# US 8,340,884 B1 · Fuel saving method and device for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,340,884 B1 - Document ID: US8340884B1 - Status: Granted - Kind: B1 - Application number: 12/653,826 - Filed: 2009-12-21 - Granted: 2012-12-25 - Earliest claimed: 2008-12-26 - Inventors: Jing He; Hongping He - Web page: https://patentgrep.com/patent/US8340884B1 ## CPC - B60W 30/1882: {characterised by the working point of the engine, e.g. by using engine output chart} - B60W 30/143: {Speed control (B60W30/16 takes precedence)} - B60W 30/18072: {Coasting} - F02D 41/0002: {Controlling intake air} - B60W 2030/18081: {With torque flow from driveshaft to engine, i.e. engine being driven by vehicle} - B60W 2710/0627: Fuel flow rate - F02D 2200/0625: Fuel consumption, e.g. measured in fuel liters per 100 kms or miles per gallon - F02D 2200/1002: Output torque - Y02T 10/40: Engine management systems - Y02T 10/60: Other road transportation technologies with climate change mitigation effect - Y02T 10/84: Data processing systems or methods, management, administration - 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 - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A system and method for maximizing a vehicle's fuel efficiency preferably without inconveniencing the driver, includes maximizing a ratio of a real-time parameter proportional to engine load or engine power to fuel flow or air flow rate referred to herein as the P/F ratio. This ratio is calculated to evaluate engine fuel efficiency. With the system and method, the throttle is operated incrementally to increase or decrease the throttle in a manner to maximize the P/F ratio, thus maximizing fuel efficiency, in a pulse phase. The system and method implement an on and off pulse width modulation (“PWM”) style of control to modulate engine power and acceleration to achieve the speed that the driver desires, based on the position of the accelerator pedal. When the desired speed is achieved, the throttle is released and when the speed drops a sufficient amount, the throttle is re-engaged to reach the desired speed again. When the throttle is disengaged or when the driver releases the accelerator pedal, the system and method implement a glide phase, where the vehicle coasts without use of fuel or in neutral with very limited use of fuel and minimum engine drag. ## Claims ### Claim 1 A system for controlling a vehicle having a combustible fuel powered engine, the system comprising: i. means for sensing a first parameter proportional to power and for sensing a second parameter proportional to fuel flow; ii. a controller for receiving the first and second parameters and dynamically determining a power to fuel ratio (P/F) by dividing the first parameter by the second parameter, and for comparing the P/F ratio to a previously determined P/F ratio; iii. means for selectively adjusting, by selecting one of maintaining, increasing and decreasing, throttle to maximize the P/F ratio at any given moment up to a predetermined speed, wherein the controller increases throttle in response to the P/F ratio being greater than the previously determined P/F ratio when the previous action was to increase throttle, wherein the controller increases throttle in response to the P/F ratio being less than the previously determined P/F ratio when the previous action was to decrease throttle, wherein the controller decreases throttle in response to the P/F ratio being greater than the previously determined P/F ratio when the previous action was to decrease throttle, and wherein the controller decreases throttle in response to the P/F ratio being less than the previously determined P/F ratio when the previous action was to increase throttle; and iv. means for allowing the vehicle to coast upon reaching the predetermined speed, and when vehicle speed has dropped a predetermined amount, enabling the means for selectively adjusting to increase vehicle speed again. ### Claim 2 (depends on 1) The system of claim 1, wherein the means for selectively adjusting comprises a servo-motor mounted on an accelerator pedal of the vehicle. ### Claim 3 (depends on 1) The system of claim 1, wherein the means for selectively adjusting comprises an existing throttle actuator in the vehicle for cruise control. ### Claim 4 (depends on 1) The system of claim 1, wherein the means for allowing the vehicle to coast comprises means for initiating a shift of the vehicle's transmission from drive to neutral in response to a glide control signal from the controller, the controller initiating the glide control signal upon the vehicle reaching the predetermined speed, and for initiating a shift of the vehicle's transmission from neutral to drive in response to a drive control signal from the controller, the controller initiating the drive control signal upon the vehicle dropping to the predetermined amount below the predetermined speed. ### Claim 5 (depends on 1) The system of claim 1, wherein there is an accelerator sensor for determining accelerator position, and the controller determines the predetermined speed based on a signal from the accelerator sensor. ### Claim 6 (depends on 1) The system of claim 1, wherein the means for sensing comprises accessing the vehicle's existing sensors via OBD II protocol communications. ### Claim 7 (depends on 1) The system of claim 1, wherein the controller is disposed within the vehicle's existing electronic control module. ### Claim 8 (depends on 1) The system of claim 1, wherein there is a means for actuating transmission gear changes, and the controller, in addition to deciding whether to increase or decrease fuel supplied to the engine via the throttle, also makes a decision as to whether there should be a shift of transmission from a lower to a higher gear, or from a higher to a lower gear, for increasing the P/F ratio to a maximum. ### Claim 9 (depends on 1) The system of claim 1, wherein system further comprises: