# US 12,760,690 B2 · Electronic throttle control of snowmobile with two-stroke internal-combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,760,690 B2 - Document ID: US12760690B2 - Status: Granted - Kind: B2 - Application number: 18/825,014 - Filed: 2024-09-05 - Published: 2025-03-20 - Granted: 2026-10-13 - Earliest claimed: 2023-09-18 - Assignees: Polaris Industries Inc. - Applicants: Polaris Industries Inc. - Inventors: Dallas Blake - Web page: https://patentgrep.com/patent/US12760690B2 ## CPC - F02D 41/0002: {Controlling intake air} - F02B 75/02: Engines characterised by their cycles, e.g. six-stroke - F02D 9/1065: {Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like} - F02D 41/22: Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} - F02D 41/38: of the high pressure type - F02P 5/1502: {using one central computing unit} - F02B 2075/025: {two} - F02D 2200/101: Engine speed - F02D 2200/60: said parameters being related to the driver demands or status - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) ## Abstract An electronic throttle-control system that includes: an electronic control unit (ECU) including a processor and a memory storing a throttle-control translation map; a throttle-input sensor in electrical communication with the ECU and configured to sense an input from an operator-actuated throttle device; and a 2-stroke internal-combustion engine. The 2-stroke internal-combustion engine may include: an electronic throttle-valve actuator in electrical connection with the ECU; a throttle body for controlling airflow to combustion chambers of the engine and defining first and second throttle bores; first and second throttle valves in the bores; and a throttle valve control shaft coupled to the throttle valves and the actuator, such that movement of the actuator causes the throttle valve control shaft to rotate and move the first and second throttle valves; and a throttle-position sensor in electrical communication with the ECU sensing an actual position of the first and second throttle valves. ## Claims ### Claim 1 An electronic throttle-control system for a snowmobile, comprising: an electronic control unit (ECU) including a processor and a memory device storing at least one throttle-control translation map; a throttle-input sensor in electrical communication with the ECU and configured to sense an input from an operator-actuated throttle device; a 2-stroke internal-combustion engine, including: an electronic throttle-valve actuator in electrical connection with the ECU and having an actuator motor and gear train; a throttle body for controlling airflow to one or more combustion chambers of the 2-stroke internal-combustion engine, the throttle body defining a first throttle bore and a second throttle bore; a first throttle valve in the first throttle bore and a second throttle valve in the second throttle bore; and a throttle valve control shaft coupled to the first throttle valve and the second throttle valve, and to the gear train, such that movement of the actuator motor and gear train causes the throttle valve control shaft to rotate and move the first and second throttle valves; a throttle-position sensor in electrical communication with the ECU and configured to sense an actual position of the first and second throttle valves; wherein the ECU is configured to receive a signal representing a throttle-position input from the throttle-input sensor and to determine a throttle-demand position corresponding to a position of the first throttle valve in the first throttle bore and a position of the second throttle valve in the second throttle bore, based on the throttle-position input and throttle-control translation map, and wherein the ECU is configured to: limit a throttle-demand position based on at least one of ground speed, user-selected limit parameters, or fault-state limit positions; and transition from the idle control mode to a translation-map control mode when: the throttle-demand position exceeds a predetermined idle throttle threshold, and the engine speed exceeds a predetermined idle engine-speed threshold. ### Claim 2 (depends on 1) The electronic throttle control system of claim 1, further comprising an engine-speed sensor in electrical communication with the ECU and configured to sense a speed of the 2-stroke internal-combustion engine. ### Claim 3 (depends on 2) The electronic throttle control system of claim 2, wherein the ECU is configured to control the actuator during a start mode to decrease the throttle output when a sensed speed of the 2-stroke internal-combustion engine is less than an engine-speed threshold. ### Claim 4 (depends on 1) The electronic throttle control system of claim 1, wherein the ECU is further configured to: limit a throttle-demand position based on engine speed. ### Claim 5 (depends on 1) The electronic throttle control system of claim 1, wherein a bore diameter of the first throttle bore is substantially the same as a bore diameter of the second throttle bore and a throttle-bore pitch of the first throttle bore to the second throttle bore is greater than twice the bore diameter. ### Claim 6 (depends on 5) The electronic throttle control system of claim 5, wherein the bore pitch is in a range