Method and control system for a hybrid motor vehicle based on traffic lights

Abstract

A method for controlling a hybrid motor vehicle comprises the following steps: in a first step (1), information is received from the traffic lights; in a second step (2), the active signal displayed and the time until the signal change of the first traffic light on the vehicle's path are determined based on the traffic light information; and in steps (3, 4, 5, 6, 7, 8), the time until the signal change of the traffic light, the vehicle speed, and the maximum authorized speed on the roadway used by the motor vehicle are compared, then the energy management law is controlled and the driver is instructed on actions to perform in order to limit the waiting time at the traffic light and the energy expended between passing the traffic light and passing through it. Figure for the abstract: Fig 1

Description

Title of the invention: Method and system for controlling a hybrid motor vehicle based on traffic lights Technical field

[0001] The technical field of the invention is the control of motor vehicles, and in particular, the control of such vehicles equipped with a hybrid powertrain.

[0002] In order to optimize the energy consumption of vehicles, it is possible to avoid stops or decelerations when approaching a traffic light signaling a mandatory stop, to anticipate the passage from traffic lights to a signal signaling a mandatory stop in order to cut off the injection of the thermal engine or to limit the operation of the electric motor, or even to let the vehicle move at idle. To do this, it is necessary to know in advance the chronology of the change of state of the traffic lights (timing of the passages between the signal states).

[0003] For a hybrid vehicle comprising a thermal engine and at least one electric motor, the route, the speed profile and the power demand at the wheel make it possible to optimize overall consumption as much as possible. With new technologies, it is possible to have information on the future, in particular on the state and the duration before changing the traffic lights.

[0004] In manual mode, only the driver decides on the vehicle's acceleration and deceleration by reading the advice displayed on the dashboard when approaching a traffic light.

[0005] On the other hand, the hybrid supervisor controls the thermal engine and Ic / lcs electric motors in torque, as well as the stopping and starting of the thermal engine.

[0006] There is a need for optimization of the energy management law based on the state of the traffic lights on the vehicle's path. Previous techniques

[0007] From the state of the prior art, we know the document FR2101753 describing a method of controlling an automated gearbox which allows, when the driver does not respect the instruction given when approaching a traffic light, to strongly encourage him to do so by cleverly controlling the gearbox.

[0008] This document is applicable to any vehicle with an automated gearbox, with the aim of avoiding unnecessary overconsumption of fuel linked to the driver's behavior. However, it does not describe the application to a hybrid vehicle and the consideration of several driving sources. Statement of the invention

[0009] The subject of the invention is a method for controlling a motor vehicle provided with of a hybrid powertrain comprising a heat engine and at least one electric machine, governed by a predetermined energy management law and the vehicle further comprising a computer, a human-machine interface for displaying information to the driver and means of communication with at least one traffic light, the method comprising the following steps: the computer receives information from a traffic light, the computer determines the distance to the traffic light, the active signal displayed by the traffic light from among a first signal associated with a crossing authorization and a second signal associated with a crossing prohibition, and a duration until the signal of the traffic light changes as a function of said information received, the computer compares the duration until the signal of the traffic light changes with a duration to cover the distance to the traffic light,the computer temporarily modifies the energy management law based on the result of the comparison and sends an indication to the driver of at least one action to be carried out, consistent with said modification of the energy management law, so as to limit the energy expended until the traffic light is crossed.

[0010] When the traffic light displays the second signal and when the time to cover the distance to the traffic light at the current speed of the vehicle is less than the time until the signal change, itself less than the time required for the vehicle to cover the distance to the traffic light in freewheel mode, the computer can temporarily modify the energy management law to adapt the regenerative braking according to the distance to the traffic light, and the computer can send an indication to the driver to release the accelerator pedal.

[0011] When the traffic light displays the first signal and when the time until the signal change is greater than the time to cover the distance to the traffic light at the current vehicle speed, the computer may temporarily modify the energy management law so as to maintain the required wheel speed, preferably in all-electric mode, and the computer may send an indication to the driver to maintain at least the current vehicle speed.

[0012] When the traffic light displays the first signal and when the time to cover the distance to the traffic light at the current speed of the vehicle is greater than the time taken until the signal changes, itself greater than the time to cover the distance to the traffic light at the maximum authorized speed, the computer can temporarily modify the energy management law so that the heat engine is started, if it was stopped, and kept running until the traffic light is crossed in order to provide additional power. additionally, and the calculator can send an indication to the driver of the maximum authorized speed to be reached.

