Hybrid vehicle start control system and method

Abstract

The application provides a hybrid vehicle starting control system, which comprises a main relay, two contacts of the main relay are connected with a starter and a power supply respectively, a coil of the main relay is connected with contacts of two series relay groups, and a controller is used for controlling on-off of a first relay and a second relay in the two series relay groups. The two series relay groups comprise the first relay and the second relay, the controller comprises a first controller and a second controller, the first controller controls on-off of the first relay based on an obtained engine starting condition signal, and the second controller controls on-off of the second relay based on an obtained engine second running signal. The application controls in cooperation with the main relay and the two series relay groups, automatically cuts off the power supply of the starter after the engine starts, prevents the starter from being burned due to long-time power supply and overheating, and improves the safety and reliability of the engine starting system of the hybrid vehicle.

Description

[0001] This invention is a priority claim against the invention patent application with application number 202610934860.5, filed on June 26, 2026. Technical Field

[0002] This invention relates to the field of vehicle control technology, specifically to a hybrid vehicle starting control system and method. Background Technology

[0003] Hybrid electric vehicles integrate two power systems—an engine and a drive motor—balancing fuel economy and range, and have become an important technological route in the new energy vehicle field. Under this architecture, the engine's start-stop control frequency is much higher than in traditional gasoline vehicles, placing more stringent demands on the safety and reliability of the low-pressure start control system. Currently, the engine start control strategy in hybrid vehicles typically relies on software logic judgment, supplemented by a one-way clutch built into the starter motor for passive protection. However, existing technologies have revealed numerous safety hazards in practical applications. When the engine successfully ignites and reaches a certain speed, if the starter motor drive gear fails to disengage from the flywheel in time due to mechanical jamming or control delay, the high-speed rotating engine flywheel will drag the starter motor in the opposite direction, causing the starter motor speed to momentarily exceed its design limit, resulting in armature shaft damage or complete engine failure.

[0004] Therefore, there is an urgent need for a hybrid vehicle starting control system and method to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a hybrid vehicle starting control system and method to solve the technical problems mentioned in the background art.

[0006] The first aspect of this invention provides a hybrid vehicle starting control system, including a main relay, wherein two contacts of the main relay are respectively connected to a starter motor and a power supply; The main relay coil is connected to the contacts of two relay groups connected in series. The controller is used to control the on / off state of the first and second relays in two relay groups connected in series.

[0007] Furthermore, the controller includes a first controller and a second controller; The first controller controls the on / off state of the first relay based on the acquired engine start condition signal; The second controller controls the on / off state of the second relay based on the acquired second engine operating signal.

[0008] Furthermore, the first relay is configured as a normally open contact relay; The second relay is configured as a normally closed contact relay.

[0009] Furthermore, the main relay is configured as a normally open contact relay.

[0010] Furthermore, the two relay groups connected in series include a first relay and a second relay; The first relay contact of the first relay is connected in series with the second relay contact of the second relay.

[0011] Furthermore, the input terminal of the second relay coil is connected to the coil interface terminal of the second controller, and the input terminal of the first relay coil is connected to the coil interface terminal of the first controller.

[0012] Furthermore, the first controller and the second controller interact via CAN.

[0013] A second aspect of this invention provides a hybrid vehicle start-up control method, comprising: Upon power-up, the first and second controllers are activated, the second relay closes, and the first relay opens. The first controller receives the engine starting condition signal, determines that the starting condition is met, drives the first relay to close, the main relay to close under control, and the starter motor starts. The second controller acquires the second operating signal from the engine and determines whether the conditions for disconnecting the second relay are met. If the conditions are met, the normally closed contact of the second relay is disconnected, and the starter stops operating.

[0014] Furthermore, it also includes: the first controller acquires the first operating signal of the engine, determines whether the condition for disconnecting the first relay is met, and if the condition is met, disconnects the first relay contact and the starter stops running.

