Method for optimizing energy consumption of vehicle
By implementing a method connecting the road infrastructure management system in a computer in a vehicle, the optimal speed curve of the vehicle is calculated to optimize energy consumption, and the problem of failure to effectively consider the individual energy consumption of the vehicle in the prior art is solved, and the problem of realizing that the vehicle is not fully considered in the prior art is realized. Optimization of vehicle energy consumption and synchronization of road infrastructure.
Patent Information
- Application Number
- CN202380045234.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-08
- Filing Date
- 2023-07-04
- Publication Date
- 2025-02-14
AI Technical Summary
The prior art fails to effectively consider the individual energy consumption of each vehicle in optimizing vehicle energy consumption, focusing only on the overall traffic flow, resulting in the vehicle's potential failure to minimize energy consumption when passing through traffic lights.
By implementing a method in a computer on-board in a vehicle connected to a system that manages road infrastructure and traffic-related data, the optimal speed curve for the vehicle is calculated so that energy consumption is minimal when reaching the next road infrastructure element and synchronize with the stage or state of the road infrastructure. The method includes multiple computing modes to adapt to the state of different road infrastructure elements and the actual situation of the vehicle.
The optimal energy consumption of the vehicle when it reaches the next road infrastructure element is achieved, reducing the vehicle's fuel and electricity consumption, while providing optimal time synchronization with the road infrastructure, improving driving comfort.
Smart Images
Figure CN119451875A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for optimizing the energy consumption of a vehicle. The method is implemented in a computer on board the vehicle. The invention also relates to a method for controlling the speed of a vehicle, the method being implemented in a computer on board the vehicle, the method comprising such a sub-method for optimizing the energy consumption of the vehicle. The invention also relates to: a computer on board the vehicle, the computer comprising means for implementing the steps of such a method for optimizing the energy consumption of the vehicle; and a vehicle, in particular a motor vehicle, having such an on-board computer. The vehicle is typically, but not exclusively, an autonomous or semi-autonomous vehicle. Finally, the invention relates to a computer program product comprising program instructions configured to implement the steps of such a method for optimizing the energy consumption of a vehicle. Background Art
[0002] In the field of optimal vehicle control, it is known to adapt the speed profile of the vehicle according to the various traffic lights that are predicted to be ahead of the vehicle during its journey. A known solution, called "predicted green wave", consists in coordinating the speed of the vehicle and / or the phase of the traffic lights so that when the vehicle arrives at each successive traffic light it is green (or in an "open" state). The vehicle then does not need to stop and can therefore pass each traffic light at a non-zero speed. To this end, the vehicle must be connected to a system for managing static and / or dynamic data related to the road infrastructure and / or road traffic, and the traffic lights must have a predictable operating cycle or state change cycle. Such a management system is, for example, constructed in a cloud architecture and makes it possible to provide (or even predict) the time range of the operating cycle (or state change cycle) of the traffic traffic lights detected as being ahead of the vehicle during its journey, in particular according to the speed of the vehicle and the traffic density on the road. The "operating cycle" or "state change cycle" of a traffic light tends to mean the respective durations of the "green", "yellow" and "red" phases or states of said traffic light, which are assumed to form a repetitive repeating cycle with a constant period, or a cycle that can be predicted based on other known parameters (such as, for example, time, location, town or type of road or intersection). The "phase" or "state" of a traffic light tends to mean the current color of light emitted by said traffic light and the duration of the emission of said color light (e.g., "red" in the next five seconds, or "green" in the next eight seconds, etc.). The document "Green Wave Traffic Theory Optimization and Analysis" (World Journal of Engineering and Technology, February 2014, pages 14-19) describes, for example, such a "predicted green wave" solution.
[0003] In this "predictive green wave" solution, the speed of the vehicles is calculated as a constant value (or average value), wherein the different schedules of arrival at the lights are synchronized so that each vehicle arrives at each light when it is green (thus making it possible to minimize or even eliminate the phases of slowing down or stopping before red lights). The speed of the vehicles is calculated so that the vehicles arrive at each light when it is green, based solely on the time criterion. However, a drawback of this solution is that it does not take into account the criterion of minimizing the individual energy consumption (fuel and / or electricity from batteries) of each vehicle. Only the overall traffic flow is taken into account, which is usually done in order to synchronize the schedules and to reduce the fuel consumption corresponding to the fleet in general. Summary of the invention
[0004] Therefore, a method for optimizing the energy consumption of a vehicle is needed, making it possible for the vehicle to calculate the best speed profile to follow (in terms of minimizing the energy consumption of the vehicle) in order to reach the next road infrastructure element (acceleration or deceleration, average speed, braking phase, etc.), while covering the distance from the current position of the vehicle to said element and providing an optimal time synchronization with the phases or states of the road infrastructure element (and the best possible driving comfort when the vehicle is not autonomous). "Road infrastructure element" is intended to mean, for example, a road traffic light, a railway level crossing or a tram track crossing, or any other infrastructure element having a first open or passable state and a second closed or stopped state.
