Novel gear locking control method for automatic gear new energy vehicle

Abstract

The invention relates to the technical field of new energy vehicle control, and particularly discloses a novel gear locking control method for an automatic transmission new energy vehicle, which comprises the following steps of: establishing a gear locking identification and execution system which comprises a transmission control unit (TCU), an electronic gear shifter, a vehicle control unit (VCU) and a motor control unit (MCU); an automatic gear lever climbing function key of the electronic gear shifter is redefined as a gear locking key; when the vehicle is in the D-gear driving state and the gear locking key is triggered, a gear locking instruction is sent to a vehicle control unit VCU; the VCU is set to respond to the gear locking instruction, stop the automatic gear shifting logic and lock the current gear of the gearbox; the existing hardware state of the vehicle is utilized, the gear locking function can be achieved by updating the VCU program, and the implementation cost is low; and a safety protection mechanism (forced upshift and forced downshift) is arranged, so that the safety is high, the operation is convenient, and the operability is high.

Description

Technical Field

[0001] This invention belongs to the field of new energy vehicle control technology, specifically relating to a novel gear lock control method for automatic transmission new energy vehicles. Background Technology

[0002] Modern new energy commercial vehicles generally use electronic gear shifters, and the shifting process is as follows: When the driver operates the electronic shifter to the target gear, the electronic shifter sends a message signal or electrical signal to the vehicle control unit (VCU) via the CAN bus or low-voltage wiring harness. The VCU determines and issues shift commands to the Transmission Control Unit (TCU). Ultimately, the TCU controls the air circuit to achieve gear shifting via the mechanical structure of the transmission.

[0003] Automatic transmission electric vehicles face certain limitations in complex market environments, particularly during rapid acceleration for overtaking and steep inclines. Their shifting speed and the immediacy of power delivery are not as immediate as those of experienced drivers operating manual transmission vehicles. Especially when climbing hills, the different gear ratios in multi-speed transmission vehicles result in significant variations in the driving force delivered by the motor to the wheels. This can lead to situations where a lower gear provides sufficient power for acceleration uphill, prompting the vehicle to automatically upshift. However, the resulting wheel-end driving force may be insufficient to maintain a high speed, causing the vehicle to decelerate and automatically downshift. This results in frequent automatic gear changes during uphill climbs. This not only affects the lifespan of the transmission but also negatively impacts vehicle performance and driving safety.

[0004] To improve the operability of automatic transmissions, a manual / automatic shift lever is used in the initial vehicle design, allowing drivers to switch between manual and automatic modes via buttons on the lever. This solution provides drivers with greater operational freedom; however, it cannot meet the temporary needs of customers or the lack of a matching manual / automatic shift lever, and the redevelopment cycle cannot meet design requirements. Therefore, a novel gear lock control method for automatic transmission new energy vehicles is needed to solve the aforementioned technical problems in existing new energy commercial vehicles. Summary of the Invention

[0005] The purpose of this invention is to provide a novel gear lock control method for automatic transmission new energy vehicles. Based on the existing hardware of the actual vehicle, without increasing additional costs, this solution is proposed to improve the driving operability of automatic transmission vehicles while ensuring vehicle safety.

[0006] To address the aforementioned problems in the existing technology, the technical solution adopted by this invention is: a novel gear lock control method for automatic transmission new energy vehicles, comprising the following steps:

[0007] S1. Build a gear lock recognition and execution system, which includes a transmission controller TCU, an electronic shifter, a vehicle controller VCU, and a motor controller MCU.

[0008] S2. The automatic gear shift lever hill-climbing function button of the electronic gear shifter has been redefined as the gear lock button;

[0009] S3. When the vehicle is in D gear and the gear lock button is triggered, a gear lock command is sent to the vehicle control unit (VCU).

[0010] S4. The vehicle control unit (VCU) is set to respond to the gear lock command, stop the automatic shifting logic, and lock the current gear of the transmission.

[0011] Preferably, in step S3, when the vehicle is in D gear, the driver presses the hill-climbing function button, and the vehicle controller (VCU) receives the gear lever signal and interprets it as a gear lock command.

[0012] Preferably, in step S4, the vehicle control unit (VCU) sends a command to the transmission control unit (TCU), which then terminates the original automatic shifting logic and locks the current gear for driving.

[0013] Preferably, the gear lock is released when the gear lock button is triggered again, the vehicle forced downshift function is triggered, or the vehicle forced upshift function is triggered.

