Abstract:
A device for remotely changing the control of power generated by an internal combustion engine of a recreational vehicle driven by a driver controlling an accelerator pedal. The device includes a remote control, sending a signal for modulating the power and/or speed of the engine. The device comprises a system for measuring the position of the accelerator pedal, a system for receiving the signal for modulating the power and/or speed, a system for controlling the intake of gases into the engine, and an electronics module connected to the various systems, establishing rules for controlling the intake control system, depending on the position of the accelerator pedal and the received modulation signal.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the French patent application No. 1550301 filed on Jan. 15, 2015, the entire disclosures of which are incorporated herein by way of reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a device for the remote modification of the command for power and/or the speed of an internal combustion engine of a recreational vehicle. 
         [0003]    Karts are small, motorized vehicles which are lightweight and economical, which can be driven on circuits easily and with a high degree of safety. For a large number of people, these vehicles are a way of learning to drive during training sessions or races, as well as a pastime and leisure activity which can be pursued individually or in groups. 
         [0004]    Karts can be equipped with a two-stroke or four-stroke internal combustion engine. In this case, they have a fixed gear ratio transmission equipped with a clutch with launch control, or with a multi-ratio gearbox. There are also karts having an electric motor. 
         [0005]    It is known to install on karts a remote information unit, also called a “transponder”, which is a radio transmitter and receiver that responds to an external signal emitted by a fixed beacon in order to identify and locate the kart on the track, in order, in particular, to record lap times. 
         [0006]    In the case of an internal combustion engine, the driver has an accelerator pedal which is generally connected via a cable to a flap opening the gas passage of a carburetor, allowing it to control the quantity of fuel/air mixture admitted into the engine in order to adjust the power delivered. Kart engines can also be supplied by an injection system, in which case the driver issues a command for an air passage flap to be opened, this opening being measured by a computer which establishes the quantity of fuel to be injected. In order to remotely control the maximum speed of the kart, it is known to use a device comprising an electronic unit which is installed on the kart and is connected to the ignition system of the internal combustion engine in order to interrupt this ignition, or to modify the control prior to ignition, which is controlled remotely using a remote control operated by a track steward. 
         [0007]    The remote control can, in particular, impose a maximum speed for the kart, for example depending on the level of experience of the driver, or a deceleration profile for this kart, on its last lap in order to arrive in the pits at reduced speed in order to ensure safety, by commanding, at the electronic unit, successive ignition interruptions, or offsetting the advance, which limit the engine speed in accordance with what is desired. 
         [0008]    It is, in particular, possible to install fixed beacons in the ground in order to define deceleration zones which are noted by the electronic unit of the kart as it passes over them, in order to automatically command deceleration of the kart at this point in order to make arrival in the pits safer. 
         [0009]    However, this type of device which interrupts ignition while the driver is still trying to accelerate results in sudden, successive interruptions in the power delivered by the internal combustion engine, producing powerful and unpleasant vibrations. Changing the ignition advance results in improper combustion of the fuel and increased pollution. 
         [0010]    Furthermore, document U.S. Pat. No. 6,876,914 proposes a mechanical system for limiting the gas inlet flap opening in the internal combustion engine, which is controlled remotely by means of a remote control. This simply produces a change in the maximum power available, which leaves a first portion of the travel of the accelerator pedal useful, and renders the second portion of this travel inoperative. 
         [0011]    This changes the driving sensations experienced by the driver, with a very different accelerator pedal response. Furthermore, this system does not take into account the real operating conditions of the kart, in particular its speed. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention has, in particular, the aim of avoiding these drawbacks of the prior art. 
         [0013]    To that end, it proposes a device for the remote modification of the command for power delivered by an internal combustion engine of a recreational vehicle piloted by a driver acting on an accelerator pedal, comprising a remote control which sends a signal for modulating the power and/or the speed, this device comprising a system for measuring the position of the accelerator pedal, a system for receiving the signal for modulating the power and/or the speed, a system for regulating the gas inlet in the engine, and an electronic unit connected to these various systems, establishing rules for controlling the inlet regulation system depending on the position of the accelerator pedal and on the received signal for modulating the power and/or the speed. 
         [0014]    One advantage of this modification device is that it is easily possible, depending on the parameters contained in the signal sent by the remote control, to implement all sorts of curves adapting the response of the gas inlet opening by the servomotor, with respect to the position of the accelerator pedal, providing in particular reduced power and/or speed by limiting this opening, while avoiding sudden changes. 
