# US 12,179,764 B2 · Method of determining traveling state of vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,764 B2 - Document ID: US12179764B2 - Status: Granted - Kind: B2 - Application number: 17/868,481 - Filed: 2022-07-19 - Published: 2023-02-02 - Granted: 2024-12-31 - Earliest claimed: 2021-08-02 - Assignees: Hyundai Motor Company; Kia Corporation - Applicants: Hyundai Motor Company; Kia Corporation - Inventors: Ji Won Oh; Jeong Soo Eo - Web page: https://patentgrep.com/patent/US12179764B2 ## CPC - B60W 30/18172: {Preventing, or responsive to skidding of wheels} - B60W 40/107: Longitudinal acceleration - B60W 50/00: Details of control systems for road vehicle drive control not related to the control of a particular sub-unit {, e.g. process diagnostic or vehicle driver interfaces} - B60W 2050/0022: {Gains, weighting coefficients or weighting functions} - B60W 2050/0052: {Filtering, filters} - B60W 2510/081: Speed - B60W 2510/083: Torque - B60W 2520/105: Longitudinal acceleration - B60W 2520/26: Wheel slip - B60W 2530/16: Driving resistance - B60W 2552/15: Road slope, i.e. the inclination of a road segment in the longitudinal direction - B60W 2552/35: Road bumpiness, e.g. potholes - B60W 2554/60: Traversable objects, e.g. speed bumps or curbs - Y02T 10/72: Electric energy management in electromobility - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method of determining a traveling state of a vehicle, such as passing over a speed bump, occurrence of wheel slip, or traveling on a slope, is determined in real time to prevent degradations in wheel slip control performance and to avoid unnecessarily malfunctions in a traction control system without compromise of wheel slip control performance. The method includes steps of: determining a torque command of a drive unit to apply torque to a drive wheel in accordance with vehicle driving information collected during traveling of the vehicle; determining an acceleration error in accordance with the determined torque command and information regarding a measured longitudinal acceleration of the vehicle measured by a first sensor; determining an acceleration disturbance rate in accordance with the determined torque command; and determining a current traveling state of the vehicle in accordance with the determined acceleration error and the determined acceleration disturbance rate. ## Claims ### Claim 1 A method for wheel slip reduction control of a vehicle, the method comprising: determining, by a controller, a torque command of a drive unit to apply torque to a drive wheel in accordance with vehicle driving information collected during traveling of the vehicle; determining, by the controller, an acceleration error in accordance with the determined torque command and information regarding a measured longitudinal acceleration of the vehicle measured by a first sensor, the acceleration error being defined by a difference between a reference longitudinal acceleration of the vehicle connected to the torque command and the measured longitudinal acceleration of the vehicle; determining, by the controller, an acceleration disturbance rate in accordance with the determined torque command, the acceleration disturbance rate being defined by a difference between an actual rotational acceleration of the drive unit and a reference rotational acceleration of the drive unit connected to the torque command; determining, by the controller, a current traveling state of the vehicle in accordance with the determined acceleration error and the determined acceleration disturbance rate; and performing, by the controller, a wheel slip reduction control on the basis of information on the determined current traveling state of the vehicle. ### Claim 2 (depends on 1) The method according to claim 1, wherein, in determining the acceleration error, the reference longitudinal acceleration of the vehicle is determined from wheel driving force generated by the drive wheel by the drive unit in response to the torque command, in accordance with the following equation: wheel driving force−rolling resistance−air resistance=vehicle equivalent inertia×reference longitudinal acceleration. ### Claim 3 (depends on 1) The method according to claim 1, wherein, in determining the acceleration error, the acceleration error is estimated by a first observer configured in the controller in accordance with the torque command, the measured longitudinal acceleration of the vehicle, a measured longitudinal velocity of the vehicle measured by a second sensor, equivalent inertia of the vehicle, and a drag acceleration of the vehicle. ### Claim 4 (depends on 3) The method according to claim 3, wherein the acceleration error is determined by the first observer in accordance with the following equation: d dt [ v ^ x , fil v ^ x , tq a ~ ^ tq γ ^ scl ] = [ - L fil 0 0 0 L p ⁢ 1 - L p ⁢ 1 1 T whl I nom ′ L i ⁢ 1 - L i ⁢ 1 0 0 γ ⁢ T . whl ⁢ L i ⁢ 1 - γ ⁢ T . whl ⁢ L i ⁢ 1 0 0 ] [ v ^ x , fil v ^ x , tq a ~ ^ tq γ ^ scl ] + [ L fil ⁢ v x , meas + a meas T whl I nom ′ - a drag 0 0 ] , where Vx,meas is the measured longitudinal velocity of the vehicle, ameas is the measured longitudinal acceleration of the vehicle, {circumflex over (v)}x,fil is a longitudinal velocity of the vehicle filtered after being measured by the second sensor, âfil is a longitudinal acceleration of the vehicle filtered after being measured by the first sensor, Lfil is a filter gain, Twhl is the torque command, I′nom is scaled equivalent inertia of the vehicle, adragg is the drag acceleration of the vehicle, Lp1 is a P gain of the first observer, Li1 is an I gain of the first observer, {circumflex over (γ)}scl is an estimated torque scaled factor, {circumflex over (v)}x,tq is an estimated longitudinal velocity of the vehicle, âtq is an estimated longitudinal acceleration of the vehicle serving as the reference longitudinal acceleration, {tilde over (â)}tq is an estimated acceleration error to be obtained, and γ is an adaptive gain. ### Claim 5 (depends on 1) The method according to claim 1, wherein, in determining the acceleration disturbance rate, an actual rotational acceleration of the drive unit is obtained by differentiating a rotational speed of the drive unit measured by a third sensor, and the reference rotational acceleration of the drive unit is determined using the torque command as a drive unit torque in accordance with the following equation: drive unit torque−rotational resistance torque=equivalent rotational inertia×reference drive unit rotational acceleration. ### Claim 6 (depends on 5) The method according to claim 5, wherein the drive unit comprises a motor driving the vehicle. ### Claim 7 (depends on 1) The method according to claim 1, wherein, in determining the acceleration disturbance rate, the