[0013] When the traffic light displays the first signal and when the time to cover the distance to the traffic light at the maximum authorized speed is greater than the time until the signal change, the computer can temporarily modify the energy management law so as to force an all-electric operating mode to carry out regenerative braking, and the computer can send an indication to the driver to release the accelerator pedal.

[0014] When the traffic light displays the second signal, and when the time until the signal change is less than the time to cover the distance to the traffic light at the current speed of the vehicle, the computer may not modify the energy management law and, the computer may send an indication to the driver to keep the speed of the vehicle unchanged, so that the vehicle passes the traffic light while it will display the first signal, after a change from the second signal.

[0015] When the traffic light displays the second signal and when the time required for the vehicle to travel the distance to the traffic light using engine braking is less than the time until the signal changes, the computer can modify the energy management law so as to force an all-electric mode and adapt the regenerative braking and, the computer can send an indication to the driver of a recommended speed and to release the accelerator pedal, so as to minimize the energy expenditure because the vehicle will reach the traffic light while it displays the second signal, before a signal change.

[0016] When crossing the traffic light, the computer can suppress the indications to the driver and the temporary modification of the energy management law ends.

[0017] When crossing several traffic lights is planned on the route, the computer can temporarily modify the energy management law when passing a first traffic light in order to force a discharge of the battery to retain the possibility of carrying out regenerative braking when passing the following traffic lights.

[0018] The invention also relates to a system for controlling a motor vehicle equipped with a hybrid powertrain, a human-machine interface for displaying information to the driver, means of communication with at least one signal light and control means configured to carry out the control method as described above.

[0019] An advantage of the method and the control system lies in the reduction of the energy consumption of hybrid vehicles in urban environments, when

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[0034] has knowledge of traffic light changes. The powertrain management law makes it possible to optimize energy consumption by knowing the actions to be carried out in the near future as well as the associated power demand. Brief description of the drawings Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example and made with reference to the appended drawings in which: - figure [Fig.l] illustrates the main steps of a control method according to the invention. Detailed description There are two states of a traffic light. The first state is a permitted passage. In most countries, this state corresponds to a green light. The second state is a mandatory stop. In most countries, this state corresponds to a red light. The following notations are defined. 0 if passage is prohibited: the state of the traffic light Ef=\ 1 if passage is authorized Tcc; the time until signal change D; the distance between the traffic light and the vehicle VeSo: vehicle speed VUm: the maximum speed authorized on the road used TVÿÿo — D / Vego: the time taken to cover the distance to traffic light D at the current vehicle speed Vego T * = D / Vf- : the time taken to cover the distance to traffic light D at the maximum authorized speed V um. Tfm: the time taken by the vehicle to cover the distance to traffic light D using engine braking. T mailing: the time required for the vehicle to travel the distance to traffic light D in freewheel mode (known as “sailing” mode in English). The hybrid powertrain's state changes based on driver input via the accelerator pedal, vehicle speed, and battery status. The method for controlling a hybrid motor vehicle equipped with a hybrid powertrain comprising a thermal engine and at least one electric machine is carried out by means of an on-board computer comprising a memory and a processor configured to execute the steps described below.

[0035] The hybrid powertrain includes several operating modes.

[0036] In a first mode of operation, only the electric machines generate torque at the wheel. The thermal engine does not participate. In a hybrid vehicle, the thermal engine is systematically switched off.

[0037] In a second operating mode, the thermal engine and the electrical machines generate a torque at the wheel depending in particular on the driver's request, the power that can be generated by each component, the available fuel, the state of charge of the traction battery, in a manner known from the state of the art.

[0038] In a hybrid mode, the electric machines can be motors to provide additional power to the wheels or, on the contrary, generators to recharge the batteries.

[0039] In a third operating mode, the thermal engine is the only one to supply torque to the wheel. This is particularly the case when the traction battery has a state of charge that is too low to allow the electric machines to be powered. A too low state of charge of the battery can also result from the optimization of the energy on board the vehicle.

[0040] The control method is illustrated by the figure [Fig. 1] and comprises a first step 1 of determining the information relating to the traffic lights. This information is acquired via a vehicle-to-infrastructure V2I type communication.

[0041] The state of a traffic light includes its current state (the color of the light) Ef and the time remaining before the next change of state of the traffic light Tcc. The geographical position of the traffic light, and the controlled lanes can also be part of the state of a traffic light. The position of the light and the lane concerned are given to calculate the distance to the vehicle and whether the vehicle is concerned by the lane it is using.

