STARTING CONTROL SYSTEM FOR AN INTERNAL COMBUSTION ENGINE OF A MOTOR VEHICLE, METHOD AND VEHICLE BASED ON SUCH A SYSTEM
A control system for hybrid vehicles monitors clutch and parking locking mechanisms to prevent unexpected clutch openings, ensuring reliable engine start-up by authorizing or prohibiting starts based on estimated conditions.
Patent Information
- Application Number
- FR2022000238
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-01-13
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2042-01-13
AI Technical Summary
The existing hybrid vehicle systems face issues with the KO clutch opening unexpectedly during engine start-up or restart due to shared hydraulic circuits with the parking locking system, leading to unreliable start-up sequences, as the clutch information is not sensed accurately.
A control system with a cruise box calculator and a control calculator that estimates clutch coupling conditions and parking locking mechanism states to authorize or prohibit engine starts, using torque thresholds and temperature maps to ensure reliable engine start-up.
The system prevents unexpected clutch openings during start-up by continuously monitoring clutch and parking locking mechanism states, ensuring successful engine starts and reducing failure risks.
Smart Images
Figure 00000010_0000
Abstract
Description
Title of the invention: SYSTEM FOR CONTROLLING THE STARTING OF A HEAT ENGINE OF A MOTOR VEHICLE, METHOD AND VEHICLE BASED ON SUCH A SYSTEM
[0001] The invention relates to the field of hybrid vehicles equipped with an electrified transmission system, comprising a coupling system with the internal combustion engine and a parking lock system with a common hydraulic circuit. More particularly, the invention relates to a system and method for controlling the starting of the internal combustion engine of such a motor vehicle.
[0002] In these hybrid vehicles, the starts / restarts of the internal combustion engine MT via the electrified transmission system eD are constrained by a state of the KO coupling system located between the internal combustion engine MT and the gearbox BV, in an architecture that can be illustrated by [Fig. 1]. Thus, during a start / restart phase, if the selected component is the electrified transmission system, it is necessary to ensure that the KO coupling is locked closed so that the electric machine EM of the electrified transmission system, or the torque from the wheel R, can be transmitted to the internal combustion engine MT.
[0003] The current problem lies in defining the organic architecture of the electrified transmission system eD, generally called "e-Transmission" or "eDCT". The design of this system is such that: - The hydraulic circuit of the clutch KO is shared with that of the parking lock system (generally called "park lock" or park finger) allowing the mechanical locking of the gearbox. - The information about the torque transmitted by the KO clutch, used to construct the state of the coupling, is an estimated information not derived from a sensor.
[0004] In fact, during a start / restart phase, if the user requests the engagement or disengagement of the parking lock, there is a risk that the KO clutch will open due to a sudden drop in hydraulic pressure linked to the physical engagement / disengagement of the parking lock, resulting in the failure of the start / restart sequence.
[0005] The invention aims to overcome the problems of the prior art.
[0006] Thus, the invention proposes a system for controlling the start of a thermal engine of a hybrid type motor vehicle comprising an electrified transmission system including a clutch connected to a mechanism of parking lock via a common hydraulic circuit, the starting control system including - a gearbox control unit configured to estimate the clutch coupling state, and to estimate the engagement state of the parking lock mechanism, and - a control computer controlling the stopping and restarting of the internal combustion engine and an electronic gear lever of the vehicle, the control computer being configured to allow or prohibit a starting of the internal combustion engine, depending on said clutch coupling state, and said state of the parking lock mechanism, as well as the starting or stopping state of the internal combustion engine.
[0007] Advantageously, the powertrain supervision by the control computer will continuously analyze the consistency of the state of the position of the gear lever of the electrified transmission system, as well as the state of the parking lock mechanism in order to judge the ability of the system to successfully start / restart and thus avoid failures.
[0008] According to a variant, the gearbox computer is configured to estimate the coupling state of the clutch by comparing an estimated transmitted torque of said clutch respectively to a low transmitted torque threshold, and to a high transmitted torque threshold, to conclude in an open state if the transmitted torque is lower than said low threshold, or closed said torque is higher than said high threshold.
