An electrically powered trailer torque follow control system

Abstract

The utility model provides a kind of electric trailer torque follow-up control system, comprising: the tractor of retaining original engine control unit and signal output interface;Carry driving motor and energy storage device's electric drive trailer;Electronic controller is deployed on electric drive trailer, its built-in storage motor control offline interpolation table;For transmitting engine demand torque signal, engine speed signal, accelerator pedal opening degree signal communication bus;Wherein, the electronic controller is configured as: 1) according to received accelerator pedal opening degree signal and vehicle speed signal, query the motor control offline interpolation table to generate motor torque instruction;2) control the driving motor output and engine torque keep preset proportion range's torque value.The utility model does not need to transform original vehicle control circuit, adapts to a variety of power type tractor;Motor control offline interpolation table built-in electronic controller can also be customized for different vehicle power parameters, support single axle or multi-axle electric drive trailer rapid deployment.

Description

Technical Field

[0001] This utility model relates to the field of hybrid vehicle control technology, and in particular to an electric trailer torque following control system. Background Technology

[0002] Hybrid technology can improve engine fuel economy and enhance overall vehicle energy efficiency by recovering braking energy. Research on hybrid powertrain configurations in the heavy-duty truck sector primarily focuses on parallel, series, and series-parallel arrangements. Considering the unique characteristics of articulated vehicle configurations, the traditional unpowered trailer negatively impacts overall longitudinal dynamics and lateral stability. Therefore, by integrating a powertrain onto the trailer, a P4 hybrid configuration can be created, enabling the regulation of overall vehicle power distribution and enhancing handling. This configuration allows for the electrification of existing diesel heavy-duty trucks without altering the tractor's original powertrain, thereby reducing fuel consumption and carbon emissions, demonstrating promising development prospects.

[0003] Currently, there is limited research on powertrain control strategies for this powertrain configuration. Most existing control strategies are rule-based, offering advantages such as low real-time computational load and strong robustness, but they often rely on engineers' experience for calibration and are specific to particular vehicle models. On the other hand, adaptive control strategies can provide more flexible responses, but due to limitations in current computing power and data acquisition technology, these strategies have undergone necessary simplifications, resulting in longer optimization cycles and a lack of universality across different vehicle models.

[0004] This unique configuration possesses significantly different characteristics and application ranges compared to traditional configurations. Therefore, the strategies used in traditional hybrid powertrains cannot be completely copied. Its control strategy still requires the following considerations: 1) Due to the non-integrated structure at the hinge, the strategy needs to minimize frequent and drastic stress changes at the hinge point. This necessitates coordination between the electric drive control scheme and the power output of the tractor unit. 2) The independence of the electric trailer allows for flexible matching of different power parameters and even power configurations. Therefore, the control strategy needs to be adjusted for the matched tractor unit to achieve optimal energy consumption and driving smoothness. 3) Heavy-duty truck operating scenarios are typically relatively fixed, making it feasible to customize energy management strategies based on specific working conditions. Plug-in heavy-duty trucks have the ability to establish standardized charging procedures and can plan their State of Charge (SOC) to achieve good energy efficiency.

