# US 2021/0171014 A1 · System for controlling an engine disconnect clutch in a hybrid vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0171014 A1 - Document ID: US20210171014A1 - Status: Published application - Kind: A1 - Application number: 16/706,022 - Filed: 2019-12-06 - Published: 2021-06-10 - Earliest claimed: 2019-12-06 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Corey James Blue; Minku Lee; Scott James Thompson; Bradley Dean Riedle - Web page: https://patentgrep.com/patent/US20210171014A1 ## CPC - B60K 6/48: Parallel type - B60W 20/40: Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers {(power-up or power-down of the driveline B60W30/192)} - B60W 10/02: including control of driveline clutches - B60W 10/023: {Fluid clutches} - B60W 10/026: {of lock-up clutches} - B60W 10/06: including control of combustion engines - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - B60W 10/11: Stepped gearings - B60W 10/30: including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps - B60K 2006/4825: {Electric machine connected or connectable to gearbox input shaft} - B60W 2510/06: Combustion engines, Gas turbines - B60W 2510/0638: Engine speed - B60W 2510/081: Speed - B60W 2710/021: Clutch engagement state - B60W 2710/022: Clutch actuator position - B60W 2710/024: of torque converter lock-up clutch - B60W 2710/30: Auxiliary equipments - Y02T 10/62: Hybrid vehicles - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A vehicle includes an engine having a crankshaft, an electric machine having a rotor, a disconnect clutch having an input secured to the crankshaft and an output secured to the rotor, a hydraulic pump mechanically powered via rotation of the rotor and configured to supply hydraulic fluid to the actuate the disconnect clutch, a torque converter having an impeller secured to the rotor, and controller. The controller is programmed to, responsive to a speed of the impeller decreasing to less than a first threshold, which is indicative of a subsequent shutdown of the hydraulic pump, and responsive to the disconnect clutch being open while the engine is shut down, advance the disconnect clutch to a touch point where opposing sides of disconnect clutch make contact but substantially zero power is transferred between the engine and the electric machine. ## Claims ### Claim 1 A vehicle comprising: an engine and an electric machine each configured to deliver power to at least one drive wheel; a disconnect clutch disposed between the engine and the electric machine; a step-ratio transmission disposed between the electric machine and the at least one drive wheel; a torque converter having an impeller and disposed between the electric machine and the step-ratio transmission; a primary hydraulic pump mechanically powered via rotation of electric machine and configured to supply hydraulic fluid to actuate the disconnect clutch and a plurality of clutches within the step-ratio transmission; and a controller programmed to, responsive to a speed of the impeller decreasing to less than a first threshold, which is indicative of a subsequent shutdown of the hydraulic pump, and responsive to the disconnect clutch being open while the engine is shut down, operate the primary hydraulic pump to advance the disconnect clutch to a touch point where opposing sides of disconnect clutch make contact but substantially zero power is transferred between the engine and the electric machine. ### Claim 2 (depends on 1) The vehicle of claim 1, wherein the controller is further programmed to, responsive to the speed of the impeller increasing to greater than a second threshold while the disconnect clutch is at the touch point and the engine is shut down, retract and open the disconnect clutch. ### Claim 3 (depends on 2) The vehicle of claim 2, wherein the controller is further programmed to, responsive to the speed of the impeller increasing to greater than the first threshold but less than the second threshold while the disconnect clutch is at the touch point and the engine is shut down, maintain the position of the disconnect clutch at the touch point. ### Claim 4 (depends on 2) The vehicle of claim 2, wherein the second threshold is greater than the first threshold. ### Claim 5 (depends on 2) The vehicle of claim 2, wherein the controller is further programmed to, responsive to receiving a disconnect clutch fault while the disconnect clutch is at the touch point, the engine is shut down, and the impeller speed is less than the second threshold, retract and open the disconnect clutch. ### Claim 6 (depends on 2) The vehicle of claim 2, wherein the controller is further programmed to, responsive to the expiration of a timer after advancing the disconnect clutch to the touch point while the impeller speed remains below the second threshold, retract and open the disconnect clutch. ### Claim 7 (depends on 1) The vehicle of claim 1 further comprising a starter motor configured to start the engine, wherein the controller is further programmed to, responsive to an engine start via the starter motor while the disconnect clutch is at the touch point, operate the electric machine to increase the speed of the impeller to greater than the first threshold