i. means for sensing when a threshold speed is attained by the vehicle; ii. means for accelerating beyond the threshold speed; iii. means for sensing a first duration of time (P) during which accelerating beyond the threshold speed occurs; and iv. wherein the controller further comprises means for initiating coasting of the vehicle upon achieving a predetermined condition, and for determining a second duration of time (G) for coasting as a function of the first duration of time, and for re-initiating accelerating after the second duration of time. ### Claim 10 (depends on 9) The system of claim 9, wherein the second duration of time (G) is equal to the first duration of time (P) divided by a constant (X). ### Claim 11 A method for controlling a vehicle having a combustible fuel powered engine, the method comprising the steps of: i. sensing a first parameter (P) proportional to power; ii. sensing a second parameter (F) proportional to fuel flow; iii. dynamically determining a power to fuel ratio (P/F); comparing the P/F ratio to a previously determined P/F ratio; iv. incrementally increasing or decreasing throttle in response to an increasing or decreasing P/F ratio; and v. allowing the vehicle to coast upon reaching a predetermined speed; and when vehicle speed has dropped by a predetermined amount, repeating the steps (i) to (iv). ### Claim 12 (depends on 11) The method of claim 11, wherein in the step (iv) of increasing or decreasing throttle, the throttle is adjusted automatically. ### Claim 13 (depends on 12) The method of claim 12, wherein the throttle is increased or decreased automatically by using a servo-motor. ### Claim 14 (depends on 12) The method of claim 12, wherein the throttle is increased or decreased automatically by using an existing throttle actuator in the vehicle for cruise control. ### Claim 15 (depends on 11) The method of claim 11, wherein the step of coasting includes automatically shifting the vehicle's transmission from drive to neutral upon reaching the predetermined speed, and a step of automatically shifting from neutral to drive in response to the vehicle's speed dropping by the predetermined amount below the predetermined speed at the end of coasting. ### Claim 16 (depends on 11) The method of claim 11, wherein there is a step of determining a position of an accelerator pedal of the vehicle for determining the predetermined speed. ### Claim 17 (depends on 11) The method of claim 11, wherein there is a step of using existing sensors of the vehicle, accessed through OBD II protocol communications, for performing the steps of (i) and (ii) of sensing. ### Claim 18 (depends on 11) The method of claim 11, wherein there is a step of using an existing electronic control module of the vehicle for performing the steps of (iii) dynamically determining and (iv) incrementally increasing or decreasing throttle. ### Claim 19 (depends on 11) The method of claim 11, wherein the vehicle has a transmission and there is a controller, and there is a step of using the controller determine whether the transmission should shift gear from a lower gear to a higher gear or from a higher gear to a lower gear to increase the P/F ratio. ### Claim 20 (depends on 11) The method of claim 11, further comprising the steps of: i. sensing when a threshold speed is attained by the vehicle; ii. accelerating the vehicle beyond the threshold speed; iii. sensing a first duration of time (P) during which accelerating beyond the threshold speed occurs; and iv. initiating coasting of the vehicle upon achieving a predetermined condition, and determining a second duration of time (G) for coasting as a function of the first duration of time, and for re-initiating accelerating after the second duration of time. ### Claim 21 (depends on 20) The method of claim 20, wherein the second duration of time (G) is equal to the first duration of time (P) divided by a constant (X). ### Claim 22 (depends on 20) The method of claim 20, wherein the second duration of time (G) is equal to the first duration of time (P) divided by a constant (X′), then subtracting the first duration of time (P). ### Claim 23 (depends on 22) The system of claim 22, wherein the operator of the throttle is the throttle actuator and the throttle is increased, decreased, or maintained automatically to operate the engine at optimal efficiency by maximizing the P/F ratio. ### Claim 24 (depends on 23) The system of claim 23, wherein the controller includes means for initiating adjustments to the throttle to maintain the engine working at optimal efficiency with the P/F ratio maximized for a certain period of time, and for initiating a complete release of the throttle to allow the vehicle to coast in between periods of inducing the engine to work at optimal efficiency. ### Claim 25 (depends on 23) The system of claim 23, further comprising means for sensing the accelerator pedal position, and the controller further comprises means for translating the accelerator pedal position into an alteration to a duration of time during which the controller maintains the engine working at optimal efficiency and to a duration of time during which the controller initiates a complete release of the throttle to allow the vehicle to coast in between periods of inducing the engine to work at optimal efficiency. ### Claim 26 A system for controlling a vehicle having a combustible fuel powered engine, the system comprising: i. means for sensing during operation of the vehicle by an operator at predetermined intervals a first real time parameter proportional to power and for sensing during operation of the vehicle by the operator at the predetermined intervals a second real time parameter proportional to fuel flow; ii. a controller for receiving the first and second real time parameters and dynamically determining a real time current power to fuel ratio (P/F) during operation of the vehicle by the operator at the predetermined