acceleration disturbance rate is determined by the second observer configured in the controller using the measured rotational speed of the drive unit measured by a third sensor and an estimated rotational speed of the drive unit obtained by integrating the reference rotational acceleration of the drive unit determined from the torque command, in accordance with the following equation: {tilde over ({dot over (α)})}mot=Li2(ωmot−{circumflex over (ω)}mot), where ωmot is a measured rotational speed of the drive unit, {circumflex over (ω)}mot is an estimated rotational speed of the drive unit, Lp2 is a P gain of a second observer, and {tilde over ({dot over (a)})}mot is an acceleration disturbance rate to be obtained. ### Claim 8 (depends on 7) The method according to claim 7, wherein the reference rotational acceleration of the drive unit is determined using the torque command as a drive unit torque in accordance with the following equation: drive unit torque−rotational resistance torque=equivalent rotational inertia×reference rotational acceleration of the drive unit. ### Claim 9 (depends on 1) The method according to claim 1, wherein, in determining the acceleration disturbance rate, the acceleration disturbance rate is determined by a second observer configured in the controller in accordance with a measured rotational speed of the drive unit measured by a third sensor and the torque command. ### Claim 10 (depends on 9) The method according to claim 9, wherein the acceleration disturbance rate is determined by the second observer in accordance with the following equations: ω ^ . mot = 1 r g ⁢ T whl + L p ⁢ 2 ( ω mot - ω ^ mot ) + α ~ mot , and {tilde over ({dot over (α)})}mot=Li2(ωmot−{circumflex over (ω)}mot), where ωmot is a measured rotational speed of the drive unit, {circumflex over (ω)}mot is an estimated rotational speed of the drive unit, {tilde over ({dot over (α)})}mot is an acceleration disturbance rate to be obtained, Lp2 is a P gain of the second observer, Li2 is an I gain of the second observer, rg is an effective gear ratio from the drive unit to the drive wheel, and Twhl is the torque command. ### Claim 11 (depends on 1) The method according to claim 1, wherein the drive unit comprises a motor driving the vehicle. ### Claim 12 (depends on 1) The method according to claim 1, wherein, in determining the current traveling state of the vehicle, the current traveling state comprises passing over a height difference portion of a road and a wheel slip occurrence, and the current traveling state is determined by at least one of the passing over the height difference portion of the road or the wheel slip occurrence. ### Claim 13 (depends on 12) The method according to claim 12, wherein the height difference portion of the road comprises one of a speed bump, a raised portion, a pothole, and a recess having a concaved shape present in the road that a tire of the vehicle touches. ### Claim 14 (depends on 12) The method according to claim 12, further comprising calculating, by the controller, an acceleration disturbance by integrating the determined acceleration disturbance rate, wherein, when the current traveling state of the vehicle is determined to be neither the passing over the height difference portion of the road nor the wheel slip occurrence, the controller converts the size of the calculated acceleration disturbance into a road slope value using a set equation, and when the current traveling state of the vehicle is determined to be at least one of the passing over the height difference portion of the road or the wheel slip occurrence, the controller stops calculating the road slope value and holds a road slope value calculated directly before. ### Claim 15 (depends on 12) The method according to claim 12, wherein the controller divides the passing over the height difference portion of the road and the wheel slip occurrence from each other, the controller is configured such that, when the current traveling state of the vehicle is determined to be the passing over the height difference portion of the road but not the wheel slip occurrence, the controller does not perform wheel slip reduction control, and when the current traveling state of the vehicle is determined to be the wheel slip occurrence but not the passing over the height difference portion of the road, the controller performs the wheel slip reduction control. ### Claim 16 (depends on 12) The method according to claim 12, wherein the controller determines an upper threshold value and a lower threshold value variable in real time according to the acceleration disturbance rate, using the determined acceleration disturbance rate, and when the determined acceleration error is a value out of a range between the determined upper threshold value and the determined lower threshold value, the controller determines the current traveling state of the vehicle to be the passing over the height difference portion of the road. ### Claim 17 (depends on 16) The method according to claim 16, wherein the controller determines the upper threshold value and the lower threshold value by obtaining an envelope value of an envelope function or a peak value of a peak-peak detection function, with the determined acceleration disturbance rate being an input. ### Claim 18 (depends on 12) The method according to claim 12, further comprising calculating, by the controller, an acceleration disturbance in real time by integrating the determined acceleration disturbance rate, wherein the controller determines an upper threshold value and a lower threshold value variable in real time using the determined acceleration disturbance rate and the determined acceleration disturbance, and when the determined acceleration error is a value out of a range between the upper threshold value and the lower threshold value, the controller determines the current traveling state of the vehicle to be the passing over the height difference portion of the road. ### Claim 19 (depends on 18) The method according to claim 18, wherein the controller determines the upper threshold value and the lower threshold value by obtaining an envelope value of an envelope function or a peak value of a peak-peak detection function, with a value obtained by applying predetermined weights to the determined acceleration disturbance rate and the determined acceleration disturbance, respectively, and summing the weighted acceleration disturbance rate and the weighted acceleration disturbance being an input. ### Claim 20 (depends on 12) The method according to claim 12, wherein, when the determined acceleration disturbance rate exceeds a set threshold value for determining the wheel slip occurrence, the controller determines the current traveling state of the vehicle to be the wheel slip occurrence.