Flatbed wheel end demand torque and power calculation method, device, equipment and medium

Abstract

The present application belongs to the technical field of demand torque calculation of unmanned vehicle wheel end, and specifically provides a flat car wheel end demand torque and power calculation method, device, equipment and medium. The method comprises the following steps: calculating the wheel end demand torque of the manual driving mode based on the corresponding limit torque, throttle opening, electric drive axle ratio under the front and rear axle motor speed, combined with the actual vehicle speed and accelerator pedal opening; calculating the wheel end demand torque of the unmanned driving mode based on the map information and driving road conditions; performing sliding window filtering processing on the calculated wheel end demand torque value; calculating the wheel end demand power in the manual driving mode by combining the filtered wheel end demand torque of the manual driving mode with the actual vehicle speed; and calculating the wheel end demand power in the unmanned driving mode by combining the filtered wheel end demand torque of the unmanned driving mode with the tire speed and forward and reverse coefficient. The driving stability and safety of the pure electric flat car are improved.

Description

Technical Field

[0001] This invention relates to the field of wheel-end torque demand calculation technology for unmanned vehicles, specifically to a method, device, equipment, and medium for calculating wheel-end torque and power demand of a flatbed vehicle. Background Technology

[0002] With the growth of global trade and the expansion of port operations, port logistics and transportation have become more important and complex. To improve the efficiency and safety of port cargo transportation, the adoption of fully electric, driverless flatbed trucks has emerged as a promising solution. These flatbed trucks can autonomously navigate within the port, carrying goods from the dock to warehouses or other destinations, thereby reducing labor costs and time consumption.

[0003] Traditional port cargo transportation typically relies on manually driven diesel or gasoline vehicles, a method that presents several challenges and limitations. First, manual driving requires hiring drivers, which is costly and inefficient. Second, exhaust emissions from fuel-powered vehicles pollute the environment. Furthermore, ports are often busy and congested environments, requiring precise driving and navigation skills to avoid accidents.

[0004] A fully electric, driverless flatbed truck for ports can solve the aforementioned problems. This vehicle will use an electric drive system instead of a traditional combustion engine, achieving zero-emission operation. The fully electric flatbed truck reduces the risk of human error and accidents. Through this innovative solution, port transportation will become more efficient, environmentally friendly, and safe. How to calculate the torque and power requirements at the wheel ends of the fully electric, driverless flatbed truck is the technical problem this application aims to solve. Summary of the Invention

[0005] To address the problem of calculating the required torque and power at the wheel end of a pure electric unmanned flatbed truck, this invention provides a method, apparatus, equipment, and medium for calculating the required torque and power at the wheel end of a flatbed truck.

[0006] In a first aspect, the present invention provides a method for calculating the required torque and power at the wheel end of a flatbed truck, comprising the following steps:

[0007] The wheel-end torque required in manual driving mode is calculated based on the limiting torque, throttle opening, and electric drive axle speed ratio corresponding to the front and rear axle motor speeds, combined with the actual vehicle speed and accelerator pedal opening.

[0008] Calculate the wheel-end torque requirement for autonomous driving mode based on map information and road conditions;

[0009] The calculated wheel-end torque demand value is then subjected to sliding window filtering.

[0010] The wheel-end demand torque in the filtered manual driving mode is combined with the actual vehicle speed to calculate the wheel-end demand power in the manual driving mode.

[0011] The wheel-end power demand of the autonomous driving mode is calculated by combining the filtered wheel-end torque demand with the tire speed and forward / reverse coefficients.

[0012] As a further limitation of the technical solution of the present invention, the step of calculating the wheel-end torque requirement in manual driving mode based on the limiting torque corresponding to the front and rear axle motor speeds, throttle opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening includes:

[0013] The required torque at the reference wheel end is calculated based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal throttle opening, and the electric drive axle speed ratio.

[0014] A model is established based on the actual vehicle speed and throttle opening to calculate the undetermined wheel-end torque related to vehicle speed;

[0015] Calculate the difference between the reference wheel end torque requirement and the undetermined wheel end torque requirement;

[0016] The recursive least squares algorithm is used to adjust the parameters of the model based on the magnitude and direction of the difference, so as to obtain the wheel-end torque requirement in the manual driving mode.

[0017] As a further limitation of the technical solution of the present invention, the step of calculating the required torque at the reference wheel end based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal throttle opening, and the electric drive axle speed ratio includes:

[0018] The reference torque required at the front axle wheel end is obtained by multiplying the peak torque corresponding to the current speed of the front axle main motor by the accelerator pedal opening.