[0015] Furthermore, the first operating signal is configured as the engine torque status, and the second operating signal is configured as the engine speed.

[0016] The beneficial effects of the technical solutions provided by the embodiments of the present invention include: 1. This invention adopts a dual-controller, dual-redundancy architecture. Each controller can independently cut off the starter power supply circuit when the exit condition is detected, effectively avoiding the risk of single-point failure caused by software logic abnormalities or drive circuit failures of a single controller, and significantly improving the safety and fault tolerance of the low-pressure start system of hybrid vehicle engines.

[0017] 2. This invention adopts a dual-relay series interlocking circuit. When the engine speed or engine torque reaches the preset condition, the starter power supply circuit can be cut off at the hardware level. This can avoid the failure of gear and armature structure damage caused by the engine dragging the starter at high speed. It can also ignore the continuous start operation signal and forcibly disconnect the starter power supply to avoid the starter coil being overheated and burned out due to long-term energization. This greatly improves the service life and electrical safety performance of the starting mechanism of hybrid vehicles. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the start-up control system for a hybrid vehicle.

[0019] In the diagram: 1: Second controller; 2: Power supply; 3: First relay; 4: First relay coil; 5: First relay contact; 6: Second relay; 7: Second relay coil; 8: Second relay contact; 9: Main relay; 10: Main relay coil; 11: Main relay contact; 12: Starter; 13: First controller. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 The first aspect of the present invention provides a hybrid vehicle starting control system, including a main relay 9, wherein two contacts of the main relay 9 are respectively connected to a starter 12 and a power supply 2; The main relay coil 10 is connected to the contacts of two relay groups connected in series. The controller is used to control the on / off state of the first relay 3 and the second relay 6 in two relay groups connected in series.

[0022] The controller includes a first controller 13 and a second controller 1; The first controller 13 controls the on / off state of the first relay 3 based on the acquired engine start condition signal; The second controller 1 controls the second relay 6 to switch on and off based on the acquired second engine operating signal; Specifically, the first controller 13 is a hybrid transmission control unit (HTCU), and the second controller 1 is an electronic control unit (ECU).

[0023] The HTCU includes P5, P6, P7, P8 and P9 interfaces. The P5 interface is connected to power supply 2, the P6 interface is connected to ground, and the P4 interface of the ECU is connected to the P9 interface via the CAN bus.

[0024] The ECU includes a P1 interface, a P2 interface, a P3 interface, and a P4 interface. The P1 interface is connected to power supply 2, and the P2 interface is connected to ground.

[0025] The first relay 3 is configured as a normally open contact relay; In this embodiment, the first relay 3 includes a first relay contact 5 and a first relay coil 4. The first relay contact 5 is connected to the P7 interface, and the two ends of the first relay coil 4 are respectively connected to the P8 interface and the ground terminal. The first relay contact 5 is a normally open contact, and its initial state is open. The second relay 6 is configured as a normally closed contact relay.

[0026] In this embodiment, the second relay 6 includes a second relay contact 8 and a second relay coil 7. The two ends of the second relay coil 7 are respectively connected to the P3 interface and the ground terminal. The second relay contact 8 is connected to the first relay contact 5. The second relay contact 8 is a normally closed contact, and its initial state is closed.

[0027] The main relay 9 is configured as a normally open contact relay.

[0028] In this embodiment, the main relay 9 includes a main relay contact 11 and a main relay coil 10. The main relay contact 11 is a normally open contact, and its initial state is open. The two ends of the main relay coil 10 are respectively connected to the second relay contact 8 and the ground terminal. The two ends of the main relay contact 11 are respectively connected to the starter 12 and the power supply 2. The two relay groups connected in series include a first relay 3 and a second relay 6; The first relay contact 5 of the first relay 3 is connected in series with the second relay contact 8 of the second relay 6.