[0009] According to a variant, the gearbox computer is configured to determine the low threshold of transmitted torque corresponding to the open state, and the high threshold of transmitted torque corresponding to the closed state, from two maps which depend on an estimated temperature of said clutch or a gearbox oil temperature.
[0010] According to a variant, the control computer is configured, when the gear lever is in the parking position, to - prohibit any start / restart request if the parking lock mechanism is not seen engaged and the internal combustion engine has not yet started / restarted; or - interrupt a start / restart request if the parking lock mechanism is not seen engaged and the internal combustion engine is in the process of starting / restarting.
[0011] Advantageously, this makes it possible to implement, in this context, a use case called a preventive “non-capacity system” in the first hypothesis or a use case called a curative “non-capacity system” in the second hypothesis.
[0012] According to one variant, the control unit is configured, when the gear lever is in the park position, to - allow the internal combustion engine to start / restart if the parking lock mechanism is seen to be engaged and the internal combustion engine has not yet started / restarted; or - allow all start / restart requests if the parking lock mechanism is not seen engaged and if the gear lever has been in the parking position for a calibrable initial time and the internal combustion engine has not yet been started / restarted.
[0013] Advantageously, this allows the implementation, in this context, of a use case called a "capacity system" in the first hypothesis or a use case called a "reinforcement (back up) capacity system" in the second hypothesis.
[0014] According to a variant, the control computer is configured, when the gear lever is not in the parking position, to - prohibit any start / restart request if the parking lock mechanism is not seen disengaged and the internal combustion engine has not yet been started / restarted; or - interrupt the start / restart request if the parking lock mechanism is not seen disengaged and the thermal engine is starting / restarting.
[0015] Advantageously, this allows the implementation, in this context, of a use case called a preventive “non-capacity system” in the first hypothesis or a use case called a curative “non-capacity system” in the second hypothesis.
[0016] According to a variant, the control computer is configured, when the gear lever is not in the parking position, to - authorize the starting / restarting of the thermal engine if the parking lock mechanism is seen to be disengaged and the thermal engine has not yet been started / restarted; - allow all start / restart requests if the parking lock mechanism is not seen to be disengaged and if the gear lever has left the parking position for a second calibratable time and the combustion engine has not yet started / restarted.
[0017] Advantageously, this makes it possible to implement, in this context, a use case called a “capacity system” in the first hypothesis or a use case called a “capacity system” of reinforcement (back up) in the second hypothesis.
[0018] The invention further relates to a method for controlling the start of a thermal engine of a hybrid type motor vehicle comprising an electronic transmission system including a clutch connected to a mechanism of parking lock by a common hydraulic circuit, the start control method comprising - an estimation step for estimating the clutch coupling state, and for estimating the engagement state of the parking lock mechanism, and - a control step for authorizing or prohibiting a start of the thermal engine, depending on said clutch coupling state, and said state of the parking lock mechanism, taking into account the start or stop state of the thermal engine.
[0019] Another object of the invention relates to a computer program comprising program code instructions for executing the steps of the control method according to the invention, when said program operates on a computer.
[0020] The invention further relates to a hybrid type motor vehicle comprising a control system according to the invention.
[0021] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, including:
[0022] [Fig-1] [Fig.l] illustrates a diagram of the control system according to the invention in a motor vehicle engine architecture; and
[0023] [Fig.2] [Fig.2] schematically illustrates the functionalities of the control system according to the invention.
[0024] The invention relates to a system for controlling the start of the thermal engine MT of a hybrid type motor vehicle, more particularly of the type equipped with an electrified transmission system eD comprising a coupling system KO with the thermal engine MT and a parking locking system VS whose hydraulic circuit is common. In particular, it is a parking finger VS.
[0025] This type of electrified transmission system is generally called "e-Transmission" or "eDCT". The design of this system is such that: - The hydraulic circuit of the clutch KO is shared with that of the parking lock system VS allowing the mechanical locking of the gearbox BV. - The torque information transmitted by the KO clutch, used to construct the coupling status, is estimated information not derived from a sensor.