[0005] In existing technologies, the electric drive control technology for trailers generally manifests as follows: 1) Sharing the same energy storage device, with power output distributed between the tractor and trailer. For example, patent CN201921122581.0 describes a pure electric tractor unit equipped with an electric-drive trailer. The tractor unit's power module provides electricity to the entire vehicle, and the power distribution module controls the power distribution of the entire vehicle, reducing braking energy loss, reducing acceleration time, and increasing climbing ability. However, while the distributed power output between the tractor and trailer in this patent can make the energy distribution of the entire vehicle more uniform and save energy storage costs, it requires a tractor unit with a power storage device and the transmission and control of energy between the tractor and trailer. This solution places additional requirements on the tractor unit, increasing the difficulty and cost of tractor unit modification, and is not suitable for current traditional tractor and trailer configurations. Furthermore, its power distribution strategy has poor adaptability to operating conditions, and because it is parameter calibration for a specific vehicle model, it is difficult to guarantee universality. 2) The trailer's electric drive system provides power by following the movement of the tractor unit, as described in patent CN201821938559.9, a trailer and its novel trailer. The registration includes an electric drive system for driving the trailer, a follow-up system for detecting the movement of the tractor unit, and a control device for controlling the electric drive system. When the follow-up system detects that the tractor unit is moving forward, the electric drive system drives the trailer forward; when the follow-up system detects that the tractor unit is accelerating, the electric drive force of the electric drive system increases, causing the trailer to accelerate; when the follow-up system detects that the tractor unit is braking, the electric drive force of the electric drive system decreases, causing the trailer to decelerate. In this technology, the trailer's electric drive system, which provides power by following the movement of the tractor unit, does not require extensive modifications to the tractor unit and has simple and reliable control logic. However, this also limits the possibility of more precise control and more complex power coordination, thus failing to achieve optimal overall vehicle energy consumption. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of existing technical solutions and propose a control system that can not only ensure the coordinated torque output of the main and trailer power sources, but also achieve rapid and automatic strategy optimization for different working conditions and vehicle models.

[0007] To achieve the above objectives, this utility model proposes an electric trailer torque following control system, comprising:

[0008] Tractor: Retain the original engine control unit and signal output interface, and continue to be responsible for the analysis and forwarding of the vehicle's power requests;

[0009] Electric trailer: equipped with a drive motor and energy storage device;

[0010] Electronic controller: Deployed on the electric drive trailer, with built-in storage of offline interpolation tables for motor control;

[0011] Communication bus: connects the tractor vehicle and the electronic controller, and is used to transmit engine torque demand signal, engine speed signal, accelerator pedal opening signal, brake pedal opening signal and gearbox gear signal;

[0012] The electronic controller is configured as follows:

[0013] 1) Based on the received engine torque demand signal, engine speed signal, accelerator pedal opening signal, brake pedal opening signal and gearbox gear signal, query the offline interpolation table of motor control to generate motor torque command;

[0014] 2) Control the output torque value of the drive motor to maintain a preset ratio range with the engine torque.

[0015] Furthermore, the tractor unit's overall controller collects information such as the driver's accelerator pedal opening, brake pedal opening, gearbox gear position, current engine speed, and current torque demand via the CAN bus. These signals are used to drive the tractor unit's own engine controller to output power, ensuring the tractor engine continues to output the required torque according to the vehicle controller's instructions, without altering the control strategy due to the presence of the trailer drive motor. Simultaneously, these signals are sent to the electric trailer's electronic controller via the bus, serving as input for coordinated power control of the trailer drive motor. The electric trailer's electronic controller, as an independent control unit, determines the target output torque and start / stop status of the trailer motor based on the received tractor unit operating status signals and an electric trailer power control interpolation table. The interpolation table is calibrated during the design phase based on parameters such as engine torque demand, speed, gear position, and pedal opening to achieve high-precision torque tracking output. During actual operation, the trailer controller quickly obtains the target torque command through a lookup table and sends this torque request to the trailer motor electronic controller. When the tractor unit accelerates, the trailer motor can provide positive drive torque for power compensation; when braking, the trailer motor can switch to energy regenerative braking mode to assist deceleration. This strategy helps reduce the load on the tractor unit and improve the vehicle's acceleration response and braking stability.

[0016] Furthermore, the preset ratio is the motor output torque / engine output torque converted to the wheel end. The minimum value of this value is 0, and the maximum value is the trailer's full load weight / the tractor's curb weight.

[0017] Furthermore, the communication bus is a CAN bus, FlexRay bus, or Ethernet protocol; the signal output interface transmits the gearbox gear position signal and brake pedal opening signal through the communication bus.

[0018] Furthermore, the electric drive trailer is a single-axle or multi-axle electric drive axle configuration, and the power type of the tractor is one of diesel engine, natural gas engine, hydrogen fuel engine or other fuel engine.

[0019] Furthermore, the electronic controller adopts a centralized or distributed topology; the energy storage device is a lithium-ion battery pack or a supercapacitor pack.