of 100 mm to 200 mm. ### Claim 7 (depends on 1) The electronic throttle control system of claim 1, wherein the bore diameter is in a range of 40 mm to 60 mm. ### Claim 8 (depends on 1) A snowmobile, comprising the electronic throttle control system of claim 1. ### Claim 9 (depends on 1) The electronic throttle control system of claim 1, wherein the memory stores a plurality of throttle-control translation maps defining different relationships between throttle-position input and throttle-demand position, and wherein the ECU is configured to selectively implement one of the plurality of throttle-control translation maps based on a user-selected operating mode. ### Claim 10 (depends on 9) The electronic throttle control system of claim 9, wherein at least one of the plurality of throttle-control translation maps is configured such that, for at least a portion of a throttle-position input range, the throttle-demand position exceeds the throttle-position input. ### Claim 11 (depends on 9) The electronic throttle control system of claim 9, wherein at least one of the plurality of throttle-control translation maps is configured such that, for at least a portion of a throttle-position input range, the throttle-demand position is less than the throttle-position input. ### Claim 12 (depends on 1) The electronic throttle control system of claim 1, wherein the ECU is configured to: compare the throttle-demand position to a predetermined idle throttle position stored in the memory; and when the throttle-demand position is less than the predetermined idle throttle position and a detected engine speed is less than a predetermined idle engine-speed threshold, control the actuator according to an idle control mode to maintain the engine speed at a target idle speed. ### Claim 13 (depends on 1) The electronic throttle control system of claim 1, wherein the ECU is configured to: compare an actual throttle position detected by the throttle-position sensor to the throttle-demand position; and discontinue fuel injection and/or ignition of the 2-stroke internal-combustion engine when the actual throttle position exceeds the throttle-demand position for greater than a predetermined time interval. ### Claim 14 (depends on 1) The electronic throttle control system of claim 1, further comprising a vehicle-speed sensor configured to detect a ground speed of the snowmobile, wherein the ECU is configured to override the throttle-control translation map and command a reduced throttle-demand position when the detected ground speed exceeds a predetermined maximum ground-speed limit. ### Claim 15 An electronic throttle-control system for a snowmobile having a 2-stroke internal-combustion engine, comprising: an electronic control unit (ECU) including a processor and a memory storing: a plurality of throttle-control translation maps defining different non-identical relationships between a throttle-position input and a throttle-demand position, and an idle-speed control routine configured to maintain engine speed at a target idle speed; a throttle-input sensor configured to detect a position of an operator-actuated throttle device and generate a throttle-position input signal; a vehicle-speed sensor configured to detect a ground speed of the snowmobile; an engine-speed sensor configured to detect a speed of the 2-stroke internal-combustion engine; a throttle body defining a first throttle bore and a second throttle bore; a first throttle valve disposed in the first throttle bore and a second throttle valve disposed in the second throttle bore; a common throttle shaft coupling the first throttle valve and the second throttle valve; an electronic throttle-valve actuator coupled to the common throttle shaft and in electrical communication with the ECU; and a throttle-position sensor configured to detect an actual position of the first and second throttle valves; wherein the ECU is configured to: select one of the plurality of throttle-control translation maps based on a user-selected operating mode; determine the throttle-demand position based on the selected throttle-control translation map and the throttle-position input signal; operate in an idle control mode when the throttle-demand position is below a predetermined idle threshold and the engine speed is below a predetermined idle engine-speed threshold; and transition from the idle control mode to a translation-map control mode when: the throttle-demand position exceeds a predetermined idle throttle threshold, and the engine speed exceeds a predetermined idle engine-speed threshold. ### Claim 16 (depends on 15) The electronic throttle-control system of claim 15, wherein at least one of the plurality of throttle-control translation maps defines, over at least a portion of a throttle-position input range, a throttle-demand position that is greater than the throttle-position input. ### Claim 17 (depends on 15) The electronic throttle-control system of claim 15, wherein the ECU is configured to override the selected throttle-control translation map when the engine speed exceeds a predetermined maximum engine-speed threshold and to command a reduced throttle-demand position to maintain engine speed below the predetermined maximum engine-speed threshold.