# US 11,027,721 B2 · Drive force control system for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,721 B2 - Document ID: US11027721B2 - Status: Granted - Kind: B2 - Application number: 16/185,883 - Filed: 2018-11-09 - Published: 2019-05-16 - Granted: 2021-06-08 - Earliest claimed: 2017-11-13 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Tatsuya Imamura; Hideaki Komada; Akiko Nishimine; Yosuke Suzuki; Hidekazu Nagai; Takahito Endo; Hirotsugu Yoshino; Kensei Hata; Hiroki Yasui - Web page: https://patentgrep.com/patent/US11027721B2 ## CPC - B60W 20/50: Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode - B60K 6/365: with the gears having orbital motion - B60K 6/387: Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means - B60K 6/40: characterised by the assembly or relative disposition of components - B60K 6/445: Differential gearing distribution type - B60K 6/543: the transmission being a continuously variable transmission - B60W 20/30: Control strategies involving selection of transmission gear ratio {(control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H)} - F16D 48/06: Control by electric or electronic means, e.g. of fluid pressure - F16H 3/725: {with means to change ratio in the mechanical gearing} - F16H 3/728: {with means to change ratio in the mechanical gearing} - F16H 61/12: Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures} - B60K 2006/381: {characterized by driveline brakes} - B60Y 2200/92: Hybrid vehicles - B60Y 2400/421: Dog type clutches or brakes - F16D 2500/10412: Transmission line of a vehicle - F16D 2500/304: from the clutch - F16H 2037/0873: {with switching means, e.g. to change ranges} - F16H 2061/1244: {Keeping the current state} - F16H 2200/2094: using positive clutches, e.g. dog clutches - Y02T 10/62: Hybrid 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 - 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 - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F16H: GEARING - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A control system for a vehicle that prevents an unintentional mode change when a command signal cannot be transmitted to an engagement device. In the vehicle, HV-Lo mode is established by connecting a carrier to a carrier by a first clutch while disconnecting the carrier from a ring gear by a second clutch, and HV-Lo mode is established by disconnecting the carrier from the carrier by the first clutch while connecting the carrier to the ring gear by the second clutch. A normally stay clutch is used as at least one of the first clutch and the second clutch. ## Claims ### Claim 1 A drive force control system for a vehicle, comprising: an engine; a rotary machine; and a differential mechanism that is configured to perform a differential rotation among a first rotary member connected to the engine, a second rotary member connected the rotary machine, and a third rotary member connected to an output member, the differential mechanism comprises a plurality of rotary elements; a first engagement device that connects a first rotary element and a second rotary element; a second engagement device that connects a third rotary element and a fourth rotary element; and a controller that controls the first engagement device and the second engagement device, wherein at least one of the first engagement device and the second engagement device is a normally stay clutch, and the normally stay clutch is configured to be engaged upon reception of an engagement command signal and disengaged upon reception of a disengagement command signal, and to maintain a current engagement state when a signal transmission to the normally stay clutch is stopped, wherein the differential mechanism is configured to operate in: a first operating mode in which a torque of the engine is delivered to the output member with a first predetermined ratio by engaging any one of the first engagement device and the second engagement device; and a second operating mode in which the torque of the engine is delivered to the output member with a second predetermined ratio that is smaller than the first predetermined ratio by engaging other one of the first engagement device and the second engagement device, wherein the engine is on during the first operating mode and the second operating mode, and wherein the controller is configured to: determine an engagement device in which a failure occurs out of the first engagement device and the second engagement device; determine the engagement device in which the failure occurs is engaged or disengaged; disengage an engagement device working properly if the engagement device in which the failure occurs is engaged; and engage the engagement device working properly if the engagement device in which the failure occurs is disengaged. ### Claim 2 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein the differential mechanism is further configured to operate in: a fixed mode in which a speed ratio between the engine and the output member is constant by engaging the first engagement device and the second engagement device; and a continuously variable mode in which the speed ratio between the engine and the output member is varied continuously by engaging any one of first engagement device and the second engagement device. ### Claim 3 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein the third rotary element includes any one of the first rotary element and the second rotary element. ### Claim 4 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein the fourth rotary element includes a rotary element other than the first rotary element, the second rotary element, and the third rotary element. ### Claim 5 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein both of the first engagement device and the second engagement device are the normally stay clutch. ### Claim 6 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein one of the first engagement device and the second engagement device is a normally open clutch, and wherein the normally open clutch is configured to be engaged upon reception of the engagement command signal, and disengaged when the signal transmission to the normally open clutch is stopped. ### Claim 7 (depends on 5) The drive force control system for the vehicle as claimed in claim 5, further comprising: a prime mover configured to deliver an output torque to the output member without passing through the differential mechanism. ### Claim 8 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein one of the first engagement device and the second engagement device is a normally close clutch, and wherein the normally close clutch is configured to be disengaged upon reception of the disengagement command signal, and engaged when the signal transmission to the normally close clutch is stopped. ### Claim 9 (depends on 1) The drive force control system for the vehicle as claimed in claim 1, wherein the normally stay clutch includes a dog clutch, comprising: a pair of rotary member being opposed to each other while being configured to rotate relatively to each other; a rod that pushes and withdraws one of the rotary members toward/away from the other rotary member upon reception of the engagement command signal or the disengagement command signal; and a compression spring that transmits a load of the rod to said one of the rotary members.