[0020] Furthermore, the offline interpolation table for motor control stores the mapping relationship between vehicle speed, accelerator pedal opening, and motor torque value; the mapping relationship is generated through optimization of vehicle operating data and is matched with the power parameters of the tractor.

[0021] Based on the electric trailer torque following control system of this utility model, the method for implementing electric trailer torque following control strategy and automatic optimization includes the following steps:

[0022] S1: Collect vehicle speed and wheel-end torque signals under vehicle operating conditions to generate a vehicle power demand dataset;

[0023] S2: Based on the vehicle demand power dataset, calculate the vehicle power density probability distribution feature dataset using non-parametric statistical methods;

[0024] S3: With the constraint that the engine torque and the motor torque are in a positive proportional range, and with the weighted total energy utilization efficiency as the optimization objective, a recursive optimization algorithm is used to generate an offline interpolation table for motor control, based on the power density probability distribution feature dataset.

[0025] S4: Execute the automatic optimization and calibration process:

[0026] S4.1: Construct an energy consumption prediction model, input vehicle parameters and operating conditions, and output the predicted power consumption;

[0027] S4.2: Optimize the adjustable parameter set of the energy consumption prediction model using a genetic algorithm until the error between the predicted power consumption and the actual power consumption is less than a threshold.

[0028] S4.3: Adjust the oil-electricity weight factor based on Bayesian optimization, and update the offline interpolation table for motor control in combination with the calibrated energy consumption prediction model;

[0029] S4.4: Repeat step S4.3 until the estimated power consumption reaches the expected power consumption, and output the final offline interpolation table for motor control.

[0030] In step S4, an automatic calibration process suitable for rapid adaptation of multiple vehicle models is developed by combining genetic algorithms with Bayesian optimization, which significantly shortens the optimization and calibration time of the control strategy and reduces experimental costs.

[0031] Furthermore, in step S2, the nonparametric statistical method is one of kernel density estimation, nearest neighbor estimation, or wavelet density estimation; special operating point is filtered by setting a bandwidth parameter, and the bandwidth parameter is dynamically adjusted according to the dispersion of the operating data.

[0032] Furthermore, in step S4.2, the adjustable parameter set includes at least one of the following: power system efficiency parameters, rolling resistance coefficient, and air resistance coefficient.

[0033] Furthermore, in step S4.3, the Bayesian optimization is performed as follows: a Gaussian process regression model is constructed using Bayesian optimization to fit the functional relationship between the oil-electricity weight factor and the estimated power consumption; the next oil-electricity weight factor sampling point is selected by maximizing the acquisition function.

[0034] Furthermore, in step S3, the recursive optimization algorithm is one of particle swarm optimization or simulated annealing; the Bayesian optimization in step S5.3 can be replaced by a tree-based Parzen estimator or an entropy search algorithm.

[0035] Furthermore, the electric trailer torque following control strategy and automatic optimization method can be compatible with multi-axle electric drive trailers (single-axle / dual-axle drive) through a parameterized interface, and there are no requirements for the power type of the tractor (diesel / natural gas / hydrogen fuel / other fuels).

[0036] Compared with the prior art, the advantages of this utility model are:

[0037] 1. This utility model directly obtains the engine torque requirement and pedal signal of the tractor through the communication bus without modifying the original vehicle control circuit. It is compatible with tractors of various power types such as diesel, natural gas, hydrogen fuel, and other fuels. The offline interpolation table for motor control built into the electronic controller can also be customized for the power parameters of different models. It supports the rapid deployment of single-axle or multi-axle electric drive trailers and has strong structural compatibility.

[0038] 2. In this utility model system, the electric motor torque output is constrained to maintain a proportional range with the engine torque by the electronic controller, which avoids excessive stress at the hinge point from the physical structure and solves the risk of longitudinal dynamic instability caused by the non-rigid connection between the main vehicle and the trailer. It also uses a distributed hardware topology to ensure that the electric drive trailer can still perform torque following braking when the original tractor braking system fails, which has safety and reliability.

[0039] 3. This utility model utilizes the native interface of the tractor vehicle to collect information and adopts the standardized CAN / FlexRay communication protocol to reduce the cost of custom wiring harnesses.