[0042] During this same first step 1, the information to be taken into account is determined as a function of the distance between the vehicle and each traffic light, as a function of the trajectory planned over a predetermined time horizon T, for example 15 s.

[0043] In a particular embodiment, the probable trajectory is taken into account as a function of the direction of travel, and of the signaling plan around the motor vehicle.

[0044] During a second step 2, the active signal displayed by the first traffic light on the vehicle's path is determined.

[0045] When the traffic light displays a first signal and will display a second signal in the duration until the signal change Tcc and if Tcc > Tv the process continues with a third step 3. It is estimated that at the current speed Vego, the vehicle will pass the traffic light while it displays a first signal, before changing to a second signal. The vehicle speed is then kept unchanged. The energy management law is modified so as to maintain the speed and power required by the wheels. If all-electric operation meets this requirement, the combustion engine is not started.

[0046] The driver is instructed to maintain his speed.

[0047] When the traffic light displays a first signal and will display a second signal in the duration until the signal change Tcc and if TVeoo > Tcc > T, the method continues with a fourth step 4. It is estimated that at the current speed, the vehicle will reach the traffic light while it displays a second signal. On the other hand, by accelerating to the maximum authorized speed, the vehicle will pass the traffic light while it displays a first signal, before a change to a second signal.

[0048] The all-electric operating mode may be insufficient. The energy management law is then modified in order to start the thermal engine to provide additional power. The energy management law is also modified so as to prohibit the stopping of the thermal engine.

[0049] The driver is told the speed to be reached.

[0050] When the traffic light displays a first signal and will display a second signal in the duration until the signal change Tcc and if Tv* > Tcc, the method continues with a fifth step 5. It is estimated that, even at the maximum authorized speed, the vehicle will reach the traffic light while it displays a second signal.

[0051] The driver is then instructed to release the accelerator pedal. If the traction battery is not fully charged, the energy management law is modified so that the all-electric operating mode is forced, to carry out regenerative braking.

[0052] When the traffic light displays a second signal and will display a first signal in the duration until the signal change Tcc, and if Tcc < T y the method continues with a sixth step 6. It is estimated that at the current speed, the vehicle will pass the traffic light while it displays a first signal, after a change from a second signal. The vehicle speed is then ordered to remain unchanged and the energy management law is modified so that the operating mode of the powertrain remains unchanged. In particular, the operating mode can remain all-electric if the power supplied is sufficient, otherwise the hybrid operating mode (second operating mode) is engaged.

[0053] Hybrid mode engaged: thermal engine start and mode maintained (no action on clutch, gearbox, etc.) no change in the state of the powertrain.

[0054] When the traffic light displays a second signal and will display a first signal in the duration until the signal change Tcc, and if Tv < Tcc < Tsaiiing, the The process continues with a seventh step 7. It is estimated that at the current speed, the vehicle will reach the traffic light while it is displaying a second signal, before a signal change. On the other hand, by switching to freewheel mode ("sailing" in English), the vehicle will pass the traffic light while it is displaying a first signal, after a signal change.

[0055] The vehicle is controlled so that it moves in freewheel mode. In other words, if it was active, the injection is cut off and the vehicle moves only under the effect of its own inertia and is slowed down only by aerodynamic drag, tire resistance and the rolling resistance of the vehicle. The driver is told to release the accelerator pedal. When freewheeling on a hybrid vehicle, the thermal engine is switched off and if possible the electrical machine(s) are disconnected to limit losses.

[0056] The energy management law is modified so that the all-electric operating mode is forced, the thermal engine then being stopped. The energy management law is also modified so as to adapt the regenerative braking to reach the set speed. Finally, when the traction battery is too discharged and the stopping phase of the thermal engine is too short, then the latter is kept at idle.

[0057] This is a hybrid mode in which the electric machine is used in generator mode. Stopping / starting the thermal engine is not profitable if it is too short.

[0058] When the traffic light displays a second signal and will display a first signal in the duration until the signal change Tcc, and if Tfm < T cc, the method continues with an eighth step 8. It is estimated that even in engine braking mode, the vehicle will reach the traffic light while it displays a second signal, before a signal change.

[0059] The driver is told to set a recommended speed and to release the accelerator pedal.

[0060] The energy management law is modified so as to impose an operation of the vehicle in all-electric mode in order to benefit from regenerative braking. The mechanical brake is then used in addition.