[0014] Preferably, the vehicle forced downshift function is triggered when the vehicle controller (VCU) detects that the driver is driving at full throttle and the current vehicle speed is less than the minimum speed corresponding to the current gear. In this case, the vehicle forced downshift function is triggered, and the vehicle controller (VCU) prioritizes the downshift operation and releases the gear lock.

[0015] Preferably, the vehicle forced upshift function is triggered when the vehicle controller (VCU) detects that the motor exceeds a preset safety threshold. In this case, the vehicle forced upshift function is triggered, and the VCU performs a forced upshift and releases the gear lock.

[0016] The beneficial effects of this invention are as follows:

[0017] The novel gear lock control method for automatic transmission new energy vehicles designed in this invention is low-cost and high-yield. It does not require the addition or replacement of vehicle parts. The gear lock function can be realized by updating the VCU program using the existing hardware of the vehicle, and the implementation cost is low.

[0018] This invention presents a novel gear locking control method for automatic transmission new energy vehicles, which enhances vehicle adaptability. When the vehicle is stuck in muddy conditions, the driver can lock the gear to prevent automatic upshifting from causing insufficient wheel-end drive torque. When descending long slopes, locking the gear to a low or medium gear enhances energy recovery to achieve reverse towing of the vehicle and avoids overheating of brake pads due to frequent braking on long downhill slopes. When climbing hills with heavy loads, locking the gear in a specific position prevents the VCU from making unnecessary gear shifts due to speed fluctuations, ensuring stable power output.

[0019] The novel gear lock control method for automatic transmission new energy vehicles designed in this invention has high safety and is equipped with a safety protection mechanism (forced upshifting and forced downshifting) to prevent damage to the gearbox and motor due to misoperation or prolonged high-speed operation of the motor.

[0020] The novel gear locking control method for automatic transmission new energy vehicles designed in this invention is convenient to operate and highly operable. This method is compatible with the operability of manual transmissions where the gear can be selected independently. At the same time, it achieves convenient forced gear switching through safety protection measures. For the driver, it only requires pressing the gear lock button, which has a low learning cost, is easy to operate, and is easy to promote. Attached Figure Description

[0021] Figure 1 This is a block diagram illustrating the working principle of a novel gear lock control method for automatic transmission new energy vehicles.

[0022] Figure 2 This is a control logic flowchart for a novel gear lock control method used in automatic transmission new energy vehicles.

[0023] Figure 3 This is a schematic diagram of a new gear lock control system for automatic transmission new energy vehicles. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and reference numerals.

[0025] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] The terms “first,” “second,” “third,” etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0027] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] like Figures 1-3 As shown, a novel gear lock control method for automatic transmission new energy vehicles is proposed. The implementation of this method requires the construction of a gear lock recognition and execution system, which consists of multiple modules including: a vehicle control unit (VCU) (driver intent recognition module, information conversion and processing module, command issuance module, and safety protection module), a transmission control unit (TCU), a motor control unit (MCU) (execution module), and a status display module (instrument). The relevant components in the system are as follows:

[0030] The vehicle's original electronic gear shifter automatic gear lever, equipped with a hill-climbing gear button or a hill-climbing gear button configured in the vehicle; the vehicle's original automatic transmission assembly; transmission controller TCU; vehicle controller VCU; motor controller MCU.

[0031] Implementation of the method: When the vehicle is in D gear, the driver presses the "climb gear" button. The VCU receives the gear lever signal and interprets it as a gear lock command, controlling the TCU to terminate the original automatic shifting logic and lock the current gear for driving. The implementation process involves the following situations (taking a four-speed gearbox as an example):

[0032] Lock and enter:

[0033] (1) The vehicle is currently under high pressure and stationary. The driver presses the brake pedal and simultaneously moves the gear lever ND to engage D2 gear. Press the lock gear button to switch to D1 gear and lock the first gear.

[0034] (2) The vehicle is currently in a high-voltage, driving state. The driver can press the lock button at any time to lock the current gear.

[0035] (3) When the vehicle is locked in gear and has been driven to a stop, in order to ensure the vehicle can start again and to protect the mechanical structure of the gearbox, the vehicle should be controlled to D1 gear to start when the vehicle is locked in gear.

[0036] Lock released:

[0037] (1) The vehicle is currently in a high-voltage, stationary, and locked state. The driver presses the lock gear button to switch from D1 gear to D2 gear and release the gear lock.

[0038] (2) The vehicle is currently in a high-voltage, driving, and locked state. The driver can press the lock button at any time to unlock the current gear. The VCU will then find a suitable gear to continue driving based on the current vehicle status.