[0040] 4. By incorporating the power density probability distribution characteristics into the optimization framework of the torque distribution strategy through this utility model system, the system achieves a synergistic improvement in vehicle energy consumption optimization and articulation safety while constraining the engine and motor torques to maintain a positive proportional range.

[0041] 5. The control system of this utility model realizes automatic optimization of the calibration process, reduces the experimental cost and time cost of traditional solutions, supports rapid desktop calibration, and does not rely on engineering experience.

[0042] 6. This utility model takes into account the problem of matching trailers with tractors with different power parameters, ensuring that the best control strategy can be quickly obtained for vehicles with different parameters. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the operating framework of the electric trailer torque following control system of this utility model;

[0044] Figure 2 This is a schematic diagram of the hardware connection structure of the electric trailer torque following control system in this embodiment;

[0045] Figure 3 This is a schematic diagram illustrating the control strategy and automatic optimization method of the electric trailer torque following control system based on this utility model;

[0046] Figure 2 In the middle, 1-load-bearing axle, 2-engine, 3-clutch, 4-gearbox, 5-drive axle, 6-brake, 7-engine controller, 8-gearbox controller, 9-vehicle controller, 10-main and trailer mechanical brake distribution controller, 11-pneumatic proportional control valve, 12-battery energy management system, 13-power battery, 14-trailer drive motor, 15-trailer power controller, 16-motor electronic controller, 17-electric drive axle. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be further described below.

[0048] This embodiment proposes a torque following control system for electric trailers, such as... Figure 1 As shown, it includes:

[0049] Tractor: Retains the original power system architecture, and is equipped with the original engine control unit and signal output interface, which is connected to the communication bus;

[0050] In this embodiment, the tractor unit is equipped with an original engine control unit and a signal output interface conforming to the SAE J1939 standard. The output interface is an OBD-II circular 9-pin diagnostic socket or an AMP / Deutsch industrial connector, with 24V power supply capability and 125kbps~500kbps CAN communication capability. This interface is connected to the vehicle communication bus via a standard CAN harness (CAN_H and CAN_L).

[0051] The original powertrain architecture of the tractor unit includes the original engine control unit (including the engine controller and engine body), transmission, and vehicle controller. The original engine control unit, the main-trailer mechanical brake distribution controller, and the braking system controller all maintain their original control logic. The tractor unit's engine continues to output the required torque according to the vehicle controller's instructions, without altering the control strategy due to the presence of the trailer motor. The braking system also performs hydraulic braking control based on the brake pedal opening. The tractor unit's transmission maintains its original control logic, only providing the current gear status for assisting in calculating the vehicle's power distribution. Simultaneously, the main-trailer mechanical brake distribution controller coordinates the braking force distribution between the trailer and tractor unit by distributing the braking torque between the tractor unit's and trailer's mechanical brakes. The brake actuator on the electric trailer side can also perform regenerative braking control upon receiving a braking request, achieving a certain degree of brake energy recovery.

[0052] Electric drive trailer: equipped with a drive motor and energy storage device; wherein, the drive motor is installed at the trailer axle end, and the energy storage device is a lithium-ion battery pack, which is connected to the drive motor through a high-voltage wiring harness;

[0053] Electronic controller: Deployed on the electric drive trailer, it has a built-in STM32 series microprocessor and memory chip. The memory chip is pre-programmed with the offline interpolation table for motor control and stores the mapping relationship between vehicle speed, pedal opening and motor torque. The mapping relationship is generated by optimizing the vehicle's operating data and is matched with the power parameters of the tractor.

[0054] The electronic controller needs to be installed on the trailer, and its installation method is not limited. In this embodiment, the electronic controller is fixedly installed on the inner side of the longitudinal beam of the trailer frame or on the upper flange surface, using a 4-point stainless steel bolt connection, and equipped with rubber shock-absorbing pads.

[0055] Communication bus: Connects the tractor unit to the electronic controller, used to collect and transmit engine torque demand signals, engine speed signals, accelerator pedal opening signals, brake pedal opening signals, and gearbox gear signals. These signals are used to drive the tractor unit's own engine controller to output power, and are also sent synchronously to the electronic controller of the electric trailer via the bus as input for power coordination control of the trailer motor.