and subsequently operate the primary hydraulic pump to advance and close the disconnect clutch to transfer power between the engine and the electric machine. ### Claim 8 (depends on 1) The vehicle of claim 1 further comprising an electrically powered secondary hydraulic pump that is configured to supply hydraulic fluid to actuate the disconnect clutch, wherein the controller is further programmed to, responsive to a command to start the engine via the electric machine while the disconnect clutch is at the touch point and impeller speed is below the first threshold, operate the secondary hydraulic pump to further advance and close the disconnect clutch to transfer power between the engine and the electric machine. ### Claim 9 A vehicle comprising: an engine having a crankshaft; an electric machine having a rotor; a disconnect clutch having an input secured to the crankshaft and an output secured to the rotor; a hydraulic pump mechanically powered via rotation of the rotor and configured to supply hydraulic fluid to actuate the disconnect clutch; a torque converter having an impeller secured to the rotor, and a controller programmed to, responsive to a speed of the impeller decreasing to less than a first threshold, which is indicative of a subsequent shutdown of the hydraulic pump, and responsive to the disconnect clutch being open while the engine is shut down, advance the disconnect clutch to a touch point where opposing sides of disconnect clutch make contact but substantially zero power is transferred between the engine and the electric machine. ### Claim 10 (depends on 9) The vehicle of claim 9, wherein the controller is further programmed to, responsive to the speed of the impeller increasing to greater than a second threshold while the disconnect clutch is at the touch point and the engine is shut down, retract and open the disconnect clutch. ### Claim 11 (depends on 10) The vehicle of claim 10, wherein the controller is further programmed to, responsive to the speed of the impeller increasing to greater than the first threshold but less than the second threshold while the disconnect clutch is at the touch point and the engine is shut down, maintain the position of the disconnect clutch at the touch point. ### Claim 12 (depends on 10) The vehicle of claim 10, wherein the second threshold is greater than the first threshold. ### Claim 13 (depends on 10) The vehicle of claim 10, wherein the controller is further programmed to, responsive to receiving a disconnect clutch fault while the disconnect clutch is at the touch point, the engine is shut down, and the impeller speed is less than the second threshold, retract and open the disconnect clutch. ### Claim 14 (depends on 10) The vehicle of claim 10, wherein the controller is further programmed to, responsive to the expiration of a timer after advancing the disconnect clutch to the touch point while the impeller speed remains below the second threshold, retract and open the disconnect clutch. ### Claim 15 A vehicle comprising: a powertrain having an engine and an electric machine each configured to generate power; a disconnect clutch disposed between the engine and electric machine; a hydraulic pump mechanically powered via rotation of the electric machine and configured to supply hydraulic fluid to actuate the disconnect clutch; and a controller programmed to, responsive to a speed of a rotor of the electric machine decreasing to less than a first threshold, which is indicative of a subsequent shutdown of the hydraulic pump, and responsive to the disconnect clutch being open while the engine is shut down, advance the disconnect clutch to a touch point where opposing sides of disconnect clutch make contact but substantially zero power is transferred between the engine and the electric machine. ### Claim 16 (depends on 15) The vehicle of claim 15, wherein the controller is further programmed to, responsive to the speed of the rotor increasing to greater than a second threshold while the disconnect clutch is at the touch point and the engine is shut down, retract and open the disconnect clutch. ### Claim 17 (depends on 16) The vehicle of claim 16, wherein the controller is further programmed to, responsive to the speed of the rotor increasing to greater than the first threshold but less than the second threshold while the disconnect clutch is at the touch point and the engine is shut down, maintain the position of the disconnect clutch at the touch point. ### Claim 18 (depends on 16) The vehicle of claim 16, wherein the second threshold is greater than the first threshold. ### Claim 19 (depends on 16) The vehicle of claim 16, wherein the controller is further programmed to, responsive to receiving a disconnect clutch fault while the disconnect clutch is at the touch point, the engine is shut down, and the rotor speed is less than the second threshold, retract and open the disconnect clutch. ### Claim 20 (depends on 16) The vehicle of claim 16, wherein the controller is further programmed to, responsive to the expiration of a timer after advancing the disconnect clutch to the touch point while the rotor speed remains below the second threshold, retract and open the disconnect clutch.