[0005] To this end, the invention in its broadest sense also relates to a method for optimizing the energy consumption of a vehicle, the method being implemented in a computer on board a vehicle, the computer of the vehicle being connected to a system for managing static and / or dynamic data relating to road infrastructure and / or road traffic, said static and / or dynamic data comprising status data relating to at least one road infrastructure element having a first open or passable state and a second closed or stopped state, said road infrastructure element operating alternately between its first state and its second state according to a fixed, predetermined and predictable operating cycle, said operating cycle as well as said other static and / or dynamic data relating to the road infrastructure and / or road traffic being supplied as input to the computer, the vehicle being further provided with a navigation and positioning system of the vehicle connected to the computer, the route of the vehicle within a predetermined distance being predefined or predicted in the computer, the computer being configured to calculate an optimal speed profile for the vehicle according to a predefined calculation method, said calculation method being configured to make it possible to minimize the energy consumption of the vehicle, the method comprising the following steps:
[0006] - determining the distance between the vehicle and the next road infrastructure element located on the route of the vehicle;
[0007] - calculating an optimal speed profile for the vehicle as a function of the determined distance in a first calculation mode of the calculation method, in which first calculation mode the speed of the vehicle at the moment of arrival at said road infrastructure element and the time of arrival of the vehicle at the road infrastructure element are unconstrained, the state of the road infrastructure element at the moment of arrival of the vehicle at the road infrastructure element being assumed to be a first open or passable state;
[0008] - calculating the time of arrival of the vehicle at said road infrastructure element according to the calculated optimal speed profile;
[0009] - determining the state of the road infrastructure element at the moment of arrival of the vehicle at the road infrastructure element based on the calculated time and the operating cycle of the road infrastructure element;
[0010] - comparing said determined state with a first opening or trafficable state of the road infrastructure element;
[0011] - if said determined state of the road infrastructure element corresponds to a first open or passable state, the computer takes into account the optimal speed profile for the vehicle calculated according to the first calculation mode in order to apply or recommend said optimal speed profile to the vehicle;
[0012] If said determined state of the road infrastructure element does not correspond to a first open or trafficable state:
[0013] calculating an optimal speed profile for the vehicle according to the determined distance in a second calculation mode of the calculation method, in which second calculation mode the speed of the vehicle at the moment of arrival at said road infrastructure element is fixed at a zero value and supplied as an input to the calculation method, and the time of arrival of the vehicle at the road infrastructure element is unconstrained, the state of the road infrastructure element at the moment of arrival of the vehicle at the road infrastructure element being assumed to be a second closed or stopped state;
[0014] o calculating the time for the vehicle to arrive at the road infrastructure element according to the calculated optimal speed profile;
[0015] o determining the state of the road infrastructure element at the moment of arrival of the vehicle at the road infrastructure element based on the calculated time and the operating cycle of the road infrastructure element;
[0016] o comparing the determined state with a second closed or stopped state of the road infrastructure element;
[0017] o if said determined state of the road infrastructure element corresponds to a second closed or stopped state, the computer taking into account an optimal speed profile for the vehicle calculated according to a second calculation mode in order to apply or recommend said optimal speed profile to the vehicle;
[0018] o If said determined state of the road infrastructure element does not correspond to a second closed or stopped state:
[0019] ■ calculating an optimal speed profile for the vehicle according to the determined distance in a third calculation mode of the calculation method, in which third calculation mode the speed of the vehicle at the moment of arrival at said road infrastructure element is unconstrained and the time of arrival of the vehicle at the road infrastructure element is fixed to the time at which the road infrastructure element switches to a next first open or passable state reachable by the vehicle, said time being supplied as an input to the calculation method, the road infrastructure element being assumed to have just switched to its first open or passable state at the moment of arrival of the vehicle at the road infrastructure element;
[0020] ■ The computer takes into account the optimal speed profile of the vehicle calculated according to the third calculation mode in order to apply or recommend the optimal speed profile to the vehicle.
[0021] In the remainder of this description, "reachable" is intended to mean that the road infrastructure element is located at a distance from the vehicle such that the vehicle can reach it in its intended state, ie a first open or passable state or a second closed or stopped state.
[0022] The method according to the invention comprises a set of successive optimization steps, the purpose of which is to determine the optimal speed profile in order to cover the distance between the current position of the vehicle and the next road infrastructure element, while minimizing the energy consumption criterion of the vehicle. Thus, the method according to the invention alternately implements different optimization (or calculation) modes depending on the verification of certain conditions or their opposites (verification according to certain predefined assumptions). The purpose is to expect the upcoming state or phase of the road infrastructure element so that the road infrastructure element is in its open or passable state when the vehicle passes it, or in its closed or stopped state when it stops at it, and the energy cost is at a minimum. In each of these steps, the optimal speed profile of the vehicle is calculated in order to obtain the minimum energy consumption during the journey from the current position of the vehicle to the position of the next road infrastructure element to be reached on the route in one of the optimization (or calculation) modes stated above. As soon as the vehicle detects the next road infrastructure element (the distance to which is known and the phase or state of this element in its cycle or operating period is known), the different steps of the method are calculated as quickly as possible in the on-board computer.
[0023] The method according to the invention thus makes it possible to calculate the optimal speed profile to be followed by the vehicle in order to reach the next road infrastructure element, while covering the distance from the current position of the vehicle to said element. The method provides an optimal time synchronization with the phase or state of the road infrastructure element (at the moment of the vehicle's arrival at said element), while making it possible to minimize the energy consumption of the vehicle.