         [0015]    Furthermore, it is also possible to keep the full range of movement of the accelerator pedal active, which provides the driver with a good driving sensation in spite of the gas inlet opening being limited, simply by modifying the proportional relationship between these two movements. 
         [0016]    The remote modification device according to the invention can further comprise one or more of the following features, which can be combined with one another. 
         [0017]    In particular, the modification device may comprise a system for measuring the speed of the internal combustion engine or the speed of the vehicle. 
         [0018]    In this case, the electronic unit may take into account the speed of the internal combustion engine or of the vehicle in order to establish the controlling rules. This makes it possible to implement precise closed-loop regulation of the top speed of the vehicle. 
         [0019]    Advantageously, the electronic unit establishes controlling rules using the full travel of the accelerator pedal to provide, over all of this travel, a continuously variable response of the gas inlet regulation system. The driving sensations then remain similar 
         [0020]    Advantageously, the electronic unit establishes controlling rules that change dynamically depending on received information. This makes it possible to incorporate in real-time parameters such as the position of the vehicle in order to modify the controlling rules. 
         [0021]    Preferably, the controlling rules may change depending on the position of the vehicle on a track. This makes it possible to automatically slow the vehicle in order to make safe, for example, a pit approach area or a section of the track. 
         [0022]    To that end, at least one beacon that is fixed with respect to the track (for example installed at the edge of the track) transmits a signal for modulating the power and/or the speed to at least one vehicle (and preferably to each vehicle) passing close to the beacon. 
         [0023]    Advantageously, the modification device comprises a servomotor for mechanically controlling a flap for the passage of inlet gases. 
         [0024]    Advantageously, the modification device comprises a system for measuring the position of the brake pedal. By detecting braking by the driver, it is possible to provide additional safety in the operation of the vehicle. 
         [0025]    Advantageously, the measurement systems comprising the positions of the accelerator pedal or the brake pedal, and the speed of rotation of the wheels, comprise Hall effect sensors. This type of sensor is simple and cost-effective. 
         [0026]    Advantageously, the system for receiving the modulation signal is integrated into the electronic unit. This makes use of a single unit integrating multiple common functions. 
         [0027]    Advantageously, the electronic unit comprises means for displaying information received during operation of the vehicle. It is possible to follow the operation during a session, either after-the-fact or in real-time from outside the vehicle. 
         [0028]    In this case, the electronic unit may comprise means for sending information to the remote control. 
         [0029]    The electronic unit may also comprise a port intended for connecting to an external computer, which makes it possible in particular to display information received during operation of the vehicle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Other features and advantages will emerge from the following description of the invention, which description is provided purely by way of example, with reference to the appended drawings, in which: 
           [0031]      FIG. 1  shows a kart driving on a track, equipped with a modulating device according to the invention; and 
           [0032]      FIG. 2  is a diagram of the connections of the electronic management unit of this device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0033]      FIG. 1  shows a kart  2  driving on a track  4 , piloted by a driver  6  acting on an accelerator pedal  8  located on the right, and on a brake pedal  10  located on the left. 
         [0034]    The internal combustion engine  12 , which is arranged at the rear and directly drives a transverse shaft connecting the two rear wheels, comprises a gas inlet regulation flap which is controlled by the accelerator pedal  8 . 
         [0035]    The kart  2  comprises an electronic management unit  14  which receives a power and/or speed modulation signal sent by a remote control  16  located at the edge of the track in order to command, depending on the position of the accelerator pedal  8 , a servomotor  24  that controls the gas inlet opening in order to remotely change the maximum power and/or the maximum speed delivered by the internal combustion engine  12 . 
         [0036]    The remote control  16  can be operated manually by a track steward, or automatically by a computer. 
         [0037]    Preferably, the electronic management unit  14  comprises, in addition to a system for receiving a signal, a system for transmitting a signal that can remotely send information to the remote control  16  or to another receiver. Preferably, the receiving and transmitting systems operate at the same power. According to one preferred embodiment, the electronic management unit  14  comprises a single transmitting and receiving system. 
         [0038]    In order to limit the electrical power consumption of the electronic management unit  14 , reception and transmission of signals is not permanent. 
         [0039]    According to one embodiment, the device comprises at least one fixed beacon  18  installed on, in or close to the track  4 . According to one embodiment, which is shown in  FIG. 1 , the device comprises multiple fixed beacons  18 ,  18 ′ which delimit a section of track  22 . Each fixed beacon  18 ,  18 ′ is configured to transmit a power and/or speed modulation signal to at least one kart  2  passing close to the fixed beacon  18 ,  18 ′. Preferably, each beacon is configured to transmit a power and/or speed modulation signal to each kart  2  passing close by. This makes it possible to regulate the power and/or the speed of each kart  2  for each section of the track, each section  22  being delimited by an upstream virtual line  20  and a downstream virtual line  20 ′, each corresponding to the passage of the karts  2  respectively close to a beacon  18  at the entrance to the section  22  and a beacon  18 ′ at the exit from the section  22 . 
