# US 10,308,306 B2 · Vehicle rider detection using strain gauges > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,306 B2 - Document ID: US10308306B2 - Status: Granted - Kind: B2 - Application number: 15/911,906 - Filed: 2018-03-05 - Published: 2018-07-12 - Granted: 2019-06-04 - Earliest claimed: 2016-06-02 - Assignees: Future Motion, Inc. - Applicants: Future Motion, Inc. - Inventors: Kyle Jonathan Doerksen; Daniel Wood - Web page: https://patentgrep.com/patent/US10308306B2 ## CPC - B62K 11/007: {Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider} - A63C 17/014: {Wheel arrangements} - A63C 17/016: {with wheels arranged in one track} - A63C 17/08: single-wheel type {with single axis} - A63C 17/12: with driving mechanisms - A63C 17/26: with special auxiliary arrangements, e.g. illuminating, marking, or push-off devices - B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed - B62J 45/41: characterised by the type of sensor - B62J 45/42: characterised by mounting - A63C 2203/12: Electrically powered or heated - B60L 2200/14: Vehicles with one wheel only - B60L 2200/16: Single-axle vehicles - B60L 2200/24: Personal mobility vehicles - B60L 2220/46: Wheel motors, i.e. motor connected to only one wheel - B60L 2240/42: related to electric machines - B60L 2250/22: by presence detection - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/72: Electric energy management in electromobility - 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) - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An electric vehicle may include a board having two deck portions each configured to receive a foot of a rider, and a wheel assembly disposed between the deck portions. A motor assembly may drive the wheel assembly in response to board orientation and rider presence information. A rider detection mechanism may include one or more strain gauges, and may be configured to detect rider presence and rider weight information. A responsiveness of the motor may be automatically adjusted based on the rider weight information. ## Claims ### Claim 1 An electric vehicle comprising: a board including first and second deck portions each configured to receive a left or right foot of a rider; a wheel assembly including a ground-contacting element; a motor assembly mounted to the board and configured to rotate the ground-contacting element around an axle; at least one orientation sensor configured to measure orientation information of the board; a first strain gauge and a second strain gauge spaced apart across a longitudinal centerline of the board and configured to produce rider presence information and to sense strain along a length dimension of the board and along a width dimension of the board; wherein the first strain gauge and the second strain gauge are configured to determine twisting or bending of the board with respect to the longitudinal centerline of the board and with respect to a fulcral axis of the board; and a motor controller in communication with the motor assembly, the motor controller configured to receive the orientation information and the rider presence information, and to cause the motor assembly to propel the electric vehicle based on the board orientation information and the rider presence information. ### Claim 2 (depends on 1) The electric vehicle of claim 1, wherein an aggressiveness of the motor controller response to the board orientation information is selectable by the user. ### Claim 3 (depends on 2) The electric vehicle of claim 2, wherein the selected aggressiveness of the motor controller is associated with a Proportional-Integral-Derivative (PID) loop. ### Claim 4 (depends on 2) The electric vehicle of claim 2, wherein the selected aggressiveness of the motor controller is associated with a current-resistance (IR) compensation circuit. ### Claim 5 (depends on 1) The electric vehicle of claim 1, wherein the ground contacting element extends laterally across at least a majority of a width of the board. ### Claim 6 (depends on 1) The electric vehicle of claim 1, wherein the first and second deck portions are formed as a single piece. ### Claim 7 (depends on 1) The electric vehicle of claim 1, wherein the first and second strain gauges are each disposed on the second deck portion. ### Claim 8 (depends on 1) The electric vehicle of claim 1, wherein the first and second strain gauges each comprise a respective full-bridge strain gauge circuit. ### Claim 9 A self-balancing electric vehicle comprising: a board having a first deck portion and a second deck portion, collectively defining a plane and having a longitudinal axis, the first deck portion configured to support a first foot of a rider oriented generally perpendicular to the longitudinal axis, the second deck portion configured to support a second foot of the rider oriented generally perpendicular to the longitudinal axis; at least one wheel mounted to the board and configured to rotate about an axle coupled to the board; an orientation sensor coupled to the board and configured to sense orientation information of the board; a first strain gauge load cell and a second strain gauge load cell spaced apart across the longitudinal axis of the board, such that the first and second strain gauge load cells sense a strain applied to the board and are configured to produce rider presence information based on the sensed strain; a motor controller configured to receive the orientation information and the rider presence information, and to generate a motor control signal in response; and a motor configured to receive the motor control signal from the motor controller and to rotate the at least one wheel in response, thereby propelling the electric vehicle; wherein the first strain gauge load cell and the second strain gauge load cell are configured to sense strain along a length dimension of the board and along a width dimension of the board; wherein the first strain gauge load cell and the second strain gauge load cell are configured to determine twisting or bending of the board with respect to the longitudinal axis of the board and with respect to a fulcral axis of the board; wherein the motor controller is configured to analyze the sensed strain at the first strain gauge load cell and the second strain gauge load cell and determine rider foot placement; and wherein the motor controller is configured to respond to a change in foot placement by triggering a predetermined set of events. ### Claim 10 (depends on 9) The electric vehicle of claim 9, wherein the first strain gauge load cell comprises a full-bridge strain gauge circuit. ### Claim 11 (depends on 9) The electric vehicle of claim 9, wherein the first strain gauge load cell and the second strain gauge load cell are disposed on the second deck portion. ### Claim 12 (depends on 9) The electric vehicle of claim 9, wherein the first deck portion is coupled to the second deck portion by a rigid frame. ### Claim 13 (depends on 12) The electric vehicle of claim 12, wherein the rigid frame, the first deck portion, and the second deck portion are formed as a single piece. ### Claim 14 (depends on 9) The electric vehicle of claim 9, wherein the at least one wheel extends laterally across at least a majority of a width of the board. ### Claim 15 (depends on 9) The electric vehicle of claim 9, wherein the vehicle includes exactly one wheel. ### Claim 16 (depends on 9) The electric vehicle of claim 9, wherein the predetermined set of events includes motor shut down. ### Claim 17 An electric vehicle comprising: a foot deck having first and second deck portions each configured to support a rider's foot oriented generally perpendicular to a longitudinal axis of the foot deck; a ground-contacting wheel configured to rotate about an axle to propel the electric skateboard; at least one orientation sensor configured to measure an orientation of the foot deck; a first strain gauge load cell and a second strain gauge load cell spaced apart across the longitudinal axis of the foot deck, such that the first and second strain gauge load cells sense a strain applied to the foot deck and are configured to produce rider presence information based on the sensed strain; and an electric motor configured to cause rotation of the ground contacting wheel based on the orientation of the foot deck and the rider presence information; wherein the first strain gauge load cell and the second strain gauge load cell are configured to sense strain along a length dimension of the foot deck and along a width dimension of the foot deck; and wherein the first strain gauge load cell and the second strain gauge load cell are configured to determine twisting or bending of the foot deck with respect to the longitudinal axis of the foot deck and with respect to a fulcral axis of the foot deck. ### Claim 18 (depends on 17) The electric vehicle of claim 17, wherein the first strain gauge load cell comprises a full-bridge strain gauge circuit. ### Claim 19 (depends on 17) The electric vehicle of claim 17, wherein the first strain gauge load cell and the second strain gauge load cell each consist of exactly one strain gauge, and the strain gauges are spaced apart symmetrically across a width of the foot deck, on either side of the longitudinal axis. ### Claim 20 (depends on 17) The electric skateboard of claim 17, wherein a responsiveness characteristic of the electric motor corresponds to a change in a voltage applied to the electric motor for a given change in the orientation of the foot deck.