[0061] At the end of steps 3 to 8, the method ends in a ninth step 9 when crossing the traffic light, during which the information is deleted. displayed to the driver and all operating modes of the hybrid powertrain are authorized. The process then resumes at step 1 considering the next traffic light.

[0062] When there are several traffic lights, the energy management law can be modified when passing a first traffic light in order to force a discharge of the battery to maintain the possibility of carrying out regenerative braking when passing the following traffic lights.

Claims

Claims

1. Method for controlling a motor vehicle equipped with a hybrid powertrain comprising a thermal engine and at least one electric machine, governed by a predetermined energy management law, the vehicle further comprising a computer, a human-machine interface for displaying information to the driver and means of communication with at least one traffic light, the method comprising the following steps: - the calculator receives information from a traffic light, - the calculator determines the distance to the traffic light, the active signal displayed by the traffic light from among a first signal associated with a crossing authorization and a second signal associated with a crossing prohibition, and a duration until the signal of the traffic light changes according to said information received, - the calculator compares the duration until the signal of the traffic light changes with a duration to cover the distance to the traffic light, - the computer temporarily modifies the energy management law based on the result of the comparison and sends an indication to the driver of at least one action to be carried out, consistent with said modification of the energy management law, so as to limit the energy expended until the traffic light is crossed, - when crossing several traffic lights is planned on the route, the computer temporarily modifies the energy management law when passing the first traffic light in order to force a discharge of the battery to maintain the possibility of carrying out regenerative braking when passing the following traffic lights.

2. A method of controlling a motor vehicle according to claim 1, wherein, when the traffic light displays the second signal and when the time to cover the distance to the traffic light at the current vehicle speed is less than the time until the signal changes, itself less than the time required for the vehicle to cover the distance to the traffic light while coasting, the computer temporarily modifies the energy management law to adapt the regenerative braking according to the distance to the traffic light. lization, and the computer sends an indication to the driver to release the accelerator pedal.

3. A method of controlling a motor vehicle according to any one of claims 1 to 2, wherein, when the traffic light displays the first signal and when the time until the signal change is greater than the time to cover the distance to the traffic light at the current vehicle speed, the computer temporarily modifies the energy management law so as to maintain the required wheel speed, preferably in all-electric mode, and the computer sends an indication to the driver to maintain at least the current vehicle speed.

4. A method of controlling a motor vehicle according to any one of claims 1 to 3, wherein, when the traffic light displays the first signal and when the time to cover the distance to the traffic light at the current speed of the vehicle is greater than the time until the signal change, itself greater than the time to cover the distance to the traffic light at the maximum authorized speed, the computer temporarily modifies the energy management law so that the heat engine is started, if it was stopped, and kept running until the traffic light is crossed in order to provide additional power, and the computer sends an indication to the driver of the maximum authorized speed to be reached.

5. A method of controlling a motor vehicle according to any one of claims 1 to 4, wherein, when the traffic light displays the first signal and when the time to cover the distance to the traffic light at the maximum authorized speed is greater than the time until the signal changes, the computer temporarily modifies the energy management law so as to force an all-electric operating mode to carry out regenerative braking, and the computer sends an indication to the driver to release the accelerator pedal.

6. A method of controlling a motor vehicle according to any one of claims 1 to 5, wherein, when the signal light displays the second signal, and when the time until the signal change is less than the time to cover the distance to the traffic light at the current vehicle speed, the computer does not change the energy management law and, the computer sends an indication to the driver to keep the vehicle speed unchanged, so that the vehicle passes the traffic light while it will display the first signal, after a change from the second signal.

7. A method of controlling a motor vehicle according to any one of claims 1 to 6, wherein when the traffic light displays the second signal and when the time required for the vehicle to travel the distance to the traffic light using engine braking is less than the time until the signal changes, the computer temporarily modifies the energy management law so as to force an all-electric mode and adapts the regenerative braking and, the computer sends an indication to the driver of a recommended speed and to release the accelerator pedal, so as to minimize the energy expenditure because the vehicle will reach the traffic light while it displays the second signal, before a signal change.

8. Method for controlling a motor vehicle according to any one of claims 1 to 7, in which, when crossing the traffic light, the computer removes the indications to the driver and the temporary modification of the energy management law ends.

9. Control system for a motor vehicle equipped with a hybrid powertrain, a human-machine interface for displaying information to the driver, means of communication with at least one traffic light and control means configured to carry out the control method as claimed in the preceding claims 1 to 8.

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