intervals and comparing the real time current P/F ratio to a previously determined real time current P/F ratio during operation of the vehicle by the operator determined at a previous last one of the predetermined intervals; iii. means for providing an indication to a driver of the vehicle for increasing throttle to maximize the P/F ratio based on the comparison of the real time current P/F ratio and the previously determined real time current P/F ratio at the previous last one of the predetermined intervals, and iv. means for providing another indication to the driver of the vehicle for reducing throttle to maximize the P/F ratio based on the comparison of the real time current P/F ratio and the previously determined real time current P/F ratio at the previous last one of the predetermined intervals. ### Claim 27 A method for controlling a vehicle having a combustible fuel powered engine, the method comprising the steps of: i. sensing during operation of the vehicle by an operator at predetermined intervals a first real time parameter proportional to power; ii. sensing during operation of the vehicle by the operator at the predetermined intervals a second real time parameter (f) proportional to fuel flow; iii. dynamically determining a real time current power to fuel ratio (P/F) during operation of the vehicle by the operator at the predetermined intervals; iv. comparing the real time current P/F ratio to a previously determined real time current P/F ratio during operation of the vehicle by the operator determined at a previous last one of the predetermined intervals; v. providing a first indication to a driver of the vehicle for increasing throttle to maximize the real time current P/F ratio based on the comparison of the real time current P/F ratio and the previously determined real time current P/F ratio at the previous last one of the predetermined intervals; vi. providing a second indication to a driver of the vehicle for maintaining the throttle in the same position to maximize the real time current P/F ratio based on the comparison of the real time current P/F ratio and the previously determined real time current P/F ratio at the previous last one of the predetermined intervals; and vii. providing a third indication to the driver of the vehicle for decreasing throttle to maximize the real time current P/F ratio based on the comparison of the real time current P/F ratio and the previously determined real time current P/F ratio. ### Claim 28 A system for controlling a vehicle having a combustible fuel powered engine, the system comprising: i. means for sensing during operation of the vehicle by an operator at predetermined intervals a first real time parameter proportional to power and for sensing during operation of the vehicle by the operator at the predetermined intervals a second real time parameter proportional to fuel flow; ii. a controller for receiving the first and second real time parameters and dynamically determining a real time current power to fuel ratio (P/F) during operation of the vehicle by the operator at the predetermined intervals, and comparing the real time current P/F ratio to a previously determined real time current P/F ratio during operation of the vehicle by the operator determined at a previous one of the predetermined intervals; iii. the controller further comprising means for generating signals to an operator of the throttle as to whether the throttle should be increased, decreased, or maintained in order to maximize the P/F ratio and thus maintain the engine running at optimal efficiency based on the comparison of the real time current P/F ratio and the previously determined real time current P/F ratio. ### Claim 29 A system for controlling a vehicle having a combustible fuel powered engine, the system comprising: means for sensing a first parameter proportional to power and for sensing a second parameter proportional to fuel flow; a controller for receiving the first and second parameters and dynamically determining a power to fuel ratio (P/F), and comparing the current P/F ratio to a previously determined P/F ratio; the controller further comprising means for generating signals to an operator of the throttle as to whether the throttle should be increased, decreased, or maintained in order to maximize the P/F ratio and thus maintain the engine running at optimal efficiency, wherein the operator of the throttle is a throttle actuator and the throttle is increased, decreased, or maintained automatically to operate the engine at optimal efficiency by maximizing the P/F ratio. ### Claim 30 (depends on 29) The system of claim 29, wherein the controller includes means for initiating adjustments to the throttle to maintain the engine working at optimal efficiency with the P/F ratio maximized for a certain period of time, and for initiating a complete release of the throttle to allow the vehicle to coast in between periods of inducing the engine to work at optimal efficiency. ### Claim 31 (depends on 29) The system of claim 29, further comprising means for sensing the accelerator pedal position, and the controller further comprises means for translating the accelerator pedal position into an alteration to a duration of time during which the controller maintains the engine working at optimal efficiency and to a duration of time during which the controller initiates a complete release of the throttle to allow the vehicle to coast in between periods of inducing the engine to work at optimal efficiency. ### Claim 32 (depends on 29) The system of claim 29, wherein there is a means for sensing the accelerator pedal position and the system maintains the engine working at optimal efficiency up to a predetermined speed, then allows the vehicle to coast until the vehicle speed drops by a predetermined amount below the predetermined speed, upon which the system increases throttle to use the engine in its most efficient state again. ### Claim 