# US 8,771,140 B2 · Machine control system utilizing inertial yaw sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,140 B2 - Document ID: US8771140B2 - Status: Granted - Kind: B2 - Application number: 13/457,186 - Filed: 2012-04-26 - Published: 2012-08-23 - Granted: 2014-07-08 - Earliest claimed: 2008-12-22 - Assignees: Caterpillar Inc. - Applicants: Gerry O. McCann; Yun Liu; Keith F. Harvey - Inventors: Gerry O. McCann; Yun Liu; Keith F. Harvey - Web page: https://patentgrep.com/patent/US8771140B2 ## CPC - B60K 17/20: {in which the differential movement is limited} - B60K 17/34: for driving both front and rear wheels, e.g. four wheel drive vehicles - B60K 23/04: for differential gearing - B60W 10/119: including control of all-wheel-driveline means, e.g. transfer gears or clutches for dividing torque between front and rear axle (B60W10/14 takes precedence) - B60W 10/14: Central differentials for dividing torque between front and rear axles - B60W 10/16: Axle differentials, e.g. for dividing torque between left and right wheels - B60W 30/045: Improving turning performance - B60W 30/18145: {Cornering} - F16D 48/06: Control by electric or electronic means, e.g. of fluid pressure - B60W 2520/14: Yaw - B60W 2520/22: Articulation angle, e.g. between tractor and trailer - B60W 2520/28: Wheel speed - B60W 2720/10: Longitudinal speed - B60W 2720/28: Wheel speed - B60W 2720/403: between front and rear axle - B60W 2720/406: between left and right wheel - B60Y 2200/14: Trucks; Load vehicles, Busses - B60Y 2200/147: Trailers, e.g. full trailers or caravans - B60Y 2200/148: Semi-trailers, articulated vehicles - B60Y 2200/20: Off-Road Vehicles - B60Y 2200/222: Harvesters - F16D 2500/10431: 4WD Clutch dividing power between the front and the rear axle - F16D 2500/1112: Heavy vehicle - F16D 2500/3108: Vehicle speed - F16D 2500/3118: Slip of vehicle wheels - F16D 2500/70668: Signal filtering - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - 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 - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY ## Abstract An electronic traction optimization system includes a control unit adapted to produce a corner speed estimate signal for each wheel of a machine, produce an ideal target speed signal for each wheel having a value at least partially responsive to the corner speed estimate signals, produces a practical target speed signal for each wheel, generates an actual target speed signal having a value responsive to a comparison of the ideal target speed signal and the practical target speed signal for each wheel. The control unit compares each actual target speed signal to an associated wheel speed signal to obtain a wheel speed error signal for each wheel and converts each wheel speed error signal to a clutch control signal, wherein each differential clutch actuator is responsive to an associated clutch control signal. ## Claims ### Claim 1 A method of operating a machine having a frame, a drive train differential gear set connecting a first pair of traction devices and a second pair of traction devices, comprising using a control unit for: sensing a first speed of at least one traction device of the first pair of traction devices with a first speed sensor; sensing a second speed of at least one traction device of the second pair of traction devices with a second speed sensor; determining a first time-based average speed indicative of the speed of the first pair of traction devices and a second time-based average speed indicative of the speed of the second pair of traction devices; and selectively engaging a clutch assembly associated with the drive-train differential gear set to engage the differential gear set when: the first sensed speed oscillates about the first time-based average speed of the first pair of traction devices, or the second sensed speed oscillates about the second time-based average speed of the second pair of traction devices. ### Claim 2 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when both: the first sensed speed oscillates with respect to the first time-based average speed of the first pair of traction devices, and the second sensed speed oscillates with respect to the second time-based average speed of the second pair of traction devices. ### Claim 3 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates about the first time-based average speed of the first pair of traction devices. ### Claim 4 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the second sensed speed oscillates about the second time-based average speed of the second pair of traction devices. ### Claim 5 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when: the first sensed speed oscillates about the first time-based averaged speed of the first pair of traction devices; the second sensed speed oscillates about the second time-based averaged speed of the second pair of traction devices; and the oscillating first sensed speed oscillates out of phase about the oscillating second sensed speed. ### Claim 6 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when: the first sensed speed oscillates about the first time-based averaged speed of the first pair of traction devices; the second sensed speed oscillates about the second time-based averaged speed of the second pair of traction devices; and the oscillating first sensed speed oscillates 180° out of phase about the oscillating second sensed speed. ### Claim 7 (depends on 1) The method of claim 1, wherein the first time-based averaged speed of the first pair of traction devices is different than the second time-based averaged speed of the second pair of traction devices. ### Claim 8 