NL2003198C2

NL2003198C2 - Tactile feedback on fuel economy to car driver.

Info

Publication number: NL2003198C2
Application number: NL2003198A
Authority: NL
Inventors: Herman Verhey Wijk
Original assignee: Verhey Van Wijk Beheer B V
Priority date: 2009-07-14
Filing date: 2009-07-14
Publication date: 2011-01-17

Description

TACTILE FEEDBACK ON FUEL ECONOMY TO CAR DRIVER FIELD OF THE INVENTION

The invention relates to a motor vehicle an indicator for indicating to a user of the 5 motor vehicle a level of the fuel economy. The invention also relates to a signal processing system for use in such vehicle, the signal processing system being configured for generating a control signal in dependence on the level of the fuel economy.

BACKGROUND ART

10 Increasing fuel prices, dependence on the import of fuel, and especially environmental pollution, have caused governments and the public to consider fuel economy of a car as a serious issue. Fuel economy is increasingly more becoming the major criterion for a private person or a fleet owner to decide what type of car or truck to purchase. A fuel economy indicator on the dashboard helps the driver to better control fuel consumption and, therefore, 15 costs of operating a car or a truck, by means of adjusting his/her driving style in response to the fuel economy indicated. Also, the indicated fuel economy may indicate to the driver other factors that affect fuel economy. For example, running the onboard air-conditioning unit leads to higher fuel consumption. As another example, running the car with tires that are not properly inflated, leads to higher fuel consumption. As yet another example, driving in a city 20 consumes more fuel than driving the same distance in a rural area because of the city’s infamous start-stop traffic flow. A fuel economy indicator thus can facilitate to minimize fuel consumption and maintain driver-awareness and, as a consequence, save costs and reduce environmental pollution.

Fuel economy indicators are generally known. A fuel economy indicator displays the 25 instantaneous value of miles-per-gallon to the vehicle operator by means of an analog or digital display on the dashboard. The miles-per-gallon value is computed using sensors which provide the instantaneous rates of fuel usage and vehicle speed.

Various methods are known for determining fuel economy. One example is based on the fact that manifold depression in the intake manifold of an internal combustion engine is an 30 indicator of the amount of fuel being consumed by the engine. A weaker sub-atmospheric pressure or depression indicates higher fuel consumption, whereas a stronger sub-atmospheric 2 pressure or depression indicates lower fuel consumption. Accordingly, a fuel economy indication can be obtained by processing the signals from one or more sensors at the intake manifold that are configured for sensing the manifold depression. Another example of determining fuel economy is based on computing the miles-per-gallon value using sensors 5 which provide the instantaneous rates of fuel usage and vehicle speed. Fuel usage is then determined by sensors that measure the flow of fuel from the tank to the engine or the return flow. Yet another example is based on measuring the fuel flow from the tank to the engine and determining the current position of the fuel injector. In still another example, the fuel economy is calculated based on fuel injector pulse width, vehicle road speed and on the engine speed.

10 Accordingly, it is well known to determine fuel economy of an internal combustion engine in operational use. It is also well known how to generate a signal indicative of an absolute or relative fuel economy and to display to the driver an indication of the fuel economy, e.g., via a gauge, colored lamps, or a display with digital representation, etc., on the dashboard.

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SUMMARY OF THE INVENTION

The inventor has realized that a visual indication for alerting the driver of the motor vehicle to the current fuel economy is less then optimal, when the driver’s visual senses are already fully occupied, if not overloaded, with operating the vehicle and navigating the traffic.

20 The visual signal has to compete with other visual information that the driver has to process, e.g., the constantly changing traffic situations, visual directions of the onboard navigation system, the dashboard lights of the turn indicators or of low fuel level, etc. Accordingly, a visual fuel economy indication may be distracting, confusing or may even not be noticed at all by the driver.

25 The inventor therefore proposes to use a fuel economy indication of another modality and, moreover, to have it synergistically combined with the conventional user controls of the motor vehicle.