33 A system for controlling a vehicle having a combustible fuel powered engine, the system comprising: i. means for detecting engine efficiency; ii. means for increasing and decreasing throttle to induce and maintain the engine at optimal efficiency; iii. a controller for initiating adjustments to the throttle to maintain the engine working at optimal efficiency for a certain period of time, and for initiating a complete release of the throttle to allow the vehicle to coast in between periods of inducing the engine to work at optimal efficiency; iv. a sensor for detecting an accelerator pedal position, and wherein the controller translates the accelerator pedal position into a drivers' desired speed, wherein until the driver's desired speed is reached, the controller maintains the engine working at optimal efficiency and when the driver's desired speed is reached, the controller initiates a complete release of the throttle to allow the vehicle to coast. ### Claim 34 (depends on 33) The system of claim 33, wherein the means for detecting engine efficiency comprises sensing a first parameter proportional to power and a second parameter proportional to fuel flow, and determining a power to fuel (P/F) ratio dynamically, and wherein a most recently determined P/F ratio is compared with a previous value of the P/F ratio. ### Claim 35 (depends on 33) The system of claim 33, wherein the means for detecting comprises existing sensors of the vehicle and the controller accesses these signals via OBD II protocol communications. ### Claim 36 (depends on 33) The system of claim 33, wherein the controller is disposed within the vehicle's existing electronic control module. ### Claim 37 (depends on 33) The system of claim 33, wherein the controller includes means for initiating a shift of a vehicle transmission from drive to neutral in response to a glide control signal from the controller, and means for initiating a shift of the vehicle's transmission from neutral to drive in response to a drive control signal from the controller. ### Claim 38 (depends on 33) The system of claim 33, wherein the accelerator pedal position translates into a predetermined speed, there is a means for sensing vehicle speed, and the controller operates the throttle to induce the engine to accelerate the vehicle up to a predetermined threshold speed at optimal efficiency, then initiates a complete release of the throttle to allow the vehicle to coast upon reaching that threshold speed, then initiates acceleration again when the vehicle speed has dropped to a predetermined amount below the predetermined speed; the controller thus initiates alternating periods of acceleration and coasting, while maintaining the engine at optimal efficiency threshold during acceleration periods. ### Claim 39 (depends on 33) The system of claim 33, wherein the accelerator pedal position translates into a predetermined ratio P/(P+G) where P is the first duration of time during which the controller operates the engine to run fuel efficiently and G is the second duration of time during which the vehicle coasts, and the accelerator pedal position directly controls the ratio P/(P+G). ### Claim 40 A method for controlling a vehicle having a combustible fuel powered engine, the method comprising the steps of: i. sensing the engine's efficiency or state in real time; ii. determining how to induce the engine to run or maintain the engine running at optimal efficiency from the current engine state; iii. selectively increasing and decreasing throttle to induce the engine to run or maintain the engine running at optimal efficiency; iv. repeating steps (i) to (iii) until a predetermined speed or a predetermined duration of time has been reached; v. allowing the vehicle to coast upon reaching a predetermined speed or a predetermined duration of time; vi. when either the vehicle speed has dropped by a predetermined amount, or another predetermined duration of time has passed, repeat steps (i) to (v) above. ### Claim 41 (depends on 40) The method of claim 40, wherein the step of sensing the engine's efficiency in step (i) is accomplished by sensing a first parameter proportional to power and a second parameter proportional to fuel flow, generating a power over fuel ratio (P/F ratio), and wherein the step of determining how to run the engine at optimal efficiency includes comparing the current P/F ratio to a previously determined P/F ratio. ### Claim 42 (depends on 40) The method of claim 40, wherein in the step (iii) of increasing or decreasing the throttle, the throttle is adjusted automatically using a throttle actuator. ### Claim 43 (depends on 42) The method of claim 42, wherein the throttle is increased automatically by using an existing throttle actuator for cruise control in the vehicle. ### Claim 44 (depends on 40) The method of claim 40, wherein the step of coasting (v) includes shifting the vehicle's transmission from drive to neutral during the coasting period and shifting the vehicle's transmission from neutral to drive at the end of the coasting period. ### Claim 45 (depends on 40) The method of claim 40, wherein in step (i) of sensing sensors already existing in the vehicle are used, and accessed through OBD II protocol communications. ### Claim 46 (depends on 40) The method of claim 40, wherein there is a step of using an existing electronic central module for making decisions and initiating actions in steps (ii) to (vi). ### Claim 47 (depends on 40) The method of claim 40, wherein there is an accelerator pedal position sensor and the accelerator pedal position determines the predetermined speed in steps (iv) to (vi). ### Claim 48 (depends on 40) The method of claim 40, wherein there is an accelerator pedal position sensor and the accelerator pedal position determines at least one of the predetermined duration of time (P) in step (iv), the predetermined duration of time (G) in step (v), and the ratio P/(P+G).