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates about the first time-based averaged speed of the first pair of traction devices at 3 Hz. ### Claim 9 (depends on 1) The method of claim 1, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates about the first time-based averaged speed of the first pair of traction devices at 2 Hz. ### Claim 10 A method of operating a machine having a frame, a drive train differential gear set connecting a first pair of traction devices and a second pair of traction devices, comprising using a control unit for: sensing a first speed of at least one traction device of the first pair of traction devices with a first speed sensor; sensing a second speed of at least one traction device of the second pair of traction devices with a second speed sensor; determining a first time-based average speed indicative of the speed of the first pair of traction devices and a second time-based average speed indicative of the speed of the second pair of traction devices; and selectively engaging a clutch assembly associated with the drive-train differential gear set to engage the differential gear set when: the first sensed speed oscillates about the first time-based average speed of the first pair of traction devices, the second sensed speed oscillates about the second time-based average speed of the second pair of traction devices, and the oscillating first sensed speed oscillates out of phase with respect to the oscillating second sensed speed. ### Claim 11 (depends on 10) The method of claim 10, wherein the oscillating first sensed speed is 180° out of phase with respect to the oscillating second sensed speed. ### Claim 12 (depends on 10) The method of claim 10, wherein the first time-based averaged speed of the first pair of traction devices is different than the second time-based averaged speed of the second pair of traction devices. ### Claim 13 (depends on 10) The method of claim 10, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates with respect to the first time-based averaged speed of the first pair of traction devices at 3 Hz. ### Claim 14 (depends on 10) The method of claim 10, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates with respect to the first time-based averaged speed of the first pair of traction devices at 2 Hz. ### Claim 15 A method of operating an articulated truck having a frame, a front cab supported relative to an operating surface by a first pair of traction devices, a dump body supported relative to the operating surface by a second pair of traction devices, an articulation joint interconnecting the front cab and the dump body, a drive train differential gear set connecting the first pair of traction devices and a second pair of traction devices, comprising using a control unit for: sensing a first speed of at least one traction device of the first pair of traction devices with a first speed sensor; sensing a second speed of at least one traction device of the second pair of traction devices with a second speed sensor; determining a first time-based average speed indicative of the speed of the first pair of traction devices and a second time-based average speed indicative of the speed of the second pair of traction devices; and selectively engaging a clutch assembly associated with the drive-train differential gear set to engage the differential gear set when: the first sensed speed oscillates about the first time-based average speed of the first pair of traction devices, the second sensed speed oscillates about the second time-based average speed of the second pair of traction devices, and the oscillating first sensed speed oscillates out of phase with respect to the oscillating second sensed speed. ### Claim 16 (depends on 15) The method of claim 15, wherein the oscillating first sensed speed is 180° out of phase with respect to the oscillating second sensed speed. ### Claim 17 (depends on 15) The method of claim 15, wherein the first time-based averaged speed of the first pair of traction devices is different than the second time-based averaged speed of the second pair of traction devices. ### Claim 18 (depends on 15) The method of claim 15, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates with respect to the first time-based averaged speed of the first pair of traction devices at 3 Hz. ### Claim 19 (depends on 15) The method of claim 15, further including selectively engaging the clutch assembly associated with the drive-train differential gear set when the first sensed speed oscillates with respect to the first time-based averaged speed of the first pair of traction devices at 2 Hz. ### Claim 20 (depends on 15) The method of claim 15, wherein the articulation joint is disposed between the first pair of traction devices and the second pair of traction devices to enable the front cab to articulate relative to the dump body. ### Claim 21 A method of operating a machine having a frame, a drive train differential gear set connecting a first pair of traction devices and a second pair of traction devices, comprising using a control unit for: sensing a first speed of at least one traction device of the first pair of traction devices with a first speed sensor; sensing a second speed of at least one traction device of the second pair of traction devices with a second speed sensor; and selectively engaging a clutch assembly associated with the drive-train differential gear set to engage the differential gear set when: the first sensed speed oscillates about a first time-based average speed of the first pair of traction devices, or the second sensed speed oscillates about a second time-based average speed of the second pair of traction devices.