More specifically, the inventor proposes a motor vehicle comprising an internal combustion engine for propelling the motor vehicle. The motor vehicle also has an accelerator 30 device for controlling a change in fuel supply to the internal combustion engine in response to a change in a position of the accelerator device. The position is controllable by a user of the 3 motor vehicle. Examples of such accelerator device are the gas pedal (“accelerator”) of a car or truck, or the twist grip throttle on the handlebars of a motorcycle or another single-track motor vehicle. Such an accelerator device is part of the conventional user interface of a motor vehicle for user control of the actual road speed of the vehicle. The motor vehicle also 5 comprises a first signal processing system for determining a level of fuel economy of the internal combustion engine during operational use of the motor vehicle; and a second signal processing system for generating a control signal in dependence on the level determined. The motor vehicle further comprises an indicator for indicating the determined level to the user of the motor vehicle. In the invention, the indicator comprises an actuator functionally coupled 10 between the second signal processing system and the accelerator device for introducing a tactile signal into the accelerator device under control of the control signal.

The coupling between the first signal processing system and the actuator sees to it, that the actuator receives the control signal. This coupling can be implemented in a wired manner or in a wireless manner, both being well within the capabilities of the person of ordinary skill 15 in the art.

The tactile feedback to the driver via the accelerator device according to the invention uses a sensory channel of the driver different from the visual channel, thus avoiding a sensory overload of the latter. Also, the tactile signal is not going to be obscured or drowned by other tactile perceptions relevant for operating the vehicle, if any. In addition, the functional 20 integration of the actuator with the accelerator device stimulates the driver exactly at that part of the body that actively controls the vehicle’s road speed. That is, the fuel economy indicator in the invention is synergistically integrated with the very control component through which the driver can determine the level of fuel economy. .

In an embodiment, of the invention, the second signal processing system is configured 25 for programming or reprogramming the dependence with respect to an attribute of the tactile signal. The programming or re-programming can be carried out by the user or by a mechanic. Thus, the tactile signal can be customized, e.g., according to the preferences of the driver. The feature “attribute of the tactile signal” refers to a characteristic of the tactile signal as perceived by the driver. Such an attribute includes, for example, one or more of: an intensity 30 of the tactile signal, a frequency of a vibratory tactile signal, a change in resistance against moving the accelerator device, a temporal aspect of the tactile signal such as duration, a 4 profile of the frequency and/or intensity in dependence of a magnitude of the fuel economy currently determined, etc. For example, the intensity of the tactile signal increases with decreasing fuel economy according to a certain profile.

In a further embodiment, the second signal processing system is configured for 5 preventing the introducing of the tactile signal into the accelerator device if the rate of change of the user-controllable position of the accelerator device has a magnitude larger than a predetermined threshold. That is, if the driver pushes the accelerator or turns the grip throttle quicker than at a predetermined threshold rate, it is assumed that the driver does do this intentionally, e.g., to accelerate or to maintain road speed on an incline. It is then preferred to 10 cancel the tactile signal. Optionally, the pre-determined threshold is programmable or re programmable. Optionally, the actuator is configured for being activated or inactivated by the driver, e.g., via a switch on the dashboard. Optionally, the actuator is physically integrated with the accelerator device.

Note that increasingly more road vehicles are designed with a drive-by-wire 15 configuration, wherein the coupling between the accelerator pedal, on the one hand, and the engine on the other hand, is implemented electronically instead of purely mechanical using cables and/or rod linkages. This implies that the electronic infrastructure is already available in the vehicle, to which the functionality of the invention can be added relatively simply, e.g., by means of loading proper software and adding an actuator to the accelerator device.

20 The invention also relates to a second signal processing system for use in a vehicle as specified above. That is, the second signal processing system can be exploited as an after-market add-on to a vehicle already in operational use. Note that such a vehicle has an onboard first signal processing system for determining the level of fuel economy that is usually indicated to the driver via a display monitor or gauge on the dashboard. Now, by inserting the 25 second signal processing system between the first signal processing system, on the one hand, and an actuator coupled with the accelerator device on the other hand, the new functionality of a tactile feedback can be implemented with regard to fuel economy level indication.