[0029] The normally open first and second relays are connected in series to form a hardware AND gate. Only when both relays are conducting simultaneously can the main relay engage to start the starter motor. If a single controller malfunctions or sends an erroneous command, the circuit cannot be connected. This redundancy design prevents false starts.

[0030] The input terminal of the second relay coil 7 is connected to the coil interface terminal of the second controller 1, and the input terminal of the first relay coil 4 is connected to the coil interface terminal of the first controller 13.

[0031] The first controller 13 and the second controller 1 interact via CAN.

[0032] Specifically, CAN communication is a communication protocol that enables electronic control units to exchange data equally and in real time. CAN networks send information via broadcast, with each node autonomously selecting which to receive it, and are widely used in the automotive and industrial automation fields.

[0033] In this embodiment, the ECU and HTCU communicate via the CAN bus.

[0034] The ECU collects engine speed and torque data and uses it as a data transmitter to send torque data to the HTCU via the CAN network.

[0035] Example 2 A second aspect of this invention provides a hybrid vehicle start-up control method, comprising: After power-on, the first controller 13 and the second controller 1 are awakened, the second relay 6 is closed, and the first relay 3 is opened; In this embodiment, the driver turns the ignition key to the START position, the vehicle is powered on, and power supply 2 provides low-voltage power to the ECU and HTCU through the P1 interface and P5 interface respectively, and the ECU and HTCU are awakened.

[0036] When the P8 interface of the HTCU outputs a low level, there is no potential difference between the two ends of the first relay coil 4, so it cannot be energized and cannot generate electromagnetic attraction. The normally open first relay contact 5 remains in the initial open state.

[0037] When the P3 interface of the ECU outputs a low level, there is no potential difference between the two ends of the second relay coil 7, so it cannot be energized and cannot generate electromagnetic attraction. The normally closed second relay contact 8 remains in its initial closed state.

[0038] At this time, although the P7 interface has output a high level and the second relay contact 8 remains closed, the series circuit consisting of the P7 interface, the first relay contact 5, the second relay contact 8, the main relay coil 10 and the ground terminal is cut off by the first relay contact 5 because the first relay contact 5 is in the open state. The main relay coil 10 cannot be energized, and the normally open main relay contact 11 remains in the initial open state.

[0039] The first controller 13 acquires the engine start condition signal, and after determining that the start condition is met, it drives the first relay 3 to close, the main relay 9 to close under control, and the starter 12 starts. In this embodiment, engine start condition signals, including brake signals and gear signals, are collected and transmitted to the HTCU via a bus.

[0040] When the gear position signal is in park or neutral and the brake signal is effectively depressed, confirm that the vehicle is in a safe and stationary state and allow the engine to start.

[0041] When the startup conditions are met, the P8 interface of the HTCU switches from low level to high level, and the potential difference between the two ends of the first relay coil 4 is established and energized, generating electromagnetic attraction, which attracts the normally open first relay contact 5 to overcome the reset spring force and close; the P3 interface of the ECU remains at low level, the second relay coil 7 is not energized, and the normally closed second relay contact 8 continues to remain closed.

[0042] After the first relay contact 5 is closed, the series circuit consisting of the P7 interface, the first relay contact 5, the second relay contact 8, the main relay coil 10 and the ground terminal is fully connected. The high level output by the P7 interface of the HTCU passes through the closed first relay contact 5 and the closed second relay contact 8 to the main relay coil 10, and forms a complete current path through the ground terminal, so that the main relay coil 10 is energized.

[0043] When the main relay coil 10 is energized, it generates an electromagnetic attraction force, which attracts the normally open main relay contact 11 to close, so that the power supply 2 is connected to the starter 12 through the closed main relay contact 11. The starter 12 runs, and its drive pinion extends axially and meshes with the engine flywheel ring gear, transmitting torque to the crankshaft, driving the engine to rotate, and realizing the engine to start.