[0024] Advantageously, the method further comprises the following: a step of calculating an optimal speed profile for the vehicle according to the determined distance in a fourth calculation mode of the calculation method, implemented when none of the steps of calculating an optimal speed profile for the vehicle gives an acceptable solution for the vehicle, in which fourth calculation mode the speed of the vehicle at the moment of reaching said road infrastructure element is fixed at a value of zero and the time of the vehicle's arrival at the road infrastructure element is fixed to the time at which the road infrastructure element switches to the next second closed or stopped state, said speed of the vehicle and said time being supplied as inputs to the calculation method, the road infrastructure element being assumed to have just switched to its second closed or stopped state at the moment of the vehicle's arrival at the road infrastructure element; and a step of the computer taking into account the calculated optimal speed profile for the vehicle in order to apply or recommend said optimal speed profile to the vehicle. This makes it possible to supply an optimal vehicle speed calculation for all conceivable situations, even when none of the first, second and third calculation modes of the method gives an acceptable solution for the speed profile to be followed by the vehicle. If the time to reach a road infrastructure element when it is in its open or passable state is too long or too short, the solution provided by this fourth calculation mode is to accept the vehicle parked at the road infrastructure element when it is in its closed or stopped state, with less energy savings.
[0025] Advantageously, the vehicle further has on-board means for measuring or estimating the distance between the vehicle and another vehicle immediately preceding the vehicle and / or means for measuring or estimating the relative speed of said other vehicle, said measuring or estimating means being connected to a computer, and the method further comprises the following: a step of detecting at least one other vehicle on the route of the vehicle, said at least one other vehicle moving in the same direction as the vehicle and being located between the vehicle and the next road infrastructure element; and a step, carried out in the event of the detection of at least one such other vehicle, consisting in determining the distance between the vehicle and said such other vehicle immediately preceding it on the route of the vehicle, and then, before the first calculation step, replacing the determined distance between the vehicle and the next road infrastructure element with said distance between the vehicle and said such other vehicle immediately preceding it on the route of the vehicle. This makes it possible to take into account the presence of at least one other vehicle moving in the same direction as the vehicle and being located between the vehicle and the next road infrastructure element, and thus avoid the risk of collision between the vehicle and said at least one other vehicle. According to a particular technical feature of the invention, the relative speed of other vehicles is estimated, for example, by an on-board computer based on the operating cycle of the road infrastructure element and a model of the vehicle's reaction when the road infrastructure element switches from its closed or stopped state to its open or passable state and vice versa (the model may, for example, be pre-recorded, or based on prediction equations, or based on any other mechanism, etc.).
[0026] Advantageously, the method further comprises a phase of detecting at least one predetermined condition or at least one predetermined event, and if at least one such predetermined condition or one such predetermined event is detected, the method loops back to the step of determining the distance between the vehicle and the next road infrastructure element situated on the route of the vehicle taking into account the new current position of the vehicle. This makes it possible to take into account any events (such as interruptions on the route of the vehicle) or any deviations of the actual speed of the vehicle and / or the state of the next road infrastructure element from the prediction made, which may have occurred before the vehicle reaches said road infrastructure element.
[0027] According to a specific technical feature of the present invention, the predefined calculation method is a calculation method that implements the Pontryagin maximum principle.
[0028] According to another technical feature of the invention, the at least one road infrastructure element is a road traffic signal, such as a two-color or three-color signal. The open or passing state then corresponds to a green light emitted by the traffic signal. The closed or stopped state in turn corresponds to a red light emitted by the traffic signal. When the road infrastructure element is a railway level crossing or a tram track crossing, the open or passing state may correspond to a lack of light emission (or an obstacle raised), and the closed or stopped state may correspond to, for example, a flashing light (or a lowered obstacle).
[0029] The invention also relates to a method for controlling the speed of a vehicle, the method being implemented in a computer on board a vehicle, the computer of the vehicle being connected to a system for managing static and / or dynamic data relating to a road infrastructure and / or road traffic, the static and / or dynamic data comprising status data relating to at least one road infrastructure element having a first open or passable state and a second closed or stopped state, the road infrastructure element operating alternately between its first state and its second state according to a fixed, predetermined and predictable operating cycle, the operating cycle and the other static and / or dynamic data relating to the road infrastructure and / or road traffic being supplied as input to the computer, the vehicle being further provided with a navigation and positioning system and a power system of the vehicle, both of which being connected to the computer, the route of the vehicle within a predetermined distance being predefined or predicted in the computer, the computer being configured to calculate an optimal speed profile for the vehicle according to a predefined calculation method, the calculation method being configured to make it possible to minimize energy consumption, the method further comprising: a sub-method for optimizing the energy consumption of the vehicle as described above; and transmitting to the power system of the vehicle a speed command established according to the optimal speed profile of the vehicle taken into account.
[0030] This control method makes it possible to filter the speed of the vehicle according to an optimal speed profile of the vehicle taken into account in order to minimize the energy consumption of the vehicle. This control method can be implemented when the computer of the vehicle is connected to the speed regulator and thus to the power system, or when the computer is on board the vehicle in an autonomous or semi-autonomous manner, the speed regulator being provided with means for calculating the speed setpoint.
[0031] The invention also relates to a computer intended to be on board a vehicle, in which the route of the vehicle within a predetermined distance is predefined or predicted, the computer being configured to calculate an optimal speed profile for the vehicle according to a predefined calculation method, the calculation method being configured to make it possible to minimize the energy consumption of the vehicle, the computer comprising means for implementing the steps of one of the methods described above.
[0032] The invention also relates to a vehicle, in particular a motor vehicle, having an on-board computer as described above and a navigation and positioning system of the vehicle connected to the computer, which computer can be connected to a system for managing static and / or dynamic data related to road infrastructure and / or road traffic.
[0033] According to a specific technical feature of the present invention, the vehicle further comprises: a display device capable of displaying the speed of the vehicle; and / or a speed governor provided with a device for calculating a speed set point and connected to the power system of the vehicle, the display device and / or the speed governor being connected to a computer.