[0039] (3) The vehicle is currently in a high-voltage, driving, and locked state. The driver presses the accelerator pedal deeply, and the current vehicle speed is less than the minimum vehicle speed threshold set for the current gear. This triggers a forced downshift judgment. At this time, the vehicle is driven by forcibly downshifting one gear according to the current gear.

[0040] (4) The vehicle is currently in a high-voltage, driving, and locked state. If the vehicle is on a heavily loaded downhill section, the energy recovery intensity cannot meet the vehicle deceleration. When the actual speed of the motor exceeds the safe value, the VCU will perform a forced upshift to protect the motor and gearbox.

[0041] Electronic shifter: An electronic device used to receive the driver's gear shifting request. It converts the driver's actions into digital message signals and sends them to the CAN communication network. The VCU receives the signals and issues the gear shifting command, thereby completing the transmission of the driver's intention.

[0042] Vehicle Control Unit (VCU): As the core control unit of a new energy vehicle, it is equivalent to the vehicle's "brain" and "nerve center". It transmits and receives signals through the CAN network or controller hardware interface, coordinating the operation of all components in the vehicle to realize functions such as power control, energy management, safety protection, and fault handling.

[0043] Transmission Control Unit (TCU): One of the core control units of a vehicle's transmission system, it is specifically responsible for intelligent and precise control of the transmission. Based on the driver's intentions and the vehicle's real-time status, it uses complex decision-making logic to select the most appropriate gear and shift timing, and translates the decisions into precise commands to the transmission's actuators.

[0044] Motor Control Unit (MCU): The core electronic control unit that controls the drive motor to operate in a set direction, speed, torque, and mode. In modern electric vehicles, it converts the DC power supplied by the battery into the three-phase AC power required by the drive motor and precisely controls its frequency, voltage, and phase, thereby achieving precise regulation of the motor's torque and speed.

[0045] Instrumentation Circuit (IC): The "brain" and "visual engine" of a vehicle's instrument panel (digital LCD instrument cluster). It is responsible for processing data from various vehicle systems and converting and synthesizing it into graphics, numbers, and animations, which are then presented to the driver on the screen in real time, clearly, and reliably.

[0046] With the help of Figure 1 The block diagram of the system's working principle illustrates the relevant systems and signal flow involved in this invention: When the driver operates the brake pedal and the lock-up button (i.e., the original hill-climbing button), the electronic shifter transmits the lock-up request to the VCU via the CAN bus. The VCU integrates the vehicle's "brake pedal" and "motor speed" states, sends the target gear to the TCU, and simultaneously controls the motor to enable the TCU's gear-shifting action. After gear shifting is completed, the current gear is locked, and the gear status is sent to the instrument panel for display.

[0047] Figure 2 The control logic flowchart of this invention is explained as follows: Initially, the vehicle is in D gear, and the dynamic / static status of the vehicle needs to be determined. If the vehicle is stationary, pressing the gear lock button causes the VCU to consider the vehicle's status, issue a D2 to D1 shift command, and perform the gear lock operation. Pressing the gear lock button again switches the gear from D1 to D2. If the vehicle is moving, pressing the gear lock button causes the VCU to lock the current gear based on the current vehicle status. Pressing the gear lock button again releases the gear lock, and the VCU finds a suitable gear based on the current vehicle status and issues a command, which the TCU executes. During locked-gear driving, the vehicle status needs to be continuously monitored to ensure vehicle safety during the gear lock function. If the vehicle is driving in locked gear under heavy load on a long downhill slope, and the motor exceeds its peak speed for 3 seconds, the gear lock mechanism is disengaged and a forced upshift is initiated. If the vehicle is driving in locked gear under heavy load on an uphill slope, and the VCU detects that the vehicle is currently at full throttle but the speed is below the minimum speed set for the current locked gear, the gear lock mechanism is disengaged and a forced downshift is initiated.

[0048] Figure 3 The following is a schematic diagram of the relevant system modules of this invention, explained as follows:

[0049] Driver Intent Recognition Module: The driver operates the uphill gear button on the gear lever, and the electronic gear shifter recognizes the driver's intent and sends a request to the VCU.

[0050] Information conversion and processing module, instruction issuance module: When the VCU receives the electronic shifter request signal, it converts the hill-climbing gear request instruction into a gear lock instruction and issues the gear position instruction according to the gear lock instruction.

[0051] Execution module: TCU and MCU serve as execution units. TCU performs gear shifting actions according to VCU instructions, and MCU responds to VCU instructions to enable the motor and execute torque.

[0052] Status display module: The IC acts as a status display module, receiving status commands from the VCU to display the current vehicle gear status.