The invention also relates to a method of indicating, to a user of a motor vehicle and during operational use of the motor vehicle, a level of fuel economy of an internal combustion 30 engine of the motor vehicle. The motor vehicle comprises an accelerator device for controlling a change in fuel supply to the internal combustion engine in response to a change in a position 5 of the accelerator device. The position is controllable by the user of the motor vehicle. The method comprises: determining the level of fuel economy during the operational use of the motor vehicle; generating a control signal in dependence on the level determined; and introducing a tactile signal into the accelerator device under control of the control signal.

5 An embodiment of the method comprises preventing the introducing of the tactile signal into the accelerator device if a rate of the change of the position has a magnitude larger than a pre-determined threshold.

For completeness, the following documents are mentioned.

US 20040254048 discloses an apparatus for generating tactile force for a vehicle 10 including a motor for generating the tactile force, a spring for generating the tactile force, an electromagnetic brake for cooperatively generating the tactile force with at least one of the motor and the spring, an accelerator pedal and a shift lever. The apparatus generates the tactile force for at least one of the accelerator pedal and the shift lever with a drive-by-wire method. The apparatus comprises a detector for detecting an amount of depression of the accelerator 15 pedal; a throttle control unit for controlling a throttle angle according to a signal indicative of the amount of depression detected by the detector; and a pedal tactile force generator for providing the accelerator pedal with the tactile force according to the signal.

US 20070106475 discloses a vehicle driving assist system that is configured to convey a risk potential relating to a preceding obstacle to a driver using both visual information and 20 haptic information. For example, the vehicle driving assist system executes accelerator pedal actuation reaction force control such that an actuation reaction force is generated in accordance with a risk potential that expresses a degree of convergence between the host vehicle and a preceding obstacle. In order to convey to the driver in a clear manner which preceding obstacle(s) is an obstacle targeted by the risk potential calculation and the reaction 25 force control, the system displays a reference frame or marker at a position corresponding to the targeted obstacle (preceding vehicle).

US 20030130091 discloses a method and device for issuing a feedback signal to the driver of a motor vehicle as soon as an admissible constant load limit of a shifting element in a motor vehicle transmission, especially a starting clutch in an automatic transmission, is 30 exceeded. The feedback signal to the driver takes the form of a haptic signal via an accelerator pedal of the motor vehicle as pulsated motion of the throttle pedal.

6

Above publications demonstrate that actuators, for providing a tactile feedback to an operator of a vehicle, are known and that providing tactile feedback to the driver of a motor vehicle via the accelerator is known to the skilled person as well. Such actuators are also known from, e.g., mobile telephones that provide vibro-tactile sensations such as the E770 5 handset from Samsung upon receiving a call or an SMS message. The force-feedback technology used has been developed by Immersion Corporation. Accordingly, the basic implementing technologies used in the invention are known to the person skilled in the art. However, none of above publications either teaches or suggests the specific functionality as proposed by the inventor.

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BRIEF DESCRIPTION OF THE DRAWING

The invention is explained in further detail, by way of example and with reference to the accompanying drawing, wherein:

Fig. 1 is a block diagram of a vehicle in the invention, and 15 Fig. 2 is a diagram illustrating an attribute of the tactile signal introduced

Throughout the Figures, similar or corresponding features are indicated by same reference numerals.

DETAILED EMBODIMENTS

20 Fig. 1 is a block diagram of a motor vehicle 100 in the invention. Vehicle 100 is designed for use on the public road, e.g., a passenger car, a truck, a motorcycle, etc. Vehicle 100 comprises an internal combustion engine 102 for propelling the motor vehicle. As known, a typical internal combustion engine operates on the basis of introducing a fuel/air mixture into a combustion chamber (cylinder), and igniting this mixture to drive a piston exposed to 25 the combustion and coupled to a crankshaft. A typical example of an internal combustion engine is the petrol (UK) (or: gasoline (US)) engine that uses a separate ignition system for igniting the fuel/air mixture by a spark plug. Another typical example of an internal combustion engine is the diesel engine that uses the heat generated during the piston’s compression stroke to ignite the fuel/air mixture.