[0034] Preferably, the vehicle is an autonomous or semi-autonomous vehicle.
[0035] The present invention also relates to a computer program product, which can be downloaded from a communication network and / or recorded on a medium that is readable by a computer and / or can be executed by a processor. The computer program product includes program instructions, and when the instructions are executed on a computer as described above, the program instructions are constructed to implement the steps of one of the methods described above. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Embodiments of the invention will be described below by way of non-limiting examples and with reference to the accompanying drawings, in which:
[0037] Figure 1 A vehicle and a road traffic light are schematically illustrated, the vehicle being provided with an on-board computer;
[0038] Figure 2 It is shown that according to the present invention Figure 1 A flowchart of a computer-implemented method for controlling the speed of a vehicle, the method including a sub-method for optimizing energy consumption of the vehicle; and
[0039] Figure 3 Schematic diagram of the prediction Figure 1 The operation cycle and time range of the road traffic light status in. DETAILED DESCRIPTION
[0040] refer to Figure 2 The present invention relates to a method for controlling the speed of a vehicle 2, wherein the method comprises: Figure 1 The vehicle 2 is typically a motor vehicle, such as (but not limited to) an autonomous or semi-autonomous vehicle. The vehicle 2 moves within a road environment in which one or more road infrastructure elements 6 are arranged. Each road infrastructure element 6 (in Figure 1In a specific exemplary embodiment of the invention, the road infrastructure element 6 (for example a three-color road traffic signal) has a first open or passable state and a second closed or stopped state. When the road infrastructure element 6 is a road traffic signal, the first open or passable state corresponds to the green light emitted by the traffic signal, and the second closed or stopped state in turn corresponds to the red color. Each road infrastructure element 6 operates alternately in its first state and in its second state according to a fixed, predetermined and predictable operating cycle 7. Figure 3 Such an operating cycle 7 is illustrated by way of example in FIG. 6 , for example a road traffic light 6 . Figure 3 In the embodiment, the phase of the cycle 7 corresponding to the first open or passing state of the road traffic light 6 is denoted by the reference symbol E1, and the phase of the cycle 7 corresponding to the second closed or stopped state is denoted by the reference symbol E2. Figure 3 , the X-axis corresponds to the time axis, and shows the third state E3 of the road traffic light 6 (the third state E3 corresponds to the “yellow light” intermediate state of the road traffic light 6 ).
[0041] The computer 4 is, for example, part of a data processing unit on which an application program or computer program (for the sake of clarity, Figure 1 The data processing unit and the application or computer program are not shown in the figure). As a variant, the application or computer program is stored directly in the computer 4. The computer 4 is connected to the vehicle's power system (not shown) and to a system 8 for managing static and / or dynamic data relating to road infrastructure and / or road traffic. More specifically, the computer 4 is connected to the system 8 for managing static and / or dynamic data via a wireless communication device 10 on board the vehicle 2, for example. The wireless communication device 10 is composed, for example, of a data transmitter / receiver connected to an electronic communication card, such as a SIM (Subscriber Identity Module) card. The system 8 for managing static and / or dynamic data is, for example, constructed in a cloud architecture and makes it possible to provide (or even predict) a time range H1 regarding an operating cycle 7 (or state change cycle) of a road infrastructure element 6 detected as being in front of the vehicle during its journey, in particular depending on the speed of the vehicle and the traffic density on the road. The static and / or dynamic data managed by the management system 8 and transmitted to the computer 4 of the vehicle include in particular state data relating to the road infrastructure element 6. The time range H1 provided (or predicted) by the management system 8 can be in Figure 3, and makes it possible to obtain the state or phase of each road infrastructure element 6 detected as being in front of the vehicle within a time interval defined by the time range H1. The management system 8 is, for example, an electronic horizon information system (or e Horizon, which is conventionally based on ADASIS or the Advanced Driver Assistance System Interface Specification, a data format standard for predictive driver assistance systems, or any other type of mechanism). As known per se, such an eHorizon system makes it possible to manage both static data related to the road infrastructure (such as, for example, the nature of the roads and intersections, the legal speed limits in force, etc.) and dynamic data (average speed of vehicles located on the road, traffic density, dynamic data related to the road infrastructure elements 6, etc.). Such an eHorizon system is able to receive this data, decode it (via a decoder), reconstruct it (via a data reconstructor) and transmit it to the computer 4 and implement a path prediction algorithm for the vehicle 2 using the “most probable path” concept.
[0042] The computer 4 is configured to calculate the optimal speed profile of the vehicle 2 according to a predefined calculation method. This predefined calculation method (which is, for example, pre-recorded in a data processing unit comprising the computer 4) is configured to make it possible to minimize the energy consumption of the vehicle 2. This predefined calculation method is, for example, a calculation method that implements the Pontryagin maximum principle. As a variant, the calculation method can also be any other calculation method that implements a fixed or free final state optimization and makes it possible to minimize the energy consumption of the vehicle 2 (such as, for example, a dynamic programming method, or a Lagrangian method, or a method based on a neural network).