[0044] The second controller 1 acquires the second operating signal of the engine and determines whether the condition for disconnecting the second relay 6 is met. If the condition is met, the normally closed contact of the second relay 6 is disconnected, and the starter 12 stops running.

[0045] It also includes: the first controller 13 acquires the first operating signal of the engine, determines whether the condition for disconnecting the first relay 3 is met, and if the condition is met, disconnects the first relay contact 5, and the starter 12 stops running.

[0046] The second operating signal is configured as engine speed, and the first operating signal is configured as engine torque status.

[0047] In this embodiment, the ECU collects the engine speed signal and torque status signal spn899. After obtaining the engine torque status signal spn899, the ECU transmits the torque status signal to the HTCU via the CAN bus.

[0048] The condition for disconnecting the first relay 3 is that there is torque in the engine.

[0049] The condition for disconnecting the second relay 6 is that the engine speed is greater than or equal to 400 rpm.

[0050] Specifically, when the ECU detects an engine speed of 500 rpm, the ECU switches the P3 interface from low to high level. The second relay coil 7 is energized and generates electromagnetic attraction, causing the normally closed second relay contact 8 to open. After the second relay contact 8 opens, the series circuit formed by the P7 interface, the first relay contact 5, the second relay contact 8, the main relay coil 10, and ground is interrupted at the second relay contact 8. The main relay coil 10 is de-energized, the electromagnetic attraction disappears, and the normally open main relay contact 11 opens under the action of the return spring. The main power supply circuit between the power supply 2 and the starter 12 is then cut off, and the starter 12 stops operating due to power failure.

[0051] The engine torque status signal spn899 collected by the ECU is transmitted to the HTCU via the CAN network. When the HTCU detects a torque status signal value of 1, it immediately switches its P8 interface from high to low level. The first relay coil 4 is de-energized, the electromagnetic attraction disappears, and the normally open first relay contact 5 opens. After the first relay contact 5 opens, the above-mentioned series circuit is cut off at the first relay contact 5. The main relay coil 10 is also de-energized, and the normally open main relay contact 11 opens. The main power supply circuit between the power supply 2 and the starter 12 is cut off, and the starter 12 stops operating due to power failure.

[0052] The two power-off mechanisms described above are executed independently by the ECU and HTCU, respectively. Through the redundant power-off design using dual parameters of speed and torque and dual controllers of the ECU and HTCU, even if one path detects or controls an abnormality, the other path can still independently complete the power-off protection of the starter 12. This mechanism can effectively prevent the starter 12 from overheating and burning out due to prolonged continuous power supply after the engine has started successfully. It can also prevent the high-speed rotating engine flywheel from dragging the starter 12 in the opposite direction and causing it to overspeed and be damaged if the drive gear of the starter 12 becomes mechanically stuck and fails to disengage from the flywheel ring gear in time. This significantly improves the safety and reliability of the low-voltage starting system of hybrid vehicles.

[0053] Example 3 This embodiment, based on the system described in Embodiment 1, further illustrates the protective function of the system in preventing the starter motor 12 from being energized for an extended period of time.

[0054] If the driver keeps the ignition key in the START position for an extended period after starting the engine, and a short circuit occurs due to aging wiring, the starter motor 12 may remain energized for several seconds or even minutes. Prolonged energization can cause the coil to overheat, the insulation to melt, and ultimately burn out or even cause a fire.

[0055] Regardless of whether the start command persists, once the engine speed exceeds the preset threshold, the ECU directly disconnects the second relay 6. This is a forced disconnection based on the engine status, with higher priority than the driver's start command, thereby solving the problem of the starter motor 12 being energized for a long time due to the persistent presence of the command caused by a short circuit.

[0056] Example 4 This embodiment, based on the system described in Embodiment 1, further illustrates the protective function of the system in preventing repeated starts caused by misjudgment of engine status.

[0057] If the engine shuts off and starts very frequently, the HTCU's logic becomes disordered. For example, the engine is decelerating and coasting but has not yet come to a complete stop, but the HTCU mistakenly thinks it needs to be started and engages the starter motor 12.