         [0040]    According to one operating principle, each fixed beacon  18 ,  18 ′ transmits at least one short-range signal which can be picked up only by the karts passing close to the fixed beacon  18 ,  18 ′. 
         [0041]    The power and/or speed modulation signal transmitted by each fixed beacon  18 ,  18 ′ can be time-invariant. According to one preferred mode of operation, the power and/or speed modulation signal transmitted by each fixed beacon  18 ,  18 ′ varies. Thus, the remote control  16  can send, to at least one fixed beacon  18 ,  18 ′, a power and/or speed modulation signal that is transmitted by the fixed beacon  18 ,  18 ′ to at least one kart and preferably to all karts passing close to the fixed beacon  18 ,  18 ′. 
         [0042]      FIG. 2  shows the electronic management unit  14  connected to a set of electric wires forming multiple bundles, which will be described hereinbelow starting at the top. 
         [0043]    The first bundle A comprises two wires connected to two poles of an electrical power supply supplying direct current  32 . The electrical power supply can, in particular, provide a current at a nominal voltage of 12 V, which is in practice between 9 V and 14 V, with a maximum power of 20 W. 
         [0044]    The second bundle B comprises three wires connected to a pushbutton  34  (which comprises a switch  36 ) and to an indicator  38 . According to one mode of operation, the electronic management unit  14  comprises an auto switch-on system which can activate it when the engine  12  of the kart  2  is started up. If necessary, the pushbutton  34  can be used to activate the electronic management unit  14 . 
         [0045]    The third bundle C comprises three wires connected to a multiplexing network  40  for several functions of the kart, which can, in particular, use the “CAN bus” technology frequently used in motor vehicles. 
         [0046]    The third bundle C is connected to the multiplexing network  40  by electrical connections which are advantageously covered by a heat-shrinkable sleeve  52  in order to protect these connections. 
         [0047]    The fourth bundle D comprises three wires connected by two connection plugs  46  to a Hall effect braking sensor  42  which measures the displacement of a magnet  44  connected to the brake pedal  10  of the kart in order to register movements of this pedal commanded by the driver. It is possible, in particular, to detect a level of braking desired by the driver. 
         [0048]    Similarly, the fifth bundle E comprises three wires connected by two connection plugs  46  to a Hall effect acceleration sensor  48  which measures the displacement of a magnet  50  connected to the accelerator pedal  8  of the kart in order to register movements of this pedal commanded by the driver. 
         [0049]    In particular, the position of the accelerator pedal  8  is measured with sufficient precision to know the level of power desired by the driver. 
         [0050]    The sixth bundle F comprises three wires connected, by electrical connections advantageously covered by a thermo-adhesive sleeve  58  in order to protect these connections, to the servomotor  24  comprising a rotating disk  56  onto which can be attached a rod for controlling the gas inlet flap in the internal combustion engine. 
         [0051]    The gas inlet flap may be of various types. In particular, in the case of a carburetor, it can form a butterfly valve pivoting about an axis arranged in the gas passage, or a cylindrical or flat sliding gate which slides transversely with respect to this passage in order to close it. The gas inlet flap can also be a flap that controls only the ingress of air, in the case of an injection engine. 
         [0052]    The seventh bundle G comprises three wires connected by two connection plugs  46  to a Hall effect sensor  60  which detects the displacement of four magnets  62  distributed around the rear wheel shaft driven by the engine  12 . 
         [0053]    Thus, the frequency of the signal given by the magnets  62 , divided by the number of magnets, directly gives the speed of rotation of the shaft of the wheels. Then, taking into account the circumference of the rear wheels gives the speed of the kart. 
         [0054]    It is to be noted that this technology, arranging detection means directly on the wheel shaft, makes it possible to know the speed of the kart without using information from the ignition of the engine and giving the speed of this engine, which would not be sufficient in the case of a transmission comprising various gear ratios. 
         [0055]    As a variant, for a kart equipped with an engine having a single gear ratio, it is then possible to directly take the speed information of this engine, in particular at the ignition, and to obtain, taking into account the single reduction ratio, the rotational speed of the shaft of the wheels. 