[0043] In addition to the computer 4 and the wireless communication device 10, the vehicle 2 also has an onboard navigation and positioning system 12 of the vehicle 2, which is connected to the computer 4. The navigation and positioning system 12 is, for example, a GPS or global positioning system. The navigation map implemented in the navigation and positioning system 12 is instrumented. Preferably, the vehicle 2 also has an onboard display device 14 (such as, for example, a screen) connected to the computer 4. More preferably, the vehicle 2 also has an onboard ADAS or advanced driver assistance system 16 connected to the computer 4, such as a radar or LIDAR. Such ADAS 16 is generally formed as a device for measuring or estimating the distance between the vehicle 2 and another vehicle immediately before the vehicle 2, and / or a device for measuring or estimating the relative speed of the other vehicle. According to a specific exemplary embodiment of the present invention, the vehicle 2 also includes a speed regulator (not shown), which is provided with a device for calculating a speed set point and is connected to both the power system of the vehicle 2 and the computer 4.
[0044] like Figure 2As shown in FIG. 2 , the method comprises a sub-method 20 for optimizing the energy consumption of the vehicle 2 , which method is implemented in a computer 4 on board the vehicle 2 .
[0045] Initially, the operating cycle 7 (at least over the time horizon H1) of each road infrastructure element 6 (or at least the next road infrastructure element 6 to come) located on the route of the vehicle, as well as other static and / or dynamic data related to the road infrastructure and / or road traffic and managed by the management system 8, is supplied as input to the computer 4 via the management system 8. In addition, the route of the vehicle 2 within a predetermined distance is predefined in the computer 4 (e.g., via user input) or predicted (e.g., via the management system 8, which transmits the information to the computer 4). The computer 4, for example, runs an application or a computer program for implementing the method.
[0046] The sub-method 20 comprises an initial step 22 during which the computer 4 determines the distance D1 between the vehicle 2 and the next road infrastructure element 6 situated on the route of the vehicle 2 .
[0047] Preferably, the sub-method 20 comprises a subsequent step 23 during which the computer 4 detects at least one other vehicle moving in the same direction as the vehicle 2 and being located between the vehicle 2 and the next road infrastructure element 6 on the route of the vehicle 2. This detection step 23 is implemented, for example, via data transmitted to the computer 4 by radar or ADAS 16. According to a particular exemplary embodiment, the relative speed of the other vehicle is estimated, for example, by the computer 4 according to the operating cycle 7 of the next road infrastructure element 6 and a model of the vehicle reaction when the road infrastructure element switches from its closed or stopped state to its open or passable state and vice versa (e.g. pre-recorded, or based on prediction equations). If the computer 4 detects at least one such other vehicle, the sub-method 20 comprises a subsequent step 24 during which the computer 4 determines the distance between the vehicle 2 and the vehicle immediately preceding it on the route of the vehicle 2 and then replaces the distance D1 determined during the initial step 22 with this distance.
[0048] The sub-method 20 comprises a subsequent step 26 during which, in a first calculation mode of the calculation method, the computer 4 calculates an optimal speed profile for the vehicle 2 as a function of the distance D1 determined during the initial step 22 or the distance determined during the step 24. In this first calculation mode, the speed of the vehicle 2 at the moment of its arrival at the next road infrastructure element 6 and the time for the vehicle 2 to arrive at this next road infrastructure element 6 are unconstrained (optionally, if another vehicle ahead of the vehicle 2 has been detected during step 23, the relative speed of this vehicle is taken into account - in this case, the optimal speed profile calculation is adapted to synchronize the speed at the moment of catching up with this moving vehicle ahead). In this first calculation mode of the calculation method, the assumption is made that the next road infrastructure element 6 will be in its first open or passable state at the moment of the vehicle 2 arriving at said road infrastructure element 6.
[0049] Sub-method 20 comprises a subsequent step 28 during which computer 4 calculates the time of arrival of vehicle 2 for the next road infrastructure element 6 or for the next vehicle ahead of vehicle 2 (if such a vehicle has been detected during step 23 ) according to the optimal speed profile calculated during step 26 .
[0050] The sub-method 20 comprises a subsequent step 30 during which the computer 4 determines the state of the road infrastructure element 6 at the moment of arrival of the vehicle 2 at the road infrastructure element 6 as a function of the time calculated during step 28 and the operating cycle 7 of the next road infrastructure element 6 .
[0051] The sub-method 20 comprises a subsequent step 32 during which the computer 4 compares the state of the next road infrastructure element 6 determined during step 30 with the first open or trafficable state of said road infrastructure element 6 .
[0052] If the state of the next road infrastructure element 6 determined during step 30 corresponds to the first open or trafficable state, the sub-method 20 comprises a subsequent step 34 during which the computer 4 takes into account the optimal speed profile for the vehicle 2 calculated during step 26 in order to apply or recommend it to the vehicle 2. The sub-method 20 then ends.
[0053] If the state of the next road infrastructure element 6 determined during step 30 does not correspond to the first open or passable state (and therefore to the second closed or stopped state), the sub-method 20 comprises a subsequent step 36 during which, in a second calculation mode of the calculation method, the computer 4 calculates the optimal speed profile for the vehicle 2 as a function of the distance D1 determined during the initial step 22 or the distance determined during step 24. In this second calculation mode, the speed of the vehicle 2 at the moment of arrival at the next road infrastructure element 6 is fixed at a zero value and supplied as an input to the calculation method. The time of arrival of the vehicle 2 at the next road infrastructure element 6 is not constrained (optionally, if another vehicle ahead of the vehicle 2 has been detected during step 23, the relative speed of this vehicle is taken into account - in this case, the optimal speed profile calculation is adapted to synchronize the speed at the moment of catching up with this moving vehicle ahead). In this second calculation mode of the calculation method, the assumption is made that the next road infrastructure element 6 will be in its second closed or stopped state at the moment of arrival of the vehicle 2 at said road infrastructure element 6.