30 Vehicle 100 comprises an accelerator device 104 for controlling a change in fuel supply to engine 102 in response to a change in a user-controllable position of accelerator device 104 7 that controls a throttle valve to determine the air intake. If vehicle 100 is a car or truck, accelerator device 104 typically comprises a pedal. If the driver wants to have engine 102 develop more power, e.g., for accelerating or driving up an incline, the driver pushes the pedal with his/her foot into another position closer to the floor of the driver’s compartment. The 5 farther the pedal is pushed the more air is flowing introduced and, as a result, the more fuel is delivered to the combustion chambers of the engine. This applies in general to both engines with carburetors and engines having a mechanical or electronic fuel-injection system. If vehicle 100 is a motorcycle, accelerator device 104 typically comprises a twist grip on the handlebars. If the rider wants to have engine 102 develop more power, e.g., for accelerating, 10 the rider turns the twist grip with his/her hand into another position. The farther the twist grip is turned, the more fuel is delivered to the combustion chambers) of the engine. Again, this applies in general to both engines with carburetors and engines having a mechanical or electronic fuel-injection system.

Vehicle 100 further comprises a first signal processing system 106 for determining a 15 level of fuel economy of engine 102 in operational use of vehicle 100 and for generating a control signal indicative of the fuel economy level determined. System 106 receives one or more input signals from one or more sensors 108. As mentioned above, such signal processing system and sensors are well known in the art and need not be discussed here in further detail.

In the invention the indicator, configured for indicating to a user of vehicle 100 the 20 level of the fuel economy, is implemented as follows. The indicator comprises an actuator 110 functionally coupled between first signal processing system 106 and accelerator device 104. Actuator 110 is configured for introducing a tactile signal into accelerator device 104 in dependence on a control signal received. In the example shown, first signal processing system 106 is a conventional signal processing system, whose output signal is indicative of the fuel 25 economy level. Conventionally, the output signal of system 106 is configured for control of a visual indication on the dashboard of vehicle. In the invention, a controller 112 is coupled between signal processing system 106 and actuator 110. Controller 112 is operative to convert the output signal from signal processing system 106 into a control signal of the proper format so as to be able to control actuator 110, depending on the format of the output signal supplied 30 by system 106 and on the type of actuator 110 used. Controller 112 can then be commercially offered as an after-market add-on. In another example, controller 112 forms an integral part of 8 known signal processing system 106 itself and can be re-programmed for supply of the properly formatted control signal to actuator 110.

Typically, the driver’s foot (in case of an automobile) or the rider’s hand (in case of a motorcycle) is practically continually in physical contact with accelerator device 104 in 5 operational user of vehicle 100. Accordingly, the tactile signals generated by actuator 110 are sensed by the driver being in contact with vehicle 100 through accelerator device 104.

A configuration interface 114 may be provided to enable the user or a mechanic to program or reprogram controller 112. For example, configuration interface 114 enables to modify an attribute of the tactile signal according to a preference of the user. An attribute of 10 the tactile signal may refer to one or more of: an intensity or amplitude of the tactile signal; a frequency of a vibratory tactile signal or another temporal aspect of the tactile signal such as duration; a change in resistance against moving accelerator device 104, a profile of the frequency and/or intensity in dependence of a magnitude of the fuel economy currently determined such as, for example, an increasing intensity of the tactile signal with decreasing 15 fuel economy according to a certain profile; etc.

Controller 112 and configuration interface 114 are indicated in the drawing as being components of a second signal processing system (or: control system) 116, which processes the output signal received from first signal processing system 106 in order to generate the control signal for supply to actuator 110.

20 In a further embodiment, second signal processing system 116 is configured for preventing the introduction of the tactile signal into accelerator device 104 if a rate of the change of the user-controllable position of accelerator device 104 has a magnitude larger than a pre-determined threshold. For example, a change of the user-controllable position is communicated to controller 112. If the change is larger than a predetermined threshold, 25 controller 112 stops supplying a control signal to actuator 110, thereby preventing the tactile signal from occurring in accelerator device 104. This feature becomes relevant when, e.g., the driver pushes the pedal or turns the twist grip quickly in order to accelerate. Preferably, the threshold is programmable or re-programmable via configuration interface 114.

In a further embodiment, actuator 110 is physically integrated with accelerator device 30 104.