         [0056]    The eighth bundle H comprises two wires. A first wire is connected by means of a plug  64  to the primary circuit of the high-voltage ignition coil of the engine, which provides information on the speed of this engine. A second wire comprises a ring terminal  66  which is designed to receive a screw for attachment to the mass of the engine, in order to earth the electronic management unit  14 . 
         [0057]    The electronic management unit  14  further comprises a port  74  that is intended to receive an adapter cable  70  comprising an end plug  72  which connects to a computer, in order to be able to read the information in this unit, or to program the unit. 
         [0058]    The electronic management unit  14  comprises a radio receiver that receives the modulation signal sent by the remote control  16 . 
         [0059]    Operation of the remote modification device is as follows. 
         [0060]    The electronic unit  14  comprises various programmed controlling rules, each resulting in a different response from the control of the servomotor  24 , and thus from the opening of the gas passage, depending on the position of the accelerator pedal  8  measured by the Hall effect acceleration sensor  48 . In particular, the programmed controlling rules can be dynamic in order to produce, for example, progressive braking of the kart over a defined zone, and if necessary stop it at a specific point. 
         [0061]    The operator or the computer in charge of the remote control  16  can thus exercise complete control, at a distance, of the power and/or the speed of the kart, in order in particular to ensure safety. 
         [0062]    During normal operation, when the function of remotely changing the power command is not activated, the electronic management unit  14  uses a normal controlling rule which controls a regular opening of the gas passage as a function of the degree to which the accelerator pedal  8  is pressed, such that this passage is fully open when the pedal is fully pressed. 
         [0063]    It will be noted that, between the two end positions of the accelerator pedal  8 , in which the gas passage is respectively essentially closed and completely open, the opening rule, which is not necessarily linear, can be freely adjusted in order to improve precision or comfort. 
         [0064]    The driver then has at their disposal the maximum power and/or speed of the motor, with no limitation. 
         [0065]    When the function of remotely changing the power and/or speed command is activated, the electronic management unit  14  uses various particular controlling rules of the servomotor  24 , which depend on the modulation signal sent by the remote control  16  located at the edge of the track. 
         [0066]    These include, in particular, the normal operating rule which allows the driver to use maximum engine power. These also include various controlling rules each applying one type of limitation, in particular a fixed limit on the maximum power or the speed of the internal combustion engine or of the kart, or a variable limit which restricts the power or the speed to a variable value, producing for example progressive deceleration prior to stopping. 
         [0067]    Advantageously, the controlling rules maintain variation in the power available over the entire travel of the accelerator pedal  8 , modifying the proportional relationship between this pedal travel and the permitted opening range of the gas inlet, in order to provide the driver with similar sensations using the full travel of the pedal. 
         [0068]    The limiting rule can be dynamic, changing in real time depending on received information, for example depending on the position of the kart in question or the positions of the other karts, or depending on external circumstances such as rain which reduces grip on the track. 
         [0069]    In particular, a beacon  18  can be used to impose a speed reduction on the karts passing close to the beacon  18 . It is also possible to use action on the brake pedal  10 , measured by its sensor  42 , to limit the power delivered by the internal combustion engine  12  in order to avoid incorrect maneuvers. 
         [0070]    The control of the servomotor  24  can, in particular, take into account, in return, reactions of the kart measured in real time, in particular the speed of the internal combustion engine  12  or the speed of this kart, in order to carry out closed-loop regulation involving correction of the setpoint given to the servomotor  24 , in order to obtain the corresponding control of the gas inlet at a desired speed. 
         [0071]    Furthermore, the remote modification device can also propose another function which requires no additional material, is cost-effective and provides, in real time or after the fact, information on the operation of the kart, which is recorded by the electronic unit  14 . 
         [0072]    This information can be read after the fact by connecting a computer to the port  74  of the electronic unit  14 , after the kart has been driven. It can also be transmitted in real time by the electronic unit  14  comprising a transmitter, to be read by the operator or the computer in charge of the remote control  16 . 
         [0073]    Connecting a computer to the port  74  also makes it possible to reprogram the electronic unit  14 . 
         [0074]    This makes it possible to receive and record information on the operation of each kart on the track, in particular its maximum speed or power, or its speed profile around the circuit. This function can serve, for example, to check the state of the karts, or can be used as a teaching resource to help the drivers improve. 
         [0075]    It will be noted that the device for the remote modification of the power and/or speed command, according to the invention, can be used in various types of vehicles driving in a given location, such as all-terrain karts, or other types of four-wheeled or two-wheeled vehicles which comprise regulation of the gas inlet in the engine, and which can go around a track. 
         [0076]    As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.