[0054] Sub-method 20 comprises a subsequent step 38 during which computer 4 calculates the time of arrival of vehicle 2 for the next road infrastructure element 6 or for the next vehicle ahead of vehicle 2 (if such a vehicle has been detected during step 23 ) according to the optimal speed profile calculated during step 36 .
[0055] The sub-method 20 comprises a subsequent step 40 during which the computer 4 determines the state of the road infrastructure element 6 at the moment of arrival of the vehicle 2 at the road infrastructure element 6 as a function of the time calculated during step 38 and the operating cycle 7 of the next road infrastructure element 6 .
[0056] The sub-method 20 comprises a subsequent step 42 during which the computer 4 compares the state of the next road infrastructure element 6 determined during step 40 with a second closed or stopped state of said road infrastructure element 6 .
[0057] If the state of the next road infrastructure element 6 determined during step 40 corresponds to a second closed or stopped state, the sub-method 20 comprises a subsequent step 44 during which the computer 4 takes into account the optimal speed profile for the vehicle 2 calculated during step 36 in order to apply or recommend it to the vehicle 2. The sub-method 20 then ends.
[0058] If the state of the next road infrastructure element 6 determined during step 40 does not correspond to the second closed or stopped state (and therefore to the first open or passable state), the sub-method 20 comprises a subsequent step 46 during which, in a third calculation mode of the calculation method, the computer 4 calculates the optimal speed profile for the vehicle 2 as a function of the distance D1 determined during the initial step 22 or the distance determined during step 24. In this third calculation mode, the speed of the vehicle 2 at the moment of reaching the next road infrastructure element 6 is unconstrained (optionally, if another vehicle ahead of the vehicle 2 has been detected during step 23, the relative speed of this vehicle is taken into account - in this case, the optimal speed profile calculation is adapted to synchronize the speed at the moment of catching up with this moving vehicle ahead). The time of arrival of the vehicle 2 at the next road infrastructure element 6 is fixed to the time at which said road infrastructure element 6 switches to the next first open or passable state reachable by the vehicle 2 and is supplied as an input to the calculation method. In this third calculation mode of the calculation method, the assumption is made that the next road infrastructure element 6 will have just switched to its first open or passable state at the moment of arrival of the vehicle 2 at said road infrastructure element 6.
[0059] The sub-method 20 comprises a subsequent step 48 during which the computer 4 takes into account the optimal speed profile for the vehicle 2 calculated during step 46 in order to apply or recommend this optimal speed profile to the vehicle 2. The sub-method 20 then ends.
[0060] Preferably, the sub-method 20 further comprises a step 50 implemented after step 46 when none of the steps 26, 36 and 46 of calculating the optimal speed profile of the vehicle 2 gives an acceptable solution for the vehicle 2, during which, in a fourth calculation mode of the calculation method, the computer 4 calculates the optimal speed profile of the vehicle 2 according to the distance D1 determined during the initial step 22 or the distance determined during step 24. An "acceptable solution for the vehicle" is intended to mean any mathematical solution that complies with the physical and legal constraints relating to the vehicle 2, the road infrastructure or the road network (such as, for example, speed limits on the network). In this fourth calculation mode of the calculation method, the speed of the vehicle 2 at the moment of reaching the next road infrastructure element 6 is fixed at a zero value and the time of the vehicle 2 reaching the next road infrastructure element 6 is fixed to the time at which said road infrastructure element 6 switches to the next second closed or stopped state. The speed of the vehicle 2 at the moment of reaching the next road infrastructure element 6 and the time at which the vehicle 2 reaches the next road infrastructure element 6 are supplied as inputs to the calculation method. In this fourth calculation mode of the calculation method, the assumption is made that the next road infrastructure element 6 will have just switched to its second closed or stopped state at the moment at which the vehicle 2 reaches said road infrastructure element 6. The sub-method 20 comprises a subsequent step 52 during which the computer 4 takes into account the optimal speed profile for the vehicle 2 calculated during step 50 in order to apply or recommend this optimal speed profile to the vehicle 2 . The sub-method 20 then ends.
[0061] More preferably, the sub-method 20 further comprises a phase of detecting, by the computer 4, at least one predetermined condition or at least one predetermined event (such a detection phase is in Figure 2 23 and step 52). If the computer 4 detects at least one such predetermined condition or one such predetermined event, the sub-method 20 loops back to the initial step 22 as follows: the distance between the vehicle 2 and the next road infrastructure element 6 located on the route of the vehicle 2 is determined taking into account the new current position of the vehicle 2. Such a predetermined event is, for example, an event such as a break in the route of the vehicle. Such a predetermined condition is, for example, a difference between the actual speed of the vehicle 2 and a prediction made by the computer 4, or a difference between the actual state of the next road infrastructure element 6 and a prediction made by the computer 4.
[0062] The method for controlling the speed of the vehicle 2 comprises a final step 54 during which the computer 4 transmits to the power system of the vehicle 2 a speed command established according to the optimal speed curve of the vehicle taken into account during one of the steps 34, 44, 48 or 52. When the vehicle 2 comprises a governor, the computer 4 transmits the speed command to the governor, and the governor then calculates a speed set point established according to the speed command. The speed of the vehicle 2 is then regulated according to the speed set point (which can vary according to the calculated speed command). As a variant, the vehicle 2 can also be an autonomous or semi-autonomous vehicle, in which case the computer 4 can directly transmit the speed command to the power system of the vehicle 2. As a further variant, the method 20 for optimizing the energy consumption of the vehicle 2 according to the invention can be used to recommend to the driver the optimal speed curve of the vehicle 2 taken into account by the computer 4 (in which case the final step 54 is absent). This recommendation is made, for example, by displaying information on the display device 14, such information, for example, in the form of a colored (dynamic) graphic recommendation area, in which the driver is encouraged to place a pointer representing the speed of the vehicle 2 (the position of the pointer is controlled by the accelerator pedal).