[0053] Safety Protection Module: As the core component of the safety protection module, the VCU will enter the safety protection module to force upshift or downshift and exit the locked state when the motor is overloaded or the vehicle's driving force is insufficient in the locked state.

[0054] The following application scenarios will exist after the implementation of this invention:

[0055] Scenario 1: When the vehicle is stationary, perform the ND operation on the electronic gear shifter. Taking a four-speed gearbox as an example, the default starting gear is D2. Pressing the lock button shifts the gear from D2 to D1 and locks it in D1. Pressing the lock button again shifts the gear back from D1 to D2. In other words, when the vehicle is stationary, you can switch between D2 and D1 by operating the lock button, and locking the gear is performed simultaneously when switching to D1.

[0056] Scenario 2: When the vehicle is in Drive (D) mode, pressing the lock button on the electronic gear shifter will lock the current gear in the VCU, preventing upshifting or downshifting while the vehicle is in motion. Pressing the lock button again will release the lock, and the VCU will find a suitable gear based on the current vehicle status and send a command to the TCU to execute the gear shift.

[0057] Scenario 3: When the vehicle is on a long downhill section and driving in D gear, pressing the lock button on the electronic shifter will lock the current gear, preventing the vehicle from upshifting or downshifting while driving. Simultaneously, enhanced energy recovery will be used to reverse-drag the motor, preventing overspeeding during downhill driving, thus achieving the gear locking function.

[0058] The following security risks exist after the implementation of this invention, therefore corresponding security mechanisms are designed:

[0059] Risk 1: In the locked state, energy recovery may not be sufficient to reduce vehicle speed on a long downhill section under heavy load, leading to motor overspeed.

[0060] Safety mechanism: When the motor speed exceeds the threshold for 3 consecutive seconds in the locked state, the VCU will ignore the locked command and force upshift to exit the locked mode in order to protect the powertrain.

[0061] Risk 2: In the locked gear state, improper operation of maintaining a high gear while going uphill on a heavily loaded road may lead to insufficient power.

[0062] Safety mechanism: When the VCU detects that the vehicle is currently in a high gear with full throttle and the vehicle speed is less than the set minimum speed for that gear, the VCU ignores the gear lock command, forcibly downshifts one gear and disengages from the gear lock to ensure vehicle power output.

[0063] This invention updates the existing VCU internal software program, redefining the original hill-climbing gear button as a gear lock function button, thereby realizing a new gear lock control method for automatic transmissions. This method improves the safety and operability of automatic transmissions without requiring changes to vehicle hardware and incurring no additional costs.

[0064] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A novel gear lock control method for automatic transmission new energy vehicles, characterized in that, Includes the following steps: S1. Build a gear lock recognition and execution system, which includes a transmission controller TCU, an electronic shifter, a vehicle controller VCU, and a motor controller MCU. S2. The automatic gear shift lever hill-climbing function button of the electronic gear shifter has been redefined as the gear lock button; S3. When the vehicle is in D gear and the gear lock button is triggered, a gear lock command is sent to the vehicle control unit (VCU). S4. The vehicle control unit (VCU) is set to respond to the gear lock command, stop the automatic shifting logic, and lock the current gear of the transmission.

2. The novel gear locking control method for automatic transmission new energy vehicles according to claim 1, characterized in that, In step S3, when the vehicle is in D gear, the driver presses the hill-climbing function button, and the vehicle controller (VCU) receives the gear lever signal and interprets it as a gear lock command.

3. The novel gear locking control method for automatic transmission new energy vehicles according to claim 2, characterized in that, In step S4, the vehicle control unit (VCU) sends a command to the transmission control unit (TCU), which then terminates the original automatic shifting logic and locks the current gear for driving.

4. The novel gear locking control method for automatic transmission new energy vehicles according to claim 3, characterized in that, The gear lock is released when the gear lock button is triggered again, the vehicle's forced downshift function is triggered, or the vehicle's forced upshift function is triggered.

5. The novel gear locking control method for automatic transmission new energy vehicles according to claim 4, characterized in that, The vehicle forced downshift function is triggered when the vehicle controller (VCU) detects that the driver is driving at full throttle and the current vehicle speed is less than the minimum speed corresponding to the current gear. The vehicle forced downshift function is then triggered, and the VCU prioritizes the downshift operation and releases the gear lock.

6. The novel gear lock control method for automatic transmission new energy vehicles according to claim 4, characterized in that, The vehicle forced upshift function is triggered when the vehicle controller (VCU) detects that the motor exceeds a preset safety threshold. In this case, the vehicle forced upshift function is triggered, and the VCU performs a forced upshift and releases the gear lock.

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