[0056] The electric trailer electronic controller, as an independent control unit, determines the target output torque and start / stop status of the trailer motor based on the received operating status signal of the tractor unit, using an electric trailer power control interpolation table. The interpolation table is calibrated during the design phase based on parameters such as engine torque requirements, speed, gear position, and pedal opening to achieve high-precision torque tracking output. During actual operation, the trailer controller quickly obtains the target torque command through a lookup table and sends this torque request to the trailer motor electronic controller. When the tractor unit accelerates, the trailer drive motor can provide positive drive torque for power compensation; when braking, the trailer drive motor can switch to energy regenerative braking mode to assist deceleration. This strategy helps reduce the load on the tractor unit and improves the vehicle's acceleration responsiveness and braking stability. Throughout the process, the trailer battery energy management system monitors the battery's state of charge (SOC), voltage, current, and other parameters in real time, dynamically adjusting the output or absorbable current capacity to prevent over-discharge or over-charge and ensure the safe operation of the drive motor. The drive motor then outputs the actual torque according to the instructions from the trailer motor electronic controller, achieving precise tracking of the tractor unit's torque request.

[0057] The electronic controller receives the engine's required torque T via the CAN bus. engine When the accelerator pedal opening is θ, the offline interpolation table is consulted based on the current vehicle speed v and the accelerator pedal opening θ, and the motor torque command T is output. motor The drive motor outputs a torque value that maintains a preset ratio range with the engine torque, and the drive motor executes the motor torque command T. motor Meanwhile, the energy storage device provides electrical energy.

[0058] Here, "torque ratio" refers to the ratio of the torque output from the trailer drive motor to the wheel ends to the torque output from the tractor engine to the wheel ends. To ensure the rationality of vehicle drive coordination and system stability, this ratio is calculated as "torque ratio = motor output wheel end torque / engine output wheel end torque". In this embodiment, the feasible range of this ratio is set as follows: the minimum value is 0 (i.e., the trailer electric drive does not output torque), and the maximum value does not exceed the ratio of the trailer's full load weight to the tractor's curb weight. In this embodiment, the maximum value is set to approximately 4.7. To ensure that this torque ratio always remains within the above-mentioned limits, the present invention adopts the following two-layer control mechanism:

[0059] 1) During the motor control strategy generation stage, the motor control interpolation table is generated by co-optimizing offline operating data and the vehicle target torque. Proportional boundary constraints are embedded in the process to ensure that the corresponding motor torque command always meets the above proportional range and will not exceed the design limit.

[0060] 2) During the actual operation of the electric drive system, the motor controller will also make a range judgment on the target output torque of the motor calculated in real time. If the corresponding ratio exceeds the set upper limit value, it will be automatically truncated to the maximum value to avoid the drive system from overloading.

[0061] In this embodiment, the communication bus is a CAN bus, but it can also be replaced by a FlexRay bus or an Ethernet protocol; the signal output interface of the tractor unit transmits the gearbox gear position signal and the brake pedal opening signal through the communication bus.

[0062] In this embodiment, the electric drive trailer is a single-axle or multi-axle electric drive axle configuration, and the power type of the tractor is one of diesel engine, natural gas engine, hydrogen fuel engine or other fuel engine.

[0063] In this embodiment, the electronic controller adopts a centralized or distributed topology; the energy storage device is a lithium-ion battery pack, which can be replaced by a supercapacitor pack.