[0026] During a start / restart phase, if the user requests the engagement or disengagement of the parking lock mechanism, there is a risk that the KO clutch will open due to a sudden drop in hydraulic pressure linked to the physical engagement / disengagement of the parking lock, resulting in the start / restart sequence failing.
[0027] The invention proposes a start-up control system that can be illustrated by [Fig.2], to limit this risk. It can be implemented in the form of a CMM control computer associated with a TCU gearbox computer. In particular, the GMP (Global Modular Platform) supervision is hosted in the CMM control computer, which is responsible for managing the restart sequence of the MT thermal engine. The calculations and commands are therefore implemented via a network of computers.
[0028] The gear lever is electronic, i.e., without a mechanical link to the gearbox. Furthermore, its functional architecture is housed within a CMM control unit.
[0029] The lever commands are sent from the CMM control computer to a TCU gearbox computer which must react as a slave. The TCU gearbox computer physically controls the engagement / disengagement of the VS parking finger allowing the parking to be locked / unlocked. It then provides feedback to the CMM control computer on its physical state (action / reaction).
[0030] Concerning the clutches KO, K1 and K2, the TCU computer is responsible for estimating the torque transmitted by the latter (based on a model taking into account several physical criteria), and it then sends this information to the CMM control computer which will use this data to construct the coupling state of each of the clutches based on configurable transmitted torque thresholds (in the form of hysteresis to detect the open and closed states).
[0031] The CMM control unit controls the stop / restart (so-called "Stop and Start" function); calculates the state of the clutches; checks the consistency of the position of the gear lever and the position of the VS parking finger.
[0032] The gearbox calculator TCU sends to the control calculator CMM the estimated transmitted torque of the clutch KO, and the position of the parking finger VS.
[0033] According to the invention, the CMM control computer is configured to allow or prohibit a start of the MT thermal engine, depending on parameters of the estimation means and the start or stop state of the MT thermal engine.
[0034] A control box CB can house the control computer CMM and the gearbox computer TCU. Advantageously, the supervision of a powertrain by the control computer CMM will continuously analyze the consistency of the state of the position of the gear lever of the electrified transmission system eD as well as that of the parking lock mechanism VS in order to judge the capacity of the system to successfully start / restart and thus avoid failures.
[0035] We distinguish 2 life situations: - Shifting the gear lever into the park position; and - Shifting the gear lever out of the park position.
[0036] When the gear lever is in the parking position, in a use case known as a preventive “non-capacity system”: if the parking locking mechanism VS is not seen to be engaged and the thermal engine MT has not yet been started / restarted, the control computer CMM will prohibit any start / restart request.
[0037] In a use case known as a curative “non-capacity system”: if the parking locking mechanism VS is not seen to be engaged and the thermal engine MT is in the process of starting / restarting, the control computer CMM will interrupt the start / restart request.
[0038] In a use case known as a “capacity system”: if the parking VS lock is seen to be engaged and the MT thermal engine has not yet been started / restarted, then the CMM control computer will authorize the starting / restarting of the MT thermal engine.
[0039] In a use case known as a "capacity backup system": if the parking lock mechanism VS is not seen engaged and if the gear lever has been in the parking position for an initial calibrable time (called "EGD_PARK_TIME") and the internal combustion engine MT has not yet been started / restarted, the CMM control computer will allow all start / restart requests.
[0040] Conversely, when the gear lever is no longer in the parking position, in a use case known as a preventive "non-capacitive system": if the parking lock mechanism VS is not seen disengaged and the internal combustion engine MT has not yet been started / restarted, the control computer CMM will prohibit any request to start / restart.
[0041] In a use case known as a curative “non-capacity system”: if the parking locking mechanism VS is not seen to be disengaged and the thermal engine MT is in the process of starting / restarting, the control computer CMM will interrupt the start / restart request.
