# US 8,543,294 B2 · Coaxial two-wheeled vehicle and its control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,294 B2 - Document ID: US8543294B2 - Status: Granted - Kind: B2 - Application number: 13/481,136 - Filed: 2012-05-25 - Published: 2012-09-13 - Granted: 2013-09-24 - Earliest claimed: 2008-07-29 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Susumu Oikawa - Inventors: Susumu Oikawa - Web page: https://patentgrep.com/patent/US8543294B2 ## CPC - G05D 1/0891: {specially adapted for land vehicles} - B60L 15/2036: {Electric differentials, e.g. for supporting steering vehicles} - B62K 11/007: {Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider} - A63C 17/01: Skateboards (A63C17/02 - A63C17/28 take precedence) - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/72: Electric energy management in electromobility - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - B62K: CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDECARS, FORECARS, OR THE LIKE - A63C: SKATES; SKIS; ROLLER SKATES; DESIGN OR LAYOUT OF COURTS, RINKS OR THE LIKE (water skis B63B32/00, B63B34/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract To provide a coaxial two-wheeled vehicle capable of performing a turning movement with stability and its control method. A coaxial two-wheeled vehicle in accordance with the present invention includes drive means to drive two coaxially-arranged wheels, turning reference-input input means to input a turning reference input, and control means to control the drive means according to a turning gain based on a turning reference-input input by the turning reference-input input means to thereby perform a turning movement. The control means preferably brings the turning gain to substantially zero when the coaxial two-wheeled vehicle is in a backward traveling state with a backward speed greater than or equal to a first speed, and sets the turning gain to a value greater than zero when a vehicle speed is substantially zero. ## Claims ### Claim 1 A control method for a coaxial two-wheeled vehicle, comprising: detecting a vehicle velocity; and performing turning control so as to decrease a turning radius as the detected vehicle velocity decreases, wherein the coaxial two-wheeled vehicle moves with a rider riding thereon, and if it is determined that a brake control action is initiated during a turning movement and the vehicle velocity is thereby decreased, a decrease of a turning radius is suppressed so that a spiraling-in movement is suppressed. ### Claim 2 (depends on 1) The control method for a coaxial two-wheeled vehicle according to claim 1, wherein if it is determined that a brake control action is initiated during a turning movement, a turning velocity command value used to determine a wheel velocity difference between two wheels is decreased as time elapses. ### Claim 3 (depends on 1) The control method for a coaxial two-wheeled vehicle according to claim 1, wherein the turning velocity command value is decreased by decreasing a gain value, and setting is performed such that the gain value becomes zero when the vehicle velocity becomes zero. ### Claim 4 (depends on 1) The control method for a coaxial two-wheeled vehicle according to claim 1, wherein if it is determined that a brake control action is initiated during a turning movement, a turning velocity command value used to determine a wheel velocity difference between two wheels is decreased as the detected vehicle velocity lowers. ### Claim 5 (depends on 1) The control method for a coaxial two-wheeled vehicle according to claim 1, wherein if it is determined that a brake control action is initiated during a turning movement, (a) a turning velocity command value used to determine a wheel velocity difference between two wheels is decreased as time elapses when the vehicle velocity is less than a predetermined value, and (b) the turning velocity command value is decreased as the vehicle velocity decreases when the vehicle velocity is greater than or equal to the predetermined value. ### Claim 6 (depends on 1) The control method for a coaxial two-wheeled vehicle according to claim 1, wherein the coaxial two-wheeled vehicle comprises: a step portion on which a rider rides; an operation lever portion that is connected to the step portion and used to operate the coaxial two-wheeled vehicle; and a turning operation unit that is provided in the operation lever portion and used to operate a turning movement of the coaxial two-wheeled vehicle. ### Claim 7 (depends on 6) The control method for a coaxial two-wheeled vehicle according to claim 6, wherein if it is determined that a brake control action is initiated during a turning movement, a decrease of a turning radius is suppressed by lowering an operation sensitivity to an operation signal from the operation lever portion or the turning operation unit. ### Claim 8 (depends on 1) The control method for a coaxial two-wheeled vehicle according to claim 1, wherein the coaxial two-wheeled vehicle comprises: a posture sensor that detects a posture value of the coaxial two-wheeled vehicle; a control unit that calculates a posture velocity command value based on the posture value detected by the posture sensor; and a wheel drive unit that rotationally drives a wheel based on a wheel velocity command value calculated from the posture velocity command value from the control unit and the turning velocity command value from a turning control unit that performs turning control.