9

Controller 112 comprises, e.g., a data processor or a microcontroller. Controller 112 may be an integral part of the vehicle’s onboard computer system (not shown separately) as supplied by the manufacturer. The onboard system takes care of, e.g., motor management tasks, providing status information about the vehicle to the driver, and that provides a user 5 interface to the user-controllable functions of vehicle 100. Controller 112 comprises computer code (not shown) with instructions as to how to process the signals input to controller 112. If controller 112 forms an integral part of the onboard computer system of vehicle 100, configuration user interface 114 may form an integral part of the user interface to the onboard computer system.

10 If controller 112 is a separate entity, controller 112 may have its own configuration interface 114 accommodated in a common housing. Configuration interface 114 provides, e.g., in a display monitor accommodated in the common housing, a menu of options for the driver or mechanic to select in order to configure operation of controller 112. Alternatively, controller 104 has a port, e.g., a USB port, to enable configuring controller 112 via a personal 15 computer (PC) or another data processing system.

Note that in an embodiment of the invention, first signal processing system 106 and second signal processing system 116 are combined into a single signal processing system onboard vehicle 100.

Fig.2 is a diagram 200 illustrating an attribute of the tactile signal introduced into 20 accelerator device 104 by actuator 110 under control of second signal processing system 116. The horizontal axis 202 indicates a numerical range of values “x” representative of the fuel economy level determined by first signal processing system 106. The higher the value of “x”, the more “x” lies to the right on axis 202, and the higher is the associated fuel economy level. The vertical axis 204 indicates a numerical range of numerical values “y” representative of a 25 magnitude of the attribute of the tactile signal, e.g., the magnitude of the intensity, the magnitude of the vibration frequency, etc. The higher up the value y lies on axis 204, the more pronounced or the higher is the magnitude of the attribute. Curve 206 indicates a dependence of the magnitude of the attribute on the level of fuel economy determined by system 106. In the example shown, the magnitude “y” of the attribute increases if the fuel economy level “x” 30 drops below a certain value X0. The magnitude “y” of the attribute increases to a maximum of “Yl” when the level “x” of the fuel economy drops to a value “XI”. If the level of fuel 10 economy drops below the value X1, the magnitude of the attribute drops to zero. This drop is relevant to a scenario wherein the driver wants to accelerate quickly. If the position of accelerator device 104 is changed quickly, controller 112 in second signal processing system 116 may provide only a tactile feedback for a very short time as the level of fuel economy 5 drops fast. This then has the function of signaling to the driver the “kick-down” function being activated in vehicle 100 that has an automatic transmission. The kick-down herein means depressing the accelerator pedal for rapid acceleration of vehicle 100. The kick-down increases the engine output, while simultaneously controls the down-shifting to the next lower gear to increase the output torque of engine 102.

10 Accordingly, the tactile signal as perceived by the driver becomes apparent with the fuel economy level dropping below a pre-determined threshold X0, and becomes more pronounced until the level XI has been attained. If the level of fuel economy drops further below level XI, the tactile signal as perceived by the driver disappears. The values of at least one of X0, XI and Y1 can be made programmable of re-programmable. The attribute may be a 15 frequency of a vibratory signal or an intensity of the vibratory signal, or any other suitable characteristic perceivable by the user. In an embodiment of the invention, the modality of the attribute is programmable or re-programmable, e.g., frequency or intensity or both. The dependence of the magnitude of the attribute on the level of fuel economy, i.e., curve 206 may be made dependent on, e.g., the road speed of vehicle 100, as determined by the vehicle’s 20 onboard signal processing system.

Accordingly, the invention relates especially to following embodiments:

Embodiment 1: A motor vehicle (100) comprising: an internal combustion engine (102) for propelling the motor vehicle; 25 an accelerator device (104) for controlling a change in fuel supply to the internal combustion engine in response to a change in a position of the accelerator device, the position being controllable by a user of the motor vehicle; a first signal processing system (106) for determining a level of fuel economy of the internal combustion engine during operational use of the motor vehicle; 30 a second signal processing system (116) for generating a control signal in dependence on the determined level; and 11 an indicator for indicating the determined level to the user of the motor vehicle; wherein the indicator comprises an actuator (110) functionally coupled between the second signal processing system and the accelerator device for introducing a tactile signal into the 5 accelerator device under control of the control signal.