[0064] Figure 2 The hardware connection relationship of the electric trailer torque following system in this embodiment is shown. The system includes a tractor unit and an electric drive trailer unit:

[0065] The tractor unit includes a load-bearing axle 1, an engine 2, a transmission 4, a drive axle 5, a tractor mechanical brake 6, a tractor vehicle controller 9, and a main-trailer mechanical brake distribution controller 10. The load-bearing axle 1 is a non-drive axle, bearing the front load of the tractor. The engine 2 is controlled by an engine controller 7, which connects to the transmission 4 via a clutch 3. The transmission 4 is controlled by a transmission controller 8 to shift gears, outputting power to the drive axle 5. The drive axle 5 is connected to the transmission 4, receiving power from the transmission 4 and driving the rear wheels of the tractor. The tractor mechanical brake 6 is connected to the drive axle 5, performing mechanical braking (including pneumatic braking). The tractor vehicle controller 9 is the main control core, used to collect signals such as engine torque / speed, accelerator / brake pedal opening, and transmission gear position, coordinating power distribution. The main-trailer mechanical brake distribution controller 10 controls the tractor mechanical brake 6 and the trailer mechanical brake via a pneumatic proportional control valve 11, thereby coordinating the distribution of mechanical braking force between the tractor and the trailer.

[0066] The electric drive trailer section includes an electric drive axle 17, a power battery 13, a motor electronic controller 16, a trailer power controller 15, a trailer drive motor 14, and a battery energy management system 12.

[0067] The electric drive axle 17 is the trailer drive axle, integrating the trailer drive motor—a permanent magnet synchronous motor 14; the power battery 13 is an energy storage device (lithium-ion battery or supercapacitor), connected to the trailer drive motor 14 via a high-voltage wiring harness; the motor electronic controller 16 controls the output torque of the trailer drive motor (permanent magnet synchronous motor) 14 or switches the regenerative braking mode. The trailer power controller 15 is the core controller, with a built-in offline interpolation table for motor control, executing a torque following strategy. The battery energy management system 12 monitors the status of the power battery 13 in real time and feeds back the available charging and discharging power to the trailer power controller 15 to ensure the safe operation of the trailer drive motor 14, thereby dynamically adjusting the charging and discharging capacity to prevent overcharging / over-discharging.

[0068] Under acceleration conditions, when the vehicle controller 9 transmits signals such as engine torque demand, speed, accelerator pedal opening, brake pedal opening, and gearbox gear to the trailer power controller 15, the trailer power controller 15 sends a motor torque command to the motor electronic controller 16 according to the offline interpolation table of motor control, thereby controlling the trailer drive motor (permanent magnet synchronous motor) 14 to output positive drive torque to compensate for the load of the tractor. The motor output torque is strictly limited within the preset ratio range of engine torque (0 to 4.7) to avoid excessive stress at the articulation point.

[0069] Under braking conditions, the braking signal triggers the trailer power controller 15 to switch the motor 14 to feedback mode, that is, to recover energy to the battery 13. At the same time, the main trailer mechanical brake distribution controller 10 coordinates the distribution of mechanical braking force.

[0070] Based on the electric trailer torque following control system proposed in the above embodiments, torque following control and automatic optimization of the electric trailer are performed, such as... Figure 3 As shown, the following steps are included in the following follow-up control strategy and automatic optimization method:

[0071] S1: Utilize vehicle sensors to collect vehicle speed and wheel-end torque signals under operating conditions, and set initial expected power consumption and error thresholds; simultaneously, set initial expected power consumption and error thresholds.

[0072] S2: During the initial calculation, a simplified mathematical vehicle dynamics model (numerical dynamics model) is used to generate a vehicle power demand dataset;

[0073] S3: Input the vehicle demand power dataset into the kernel density estimation program, set reasonable bandwidth parameters to filter out the influence of special operating conditions, and calculate the vehicle power density probability distribution feature dataset under different power and vehicle speed through the kernel density estimation algorithm.

[0074] S4: Input the above vehicle power density probability distribution feature dataset into the torque distribution control strategy optimization program. With the constraint that the engine torque and motor torque are in a positive proportion range, and the weighted total energy utilization efficiency as the optimization objective, combine the vehicle power density probability distribution feature dataset and generate the optimal motor control offline interpolation table for the pedal at different vehicle speeds through a recursive optimization algorithm (such as particle swarm optimization).