[0042] In a use case known as a “capacity system”: if the parking locking mechanism is seen to be disengaged and the MT thermal engine has not yet been started / restarted, then the CMM control computer authorizes the starting / restarting of the MT thermal engine.
[0043] In a use case called a “capacity backup system”: if the parking locking mechanism VS is not seen to be disengaged and if the gear lever has left the parking position for a second calibratable time called “DISEGD_PARK_TIME” and the thermal engine MT has not yet been started / restarted, the control computer CMM will authorize all start / restart requests.
[0044] The invention further relates to a computer program comprising program code instructions for executing the steps of a control method as described above, when said program runs on a computer. The program can be loaded into the memory of a control computer CMM coupled to an automatic gearbox computer TCU of the electrified transmission system eD.
[0045] Another object of the invention relates to a hybrid type motor vehicle comprising a control system as described previously.
Claims
Claims
1. System for controlling the start of a thermal engine (MT) of a hybrid type motor vehicle comprising an electrified transmission system (eD) including a clutch (KO, Kl, K2) connected to a parking lock mechanism (VS) by a common hydraulic circuit, the start control system comprising - a gearbox computer (TCU) configured to estimate the clutch coupling state (KO, Kl, K2), and to estimate the engagement state of the parking lock mechanism (VS), and - a control computer (CMM) controlling the stops and restarts of the thermal engine (MT) and an electronic gear lever of the vehicle, the control computer (CMM) being configured to authorize or prohibit a start of the thermal engine (MT), depending on said clutch coupling state (KO, Kl, K2), and said state of the parking lock mechanism (VS),as well as the starting or stopping state of the thermal engine (MT), in which the gearbox computer (TCU) is configured to estimate the coupling state of the clutch (KO, Kl, K2) by comparing an estimated transmitted torque of said clutch (KO, Kl, K2) respectively to a low transmitted torque threshold, and to a high transmitted torque threshold, to conclude in an open state if the transmitted torque is lower than said low threshold, or closed said torque is higher than said high threshold, the low transmitted torque threshold corresponding to the open state, and the high transmitted torque threshold corresponding to the closed state, being determined from two maps which depend on an estimated temperature of said clutch (KO, Kl, K2) or a gearbox oil temperature.,
2. Control system according to claim 1, characterized in that the control computer (CMM) is configured, when the gear lever is in the parking position, to - prohibit any start / restart request if the parking lock mechanism (VS) is not seen to be engaged and the thermal engine (MT) is not yet started / restarted; or - interrupt a start / restart request if the parking lock mechanism (VS) is not seen engaged and the thermal engine (MT) is starting / restarting.
3. System according to any one of claims 1 to 2, characterized in that the control computer (CMM) is configured, when the gear lever is in the parking position, to - authorize a start / restart of the thermal engine (MT) if the parking lock mechanism (VS) is seen to be engaged and the thermal engine (MT) has not yet been started / restarted; or - authorize all start / restart requests if the parking lock mechanism (VS) is not seen to be engaged and if the gear lever has been in the parking position for a first calibratable time and the thermal engine (MT) has not yet been started / restarted.
4. System according to any one of claims 1 to 3, characterized in that the control computer (CMM) is configured, when the gear lever is not in the parking position, to - prohibit any start / restart request if the parking lock mechanism (VS) is not seen to be disengaged and the thermal engine (MT) is not yet started / restarted; - interrupt the start / restart request if the parking lock mechanism (VS) is not seen to be disengaged and the thermal engine (MT) is in the process of being started / restarted.
5. System according to any one of claims 1 to 4, characterized in that the control computer (CMM) is configured, when the gear lever is not in the parking position, to - authorize the starting / restarting of the thermal engine (MT) if the parking locking mechanism (VS) is seen to be disengaged and the thermal engine (MT) has not yet been started / restarted; - authorize all start / restart requests if the parking locking mechanism (VS) is not seen to be disengaged and if the gear lever has left the parking position for a second calibratable time and the thermal engine (MT) has not yet been started / restarted.
6. A hybrid type motor vehicle comprising a control system according to any one of claims 1 to 5.