Embodiment 2: The motor vehicle of embodiment 1, wherein the second signal processing system is configured for programming or reprogramming the dependence with respect to an attribute of the tactile signal.

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Embodiment 3: The motor vehicle of embodiment 1 or 2, wherein the second signal processing system is configured for preventing the introducing of the tactile signal into the accelerator device if a rate of the change of the position has a magnitude larger than a predetermined threshold.

15

Embodiment 4: The motor vehicle of embodiment 3, wherein the second signal processing system is configured for programming or reprogramming the pre-determined threshold.

20 Embodiment 5: The motor vehicle of embodiment 1, 2, 3 or 4, wherein the actuator is physically integrated with the accelerator device.

Embodiment 6: A second signal processing system (116) configured for supply of a control signal to an actuator (110) to generate a tactile signal in dependence on a level of fuel 25 economy of an internal combustion engine, for use in the vehicle of embodiment 1,2, 3,4 or 5.

Embodiment 7: A method of indicating, to a user of a motor vehicle (100) and during operational use of the motor vehicle, a level of fuel economy of an internal combustion engine 30 (102) of the motor vehicle, wherein: 12 the motor vehicle comprises an accelerator device (104) for controlling a change in fuel supply to the internal combustion engine in response to a change in a position of the accelerator device, the position being controllable by the user of the motor vehicle; and the method comprises: 5 determining the level of fuel economy during the operational use of the motor vehicle; generating a control signal in dependence on the level determined; and introducing a tactile signal into the accelerator device under control of the control signal.

10

Embodiment 8. The method of embodiment 7, further comprising preventing the introducing of the tactile signal into the accelerator device if a rate of the change of the position has a magnitude larger than a pre-determined threshold.

Claims

A motor vehicle (100) comprising: a combustion engine (102) for driving the motor vehicle; 5 a gas pedal or a throttle (104) for controlling a change in a supply of fuel to the combustion engine in response to a change in a position of the gas pedal or the throttle, the position being controllable by a user of the motor vehicle; a first signal processing system (106) for determining a level of fuel efficiency of the combustion engine during operational use of the motor vehicle; a second signal processing system (116) for generating a control signal in dependence on the determined level; and an indicator for indicating the determined level to the user of the motor vehicle; wherein the indicator comprises an actuator (110) operatively coupled between the second signal processing system and the accelerator pedal or the throttle for introducing, under the control of the control signal, a tactile signal into the accelerator pedal or into the throttle. 20

The motor vehicle of claim 1, wherein the second signal processing system is configured to program or reprogram the dependence on an attribute of the tactile signal.

The motor vehicle of claim 1 or 2, wherein the second signal processing system is configured to prevent the tactile signal from being introduced into the accelerator pedal or throttle lever if the change in position per unit time has a magnitude greater than a predetermined threshold.

The motor vehicle of claim 3, wherein the second signal processing system is configured to program or reprogram the predetermined threshold.

The motor vehicle of claim 1, 2, 3 or 4, wherein the actuator is physically integrated with the accelerator pedal or with the throttle.

6. A second signal processing system (116) configured to provide a control signal to an actuator (110) for generating a tactile signal in dependence on a level of fuel economy efficiency of an internal combustion engine suitable for use in the motor vehicle of claim 1, 2, 3, 4 or 5.

7. A method for indicating to a user of a motor vehicle (100) and during operational use of the motor vehicle, a level of fuel economy efficiency of a combustion vehicle combustion engine (102), wherein: the motor vehicle has an accelerator pedal or throttle (104) for controlling a change in a supply of fuel to the combustion engine in response to a change in a position of the gas pedal or the throttle, the position being controllable by a user of the motor vehicle; and the method comprises: determining the level of economy in fuel consumption during the operational use of the motor vehicle; generating a control signal in dependence on the determined level; and introducing a tactile signal into the mesh pedal or into the throttle control under the control of the control signal.

8. The method of claim 7, further comprising preventing the tactile signal from being introduced into the accelerator pedal or throttle if the change in position per unit time has a magnitude greater than a predetermined threshold.