# US 11,440,618 B2 · Electric assist system and electric assist vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,618 B2 - Document ID: US11440618B2 - Status: Granted - Kind: B2 - Application number: 16/449,511 - Filed: 2019-06-24 - Published: 2019-10-10 - Granted: 2022-09-13 - Earliest claimed: 2016-12-28 - Assignees: Yamaha Hatsudoki Kabushiki Kaisha - Applicants: Yamaha Hatsudoki Kabushiki Kaisha - Inventors: Mitsuharu Hasumi - Web page: https://patentgrep.com/patent/US11440618B2 ## CPC - B62M 6/50: characterised by detectors or sensors, or arrangement thereof - B60L 9/18: fed from DC supply lines - B60L 50/20: using propulsion power generated by humans or animals - B62M 6/45: Control or actuating devices therefor - B62M 6/55: power-driven at crank shafts parts - B62M 6/90: Batteries - B60L 2200/12: Bikes - B62J 43/13: on rider-propelled cycles with additional electric propulsion - B62J 43/20: characterised by the mounting - B62M: RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR {SINGLE-TRACK} CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES (arrangements or mounting of transmissions in vehicles in general B60K; transmission elements per se F16) - 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 - B62J: CYCLE SADDLES OR SEATS; AUXILIARY DEVICES OR ACCESSORIES SPECIALLY ADAPTED TO CYCLES AND NOT OTHERWISE PROVIDED FOR, e.g. ARTICLE CARRIERS OR CYCLE PROTECTORS ## Abstract An electric assist system for an electric assist vehicle includes a crankshaft rotatable by human power of a rider applied to a pedal, an electric motor that generates an assist power that assists the human power of the rider, a controller that controls a magnitude of the assist power to be generated by the electric motor, and an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle. The controller changes the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal. ## Claims ### Claim 1 An electric assist system for an electric assist vehicle including a pedal, the electric assist system comprising: a crankshaft that is rotatable by human power of a rider applied to the pedal; an electric motor that generates an assist power to assist the human power of the rider; a controller configured or programmed to control a magnitude of the assist power to be generated by the electric motor; an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle; and a torque sensor that outputs a signal in accordance with a torque generated at the crankshaft; wherein the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal; the torque generated at the crankshaft by the human power of the rider applied to the pedal changes in accordance with a rotation of the crankshaft; the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with a change in the torque; a magnitude of the torque generated at the crankshaft by the human power of the rider applied to the pedal increases and decreases in accordance with the rotation of the crankshaft; and the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration between an adjacent ridge and trough of the torque that increases and decreases. ### Claim 2 An electric assist system for an electric assist vehicle including a pedal, the electric assist system comprising: a crankshaft that is rotatable by human power of a rider applied to the pedal; an electric motor that generates an assist power to assist the human power of the rider; a controller configured or programmed to control a magnitude of the assist power to be generated by the electric motor; an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle; and a torque sensor that outputs a signal in accordance with a torque generated at the crankshaft; wherein the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal; the torque generated at the crankshaft by the human power of the rider applied to the pedal changes in accordance with a rotation of the crankshaft; the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with a change in the torque; a magnitude of the torque generated at the crankshaft by the human power of the rider applied to the pedal increases and decreases in accordance with the rotation of the crankshaft; the controller is configured or programmed to determine a difference between a maximum value and a minimum value of the acceleration between an adjacent ridge and trough of the torque that increases and decreases; and the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with the difference between the maximum value and the minimum value of the acceleration. ### Claim 3 (depends on 1) The electric assist system of claim 1, wherein the controller is configured or programmed to increase the assist power to be generated by the electric motor as the change in the acceleration between the adjacent ridge and trough of the torque that increases and decreases becomes larger. ### Claim 4 An electric assist system for an electric assist vehicle including a pedal, the electric assist system comprising: a crankshaft that is rotatable by human power of a rider applied to the pedal; an electric motor that generates an assist power to assist the human power of the rider; a controller configured or programmed to control a magnitude of the assist power to be generated by the electric motor; an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle; and a sensor that detects a rotation of the crankshaft; wherein the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal; and the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration during a half rotation of the crankshaft. ### Claim 5 (depends on 4) The electric assist system of claim 4, wherein the controller is configured or programmed to determine a difference between a maximum value and a minimum value of the acceleration during the half rotation of the crankshaft; and the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with the difference between the maximum value and the minimum value of the acceleration. ### Claim 6 (depends on 4) The electric assist system of claim 4, wherein the sensor that detects the rotation of the crankshaft is a torque sensor that detects a torque generated at the crankshaft; and the controller is configured or programmed to determine the rotation of the crankshaft based on a change in the torque. ### Claim 7 (depends on 4) The electric assist system of claim 4, wherein the sensor that detects the rotation of the crankshaft is a rotation sensor. ### Claim 8 (depends on 2) The electric assist system of claim 2, wherein the controller is configured or programmed to increase the assist power to be generated by the electric motor in a case in which the difference between the maximum value and the minimum value of the acceleration is a first predetermined value or larger. ### Claim 9 (depends on 2) The electric assist system of claim 2, wherein the controller is configured or programmed to decrease the assist power to be generated by the electric motor in a case in which the difference between the maximum value and the minimum value of the acceleration is smaller than a second predetermined value. ### Claim 10 (depends on 2) The electric assist system of claim 2, wherein the controller is configured or programmed to store, in advance, a table in which values of the difference between the maximum value and the minimum value of the acceleration are divided into a plurality of ranges; and the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a range, among the plurality of ranges, to which the difference between the maximum value and the minimum value of the acceleration determined by the acceleration sensor belongs. ### Claim 11 (depends on 10) The