The system according to claim 11, wherein the controller is configured to compute the corresponding desired acceleration for the host vehicle by determining a desired gap g* as: g * = g 0 + max ⁡ [ 0 , ( ϑ H ⁢ T + ( ϑ H ⁢ Δϑ 2 ⁢ a H ⁢ b ) ) ] , where g0 is a set minimum gap value, ϑH is a current velocity of the host vehicle, T is a known constant related to a time associated with a safe gap, Δϑ is a difference between a current velocity ϑL of the lead vehicle and the current velocity ϑH of the host vehicle, αH is a current acceleration of the host vehicle, and b is a known constant that limits deceleration. ### Claim 14 (depends on 13) The system according to claim 13, wherein the controller is configured to compute the modified desired acceleration when the desired gap g* is outside the specified range of gap values. ### Claim 15 (depends on 13) The system according to claim 13, wherein the controller is configured to compute the corresponding desired acceleration for the host vehicle by determining the desired acceleration {dot over (ϑ)}H(t) for the host vehicle as: ϑ . H ⁡ ( t ) = a H ⁡ ( 1 - ( ϑ H ϑ Hf ) δ ) - a H ⁡ ( ( g * ⁡ ( ϑ H ⁢ Δϑ ) g ) 2 ) , where ϑHf is a final velocity of the host vehicle needed to achieve the desired gap g*, and g is a current gap. ### Claim 16 (depends on 15) The system according to claim 15, wherein the controller is configured to determine if a difference between a current acceleration of the host vehicle and the corresponding desired acceleration is within a specified range. ### Claim 17 (depends on 15) The system according to claim 15, wherein the controller is configured to determine a vehicle type for the lead vehicle and compute the modified desired acceleration of the host vehicle as: αest={dot over (ϑ)}H(t)(1−e(t-φ)τ), where τ is a lag time constant for the vehicle type and φ is a delay constant for the vehicle type and τ and φ are obtained from a look-up table. ### Claim 18 (depends on 17) The system according to claim 17, wherein the controller is configured to compute the modified desired acceleration of the host vehicle by adding one or more model-based factors. ### Claim 19 (depends on 18) The system according to claim 18, wherein the model-based factors include an acceleration factor statistical model of slowdown of the lead vehicle and a smoothness factor. ### Claim 20 (depends on 17) The system according to claim 17, wherein the controller is configured to update the look-up table for the type of the lead vehicle based on a result of implementing the new corresponding desired acceleration for the host vehicle.