[0075] The evaluation index for the offline interpolation table of motor control is set as the total energy utilization efficiency of diesel and electricity under weighting, which is the integral of the product of the power probability distribution and the corresponding energy utilization efficiency. The weighting coefficient for gasoline is always set to 1, while the weighting coefficient for electricity is called the oil-electricity weighting factor, which is the variable for AOCP iterative optimization. In other words, through the torque distribution control strategy optimization program, the offline interpolation table of motor torque distribution for the electric trailer with the highest evaluation index and its corresponding oil-electricity weighting factor are output.

[0076] S5: Obtain real vehicle power demand dataset and actual energy consumption through actual vehicle testing, and execute the following automatic optimization and calibration process:

[0077] S5.1: Construct an energy consumption prediction model, input vehicle parameters (mass, drag coefficient, etc.) and operating conditions, and output the predicted power consumption;

[0078] S5.2: Use a genetic algorithm to optimize the adjustable parameter set (power efficiency, rolling resistance, etc.) of the energy consumption prediction model until the error between the predicted power consumption and the actual power consumption is less than the threshold (<5.5%), then fix the adjustable parameter set;

[0079] S5.3: Input the real vehicle power demand dataset into the kernel density estimation program and repeat steps S3-S4; then use the energy consumption prediction model that has been calibrated to calculate the predicted power consumption corresponding to the optimized torque following strategy; determine whether the predicted power consumption reaches the expected power consumption. If it does, output the torque distribution interpolation table, i.e., the optimal torque difference table; if the error between the predicted power consumption and the expected power consumption is greater than the set threshold, record the current power consumption and the oil-electric weight factor, and use Bayesian optimization to adjust the oil-electric weight factor α, and update the motor control offline interpolation table in combination with the calibrated energy consumption prediction model.

[0080] The Bayesian optimization is performed as follows: a Gaussian process regression model is constructed using Bayesian optimization to fit the functional relationship between the oil-electricity weighting factor and the estimated power consumption; then, the next sampling point for the oil-electricity weighting factor is selected by maximizing the obtained function. This method allows the desired solution to be obtained with as few iterations as possible. Finally, step S4 is repeated to obtain the updated offline interpolation table for motor torque distribution.

[0081] S5.4: Repeat step S5.3 until the estimated power consumption reaches the expected power consumption, output the final motor control offline interpolation table, that is, output the corresponding optimal motor torque distribution offline interpolation table, and record its oil-electric weight factor.

[0082] The above are merely preferred embodiments of this utility model and do not constitute any limitation on this utility model. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and contents disclosed in this utility model without departing from the scope of the technical solutions of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A torque following control system for an electric trailer, characterized in that, include: Tractor: Retain the original engine control unit and signal output interface; Electric trailer: equipped with a drive motor and energy storage device; Electronic controller: Deployed on the electric drive trailer, with built-in storage of offline interpolation tables for motor control; Communication bus: connects the tractor vehicle and the electronic controller, and is used to transmit engine torque demand signal, engine speed signal, accelerator pedal opening signal, brake pedal opening signal and gearbox gear signal; The electronic controller is configured as follows: 1) Based on the received engine torque demand signal, engine speed signal, accelerator pedal opening signal, brake pedal opening signal and gearbox gear signal, query the offline interpolation table of motor control to generate motor torque command; 2) Control the output torque value of the drive motor to maintain a preset ratio range with the engine torque.

2. The electric trailer torque following control system according to claim 1, characterized in that, The communication bus is a CAN bus, FlexRay bus, or Ethernet protocol; the signal output interface transmits the gearbox gear position signal and brake pedal opening signal through the communication bus.

3. The electric trailer torque following control system according to claim 1, characterized in that, The electric drive trailer is a single-axle or multi-axle electric drive axle configuration, and the tractor is powered by a diesel engine, a natural gas engine, or a hydrogen fuel cell engine.

4. The electric trailer torque following control system according to claim 1, characterized in that, The electronic controller adopts a centralized or distributed topology; the energy storage device is a lithium-ion battery pack or a supercapacitor pack.

5. The electric trailer torque following control system according to claim 1, characterized in that, The offline interpolation table for motor control stores the mapping relationship between vehicle speed, accelerator pedal opening, and motor torque value; the mapping relationship is generated through optimization of vehicle operating data and is matched with the power parameters of the tractor.

Images