[0058] The two relay groups connected in series form an AND gate logic. The starter 12 can only work when the first relay is activated by the HTCU and the second relay remains normally closed, that is, when the engine speed is greater than the preset threshold and the torque condition is met simultaneously. This adds an interlock condition: if the torque status signal value is not 1, even if the HTCU mistakenly sends a command to activate the first relay 3, the starting circuit will still be closed because the second relay 6 has been forcibly disconnected by the ECU, thus fundamentally preventing mis-engagement during high-speed operation.

[0059] Example 5 This embodiment, based on the system described in Embodiment 1, further illustrates the protective function of the system in preventing damage to the starter motor 12 from reverse drag.

[0060] After the engine has been successfully ignited, if the gear of starter 12 does not disengage from the engine flywheel ring gear in time, the high speed of the engine will in turn drive the armature shaft of starter 12 to rotate at an ultra-high speed. This speed usually far exceeds the design limit of starter 12, which will cause starter 12 to be damaged.

[0061] This invention monitors engine speed in real time via the ECU. When the engine speed exceeds a threshold, it determines that the start-up is successful and immediately disconnects the second relay 6, thus forcibly cutting off the power supply 2 to the starter 12. Even if the electromagnetic switch of the starter 12 is stuck in the engaged position and there is no power input 2, the starter 12 cannot be reversed to rotate, thereby achieving hardware-level power-off protection.

[0062] The contents not described in detail in this specification are prior art known to those skilled in the art. Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0063] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0064] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0065] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

Claims

1. A hybrid vehicle starting control system, characterized in that, Includes a main relay, whose two contacts are respectively connected to the starter motor and the power supply; The main relay coil is connected to the contacts of two relay groups connected in series. The controller is used to control the on / off state of the first and second relays in two relay groups connected in series.

2. The hybrid vehicle start-up control system according to claim 1, characterized in that, The two relay groups connected in series include a first relay and a second relay; The first relay contact of the first relay is connected in series with the second relay contact of the second relay.

3. The hybrid vehicle start-up control system according to claim 1 or 2, characterized in that, The controller includes a first controller and a second controller; The first controller controls the on / off state of the first relay based on the acquired engine start condition signal; The second controller controls the on / off state of the second relay based on the acquired second engine operating signal.

4. The hybrid vehicle start-up control system according to claim 2, characterized in that, The first relay is configured as a normally open contact relay; The second relay is configured as a normally closed contact relay.

5. The hybrid vehicle start-up control system according to claim 1, characterized in that, The main relay is configured as a normally open contact relay.

6. The hybrid vehicle start-up control system according to claim 3, characterized in that, The input terminal of the second relay coil is connected to the coil interface terminal of the second controller, and the input terminal of the first relay coil is connected to the coil interface terminal of the first controller.

7. The hybrid vehicle start-up control system according to claim 3, characterized in that, The first controller and the second controller interact via CAN.

8. A method for starting control of a hybrid vehicle, characterized in that, include: Upon power-up, the first and second controllers are activated, the second relay closes, and the first relay opens. The first controller receives the engine starting condition signal, determines that the starting condition is met, drives the first relay to close, the main relay to close under control, and the starter motor starts. The second controller acquires the second operating signal from the engine and determines whether the conditions for disconnecting the second relay are met. If the conditions are met, the normally closed contact of the second relay is disconnected, and the starter stops operating.

9. The hybrid vehicle start-up control method according to claim 8, characterized in that, Also includes: The first controller receives the first operating signal from the engine and determines whether the condition for disconnecting the first relay is met. If the condition is met, the first relay contact is disconnected, and the starter stops operating.

10. The hybrid vehicle start-up control method according to claim 9, characterized in that, The first operating signal is configured as engine torque status, and the second operating signal is configured as engine speed.

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