[0063] Once the vehicle has passed a road infrastructure element 6 , the method for controlling the speed of the vehicle 2 loops back to the sub-method 20 for the next road infrastructure element located on the route of the vehicle 2 .
[0064] The method for optimizing the energy consumption of a vehicle 2 according to the invention makes it possible for the vehicle 2 to calculate the optimal speed profile to be followed in order to reach the next road infrastructure element 6, while covering the distance from the current position of the vehicle 2 to this element 6 and providing an optimal time synchronization with the phase or state of said road infrastructure element 6. This method thus makes it possible to minimize the energy consumption of the vehicle in an optimal way and provides a reduction of its energy consumption of approximately 10% to 20% depending on the driving situation. In addition, the method according to the invention is applicable to all types of vehicles (two-, three- or four-wheeled vehicles, commercial vehicles, buses, trucks, etc.).
Claims
1. A method (20) for optimizing the energy consumption of a vehicle (2), the method being implemented in a computer (4) on board the vehicle (2), the computer (4) of the vehicle (2) being connected to a system (8) for managing static and / or dynamic data relating to road infrastructure and / or road traffic, the static and / or dynamic data comprising status data relating to at least one road infrastructure element (6) having a first open or passable state (E1) and a second closed or stopped state (E2), the road infrastructure element (6) being in its first state (E1) and in its second state (E2) according to a fixed, predetermined and predictable operating cycle (7). The operation cycle (7) and the other static and / or dynamic data related to the road infrastructure and / or road traffic are supplied as inputs to the computer (4), the vehicle (2) is further provided with a navigation and positioning system (12) of the vehicle (2) connected to the computer (4), the route of the vehicle (2) within a predetermined distance is predefined or predicted in the computer (4), the computer (4) is configured to calculate the optimal speed curve of the vehicle (2) according to a predefined calculation method, the calculation method is configured to make it possible to minimize the energy consumption of the vehicle (2), and the method (20) comprises the following steps: - determining (22) a distance (D1) between the vehicle (2) and a next road infrastructure element (6) located on the route of the vehicle (2); - calculating (26) an optimal speed profile for the vehicle (2) according to the determined distance (D1) in a first calculation mode of the calculation method, wherein the speed of the vehicle at the moment of arrival at the road infrastructure element (6) and the time at which the vehicle (2) arrives at the road infrastructure element (6) are unconstrained, the state of the road infrastructure element (6) being assumed to be the first open or passable state (E1) at the moment of arrival of the vehicle (2) at the road infrastructure element (6); - calculating (28) the time at which the vehicle (2) will arrive at the road infrastructure element (6) according to the calculated optimal speed profile; - determining (30) the state of the road infrastructure element (6) at the moment when the vehicle (2) reaches the road infrastructure element (6) based on the calculated time and the operating cycle (7) of the road infrastructure element (6); - comparing (32) the determined state with a first open or trafficable state (E1) of the road infrastructure element (6); - if the determined state of the road infrastructure element (6) corresponds to the first open or passable state (E1), the computer (4) takes into account (34) the optimal speed profile for the vehicle (2) calculated according to the first calculation mode in order to apply or recommend the optimal speed profile to the vehicle (2); If the determined state of the road infrastructure element (6) does not correspond to the first open or trafficable state (E1): o calculating (36) an optimal speed profile for the vehicle (2) according to the determined distance (D1) in a second calculation mode of the calculation method, in which the speed of the vehicle (2) at the moment of arrival at the road infrastructure element (6) is fixed at zero and supplied as an input to the calculation method, and the time of arrival of the vehicle (2) at the road infrastructure element (6) is unconstrained, and the state of the road infrastructure element (6) at the moment of arrival of the vehicle (2) at the road infrastructure element (6) is assumed to be the second closed or stopped state (E2); o calculating (38) a time for the vehicle (2) to arrive at the road infrastructure element (6) based on the calculated optimal speed profile; o determining (40) the state of the road infrastructure element (6) at the moment when the vehicle arrives at the road infrastructure element (6) based on the calculated time and the operating cycle (7) of the road infrastructure element (6); o comparing (42) the determined state with the second closed or stopped state (E2) of the road infrastructure element (6); o if the determined state of the road infrastructure element (6) corresponds to the second closed or stopped state (E2), the computer (4) takes into account (44) the optimal speed profile of the vehicle (2) calculated according to the second calculation mode in order to apply or recommend the optimal speed profile to the vehicle (2); o If the determined state of the road infrastructure element (6) does not correspond to the second closed or stopped state (E2): ■ calculating (46) an optimal speed profile for the vehicle (2) based on the determined distance (D1) in a third calculation mode of the calculation method, in which the speed of the vehicle (2) at the moment of arrival at the road infrastructure element (6) is unconstrained and the time at which the vehicle (2) arrives at the road infrastructure element (6) is fixed to the time at which the road infrastructure element (6) switches to the next first open or passable state that the vehicle (2) can reach, the time being supplied as an input to the calculation method, the road infrastructure element (6) being assumed to have just switched to its first open or passable state (E1) at the moment at which the vehicle (2) arrives at the road infrastructure element (6); ■ The computer (4) takes into account (48) the optimal speed profile of the vehicle (2) calculated according to the third calculation mode in order to apply or recommend the optimal speed profile to the vehicle (2).