electric assist system of claim 10, wherein the plurality of ranges include a first range and a second range, the second range including values of the difference larger than the values of the difference in the first range; and in a case in which the difference is a value belonging to the second range, the controller is configured or programmed to increase the assist power to be generated by the electric motor as compared with the assist power in a case in which the difference is a value belonging to the first range. ### Claim 12 (depends on 2) The electric assist system of claim 2, wherein the controller is configured or programmed to store in advance: a plurality of assist modes different from each other in a relationship between the human power of the rider and the assist power; and a table in which values of the difference between the maximum value and the minimum value of the acceleration are divided into a plurality of ranges; and the controller is configured or programmed to change the assist mode in accordance with a range, among the plurality of ranges, to which the difference between the maximum value and the minimum value of the acceleration determined by the acceleration sensor belongs. ### Claim 13 (depends on 12) The electric assist system of claim 12, wherein the plurality of ranges include a first range and a second range, the second range including values of the difference larger than the values of the difference in the first range; the plurality of assist modes include a first assist mode and a second assist mode, the second assist mode including an assist power larger than an assist power in the first assist mode; in a case in which the difference between the maximum value and the minimum value of the acceleration determined by the acceleration sensor belongs to the first range, the controller is configured or programmed to cause the electric motor to generate an assist power in accordance with the first assist mode; and in a case in which the difference between the maximum value and the minimum value of the acceleration determined by the acceleration sensor belongs to the second range, the controller is configured or programmed to cause the electric motor to generate an assist power in accordance with the second assist mode. ### Claim 14 (depends on 2) The electric assist system of claim 2, further comprising: a sensor that detects the rotation of the crankshaft; and a sensor that detects a running speed of the electric assist vehicle; wherein the controller is configured or programmed to determine whether or not conditions are fulfilled that: a number of rotations of the crankshaft is a predetermined number or larger; the running speed of the electric assist vehicle is a predetermined speed or higher; and the difference between the maximum value and the minimum value of the acceleration is smaller than a predetermined value; and when it is determined that the conditions are fulfilled, the controller is configured or programmed to decrease the assist power to be generated by the electric motor. ### Claim 15 An electric assist system for an electric assist vehicle including a pedal, the electric assist system comprising: a crankshaft that is rotatable by human power of a rider applied to the pedal; an electric motor that generates an assist power to assist the human power of the rider; a controller configured or programmed to control a magnitude of the assist power to be generated by the electric motor; an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle; a sensor that detects a rotation of the crankshaft; and a sensor that detects a running speed of the electric assist vehicle; wherein the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal; the controller is configured or programmed to determine whether or not conditions are fulfilled that: a number of rotations of the crankshaft is a predetermined number or larger; the running speed of the electric assist vehicle is a predetermined speed or higher; and the acceleration is of a predetermined value or larger; and when it is determined that the conditions are fulfilled, the controller is configured or programmed to decrease the assist power to be generated by the electric motor. ### Claim 16 An electric assist system for an electric assist vehicle including a pedal, the electric assist system comprising: a crankshaft that is rotatable by human power of a rider applied to the pedal; an electric motor that generates an assist power to assist the human power of the rider; a controller configured or programmed to control a magnitude of the assist power to be generated by the electric motor; an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle; a sensor that detects a rotation of the crankshaft; and a sensor that detects a running speed of the electric assist vehicle; wherein the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal; the controller is configured or programmed to determine whether or not conditions are fulfilled that: a number of rotations of the crankshaft is a predetermined number or larger; the running speed of the electric assist vehicle is a predetermined speed or higher; and the acceleration is a first predetermined value or larger, and then becomes a value smaller than a second predetermined value which is smaller than the first predetermined value; and when it is determined that the conditions are fulfilled, the controller is configured or programmed to decrease the assist power to be generated by the electric motor. ### Claim 17 An electric assist system for an electric assist vehicle including a pedal, the electric assist system comprising: a crankshaft that is rotatable by human power of a rider applied to the pedal; an electric motor that generates an assist power to assist the human power of the rider; a controller configured or programmed to control a magnitude of the assist power to be generated by the electric motor; an acceleration sensor that outputs a signal in accordance with an acceleration in a traveling direction of the electric assist vehicle; a sensor that detects a rotation of the crankshaft; and a sensor that detects a running speed of the electric assist vehicle; wherein the controller is configured or programmed to change the magnitude of the assist power to be generated by the electric motor in accordance with a change in the acceleration that is associated with an operation of the rider rotating the pedal; the controller is configured or programmed to determine whether or not a condition is fulfilled that: a predetermined time period has elapsed in a state in which a number of rotations of the crankshaft is a predetermined number or larger; the running speed of the electric assist vehicle is a predetermined speed or higher; or the acceleration is a predetermined value or larger; and when it is determined that the condition is fulfilled, the controller is configured or programmed to decrease the assist power to be generated by the electric motor. ### Claim 18 (depends on 14) The electric assist system of claim 14, wherein the controller is configured or programmed to include a plurality of assist modes different from each other in a relationship between the human power of the rider and the assist power; and when it is determined that one or more of the conditions is fulfilled, the controller is configured or programmed to control the electric motor to generate an assist power that is smaller than the assist power calculated based on a present one of the plurality of assist modes. ### Claim 19 (depends on 1) An electric assist vehicle, comprising the electric assist system of claim 1.