2. The method (20) according to claim 1, characterized in that: The method (20) further comprises the following: a step (50) of calculating the optimal speed curve of the vehicle (2) according to the determined distance (D1) in a fourth calculation mode of the calculation method, implemented when none of the steps (26, 36, 46) of calculating the optimal speed curve of the vehicle (2) gives an acceptable solution for the vehicle (2), in which the speed of the vehicle (2) at the moment of reaching the road infrastructure element (6) is fixed at zero and the time of arrival of the vehicle (2) at the road infrastructure element (6) is fixed to the time at which the road infrastructure element (6) switches to the next second closed or stopped state (E2), the speed of the vehicle (2) and the time being supplied as inputs to the calculation method, the road infrastructure element (6) being assumed to have just switched to its second closed or stopped state (E2) at the moment of arrival of the vehicle (2) at the road infrastructure element (6); and a step (52) of the computer (4) taking into account the calculated optimal speed curve of the vehicle in order to apply or recommend the optimal speed curve to the vehicle (2).
3. The method (20) according to claim 1 or 2, characterized in that: The vehicle (2) further has an on-board device (16) for measuring or estimating the distance between the vehicle (2) and another vehicle immediately preceding the vehicle (2) and / or a device (16) for measuring or estimating the relative speed of the other vehicle, the measuring or estimating device (16) being connected to the computer (4), and the method (20) further comprises the following: a step (23) of detecting at least one other vehicle on the route of the vehicle (2), the at least one other vehicle moving in the same direction as the vehicle (2) and being located between the vehicle (2) and the next road infrastructure element (6); and a step (24) carried out in the event of the detection of at least one such other vehicle, the step consisting in determining the distance between the vehicle (2) and the such other vehicle immediately preceding it on the route of the vehicle (2), and then replacing the determined distance (D1) between the vehicle (2) and the next road infrastructure element (6) by the distance between the vehicle (2) and the such other vehicle immediately preceding it on the route of the vehicle (2) before the first calculation step (26).
4. The method (20) according to any one of claims 1 to 3, characterized in that The method (20) further comprises a phase of detecting at least one predetermined condition or at least one predetermined event, and in that, if at least one such predetermined condition or one such predetermined event is detected, the method (20) loops back to the following step (22): determining the distance (D1) between the vehicle (2) and the next road infrastructure element (6) located on the route of the vehicle (2) taking into account the new current position of the vehicle (2).
5. The method (20) according to any one of claims 1 to 4, characterized in that The predefined calculation method is a calculation method that implements the Pontryagin maximum principle.
6. A method for controlling the speed of a vehicle (2), the method being implemented in a computer (4) on board the vehicle (2), the computer (4) of the vehicle (2) being connected to a system (8) for managing static and / or dynamic data relating to road infrastructure and / or road traffic, the static and / or dynamic data comprising status data relating to at least one road infrastructure element (6) having a first open or passable state (E1) and a second closed or stopped state (E2), the road infrastructure element (6) operating alternately in its first state (E1) and its second state (E2) according to a fixed, predetermined and predictable operating cycle (7), the operating cycle The loop (7) and the other static and / or dynamic data related to the road infrastructure and / or road traffic are supplied as input to the computer (4), the vehicle (2) is further provided with a navigation and positioning system (12) and a power system of the vehicle, both of which are connected to the computer (4), the route of the vehicle (2) within a predetermined distance is predefined or predicted in the computer (4), the computer (4) is configured to calculate the optimal speed curve of the vehicle (2) according to a predefined calculation method, the calculation method being configured to make it possible to minimize the energy consumption of the vehicle (2), characterized in that The method further comprises: a sub-method (20) for optimizing the energy consumption of the vehicle (2) according to any one of claims 1 to 5; and a step (54) of transmitting to the power system of the vehicle (2) a speed command established according to the optimal speed curve of the vehicle (2) taken into account.
7. A computer (4) intended to be placed on board a vehicle (2), the route of the vehicle (2) within a predetermined distance being predefined or predicted in the computer (4), the computer (4) being configured to calculate an optimal speed profile for the vehicle (2) according to a predefined method, the calculation method being configured to make it possible to minimize the energy consumption of the vehicle (2), characterized in that The computer (4) comprises means for implementing the steps of the method according to any one of claims 1 to 6.
8. A vehicle (2), in particular a motor vehicle, characterized in that The vehicle (2) has an on-board computer (4) according to claim 7 and a navigation and positioning system (12) of the vehicle (2) connected to the computer (4), the computer (4) being connectable to a system (8) for managing static and / or dynamic data relating to road infrastructure and / or road traffic.
9. The vehicle (2) according to claim 8, characterized in that The vehicle (2) further comprises: a display device (14) capable of displaying the speed of the vehicle (2); and / or a speed regulator provided with means for calculating a speed set point and connected to the power system of the vehicle (2), the display device (14) and / or the speed regulator being connected to the computer (4).
10. The vehicle (2) according to claim 8 or 9, characterized in that The vehicle (2) is an autonomous or semi-autonomous vehicle.
11. A computer program product, which can be downloaded from a communication network and / or recorded on a medium readable by a computer and / or executable by a processor, characterized in that: The computer program product comprises program instructions which are configured to implement the steps of the method according to any one of claims 1 to 6 when the instructions are run on a computer (4) according to claim 7.