[0019] The reference torque required at the rear axle wheel end is obtained by multiplying the peak torque corresponding to the current speed of the rear axle main motor by the accelerator pedal opening.

[0020] The reference wheel-end torque is obtained by multiplying the front axle wheel-end reference torque and the rear axle wheel-end reference torque by the electric drive axle speed ratio and then summing them.

[0021] As a further limitation of the technical solution of the present invention, the step of calculating the wheel-end torque requirement in autonomous driving mode based on map information and road conditions includes:

[0022] Calculate the percentage of torque required based on map information and road conditions;

[0023] The peak torque limit is obtained by summing the peak torque corresponding to the current speed of the front axle main motor and the peak torque corresponding to the current speed of the rear axle main motor.

[0024] The wheel-end torque requirement in autonomous driving mode is obtained by multiplying the peak torque limit, the percentage of required torque, and the electric drive axle speed ratio.

[0025] The system fully considers both manual and autonomous driving modes. In manual driving mode, factors such as the limiting torque corresponding to the front and rear axle motor speeds, accelerator pedal opening, and speed ratio are taken into account to calculate the reference wheel-end torque requirement. This calculation is then corrected and updated based on the model established by the actual vehicle speed and accelerator pedal opening to obtain a more reasonable wheel-end torque requirement. In autonomous driving mode, the system automatically calculates the percentage of torque requirement based on map information and road conditions in the VCU controller. The wheel-end torque requirement is then obtained from the peak torque limit. The two modes are integrated and output to obtain the wheel-end torque requirement value, thereby meeting the various limiting requirements of the entire power control system.

[0026] As a further limitation of the technical solution of the present invention, the step of performing sliding window filtering on the calculated wheel end torque value includes:

[0027] Define the size of the sliding time window;

[0028] Obtain the wheel-end torque demand value within the sliding time window and process the obtained wheel-end torque demand value; specifically, this includes: replacing the wheel-end torque demand value that is greater than the torque limit with the torque limit, and performing zero-crossing processing on the wheel-end torque demand value when the motor torque changes from negative torque or zero torque to positive torque, or from positive torque or zero torque to negative torque;

[0029] After processing, the average torque within the sliding time window is calculated and recorded as the smoothed wheel end demand torque value, which is the wheel end demand torque value after filtering.

[0030] If not, proceed as follows: Calculate the average torque within the sliding time window and record it as the smoothed wheel end demand torque value, which is the value of the wheel end demand torque after filtering.

[0031] To make the required torque value smoother and avoid its drastic changes, filtering is performed, which improves the driving stability and safety of the pure electric flatbed truck.

[0032] As a further limitation of the technical solution of the present invention, the step of calculating the wheel-end power demand in the manual driving mode by combining the filtered wheel-end demand torque with the actual vehicle speed includes:

[0033] The wheel-end torque demand T of the filtered manual driving mode 轮端 Calculate the required power W at the reference wheel end based on the actual vehicle speed. 参考 =V 车速 *T 轮端 *1000 / (9550*60*2*3.14*R 轮胎 );

[0034] Calculate the wheel-end traction force based on the actual vehicle speed and weight;

[0035] A model is established based on the wheel-end traction force and actual vehicle speed to calculate the required power at the undetermined wheel-end;

[0036] Calculate the difference between the reference wheel-end power demand and the undetermined wheel-end power demand;

[0037] The recursive least squares algorithm is used to adjust the model parameters based on the magnitude and direction of the difference to obtain the wheel-end power demand in the manual driving mode.

[0038] As a further limitation of the technical solution of the present invention, the step of calculating the wheel-end power demand of the autonomous driving mode by combining the wheel-end demand torque of the filtered autonomous driving mode with the tire speed and forward / reverse coefficients includes:

[0039] The wheel-end power requirement of the autonomous driving mode is obtained by multiplying the wheel-end torque requirement, tire speed, and forward / reverse coefficients after filtering and dividing by a set constant.

[0040] Both manual and autonomous driving modes were considered. In manual driving mode, the reference wheel-end power demand was calculated from the updated wheel-end torque demand and the actual vehicle speed. Then, based on the model established by the actual vehicle speed and traction power, the undetermined wheel-end power demand was calculated. After model correction and updating, a suitable wheel-end power demand value was obtained, which met the motor power limit. In autonomous driving mode, the wheel-end power demand was calculated from the required torque obtained from the torque percentage and the wheel-end speed. The two modes were integrated to output the required power, which is more in line with the actual driving power demand and achieves energy-saving and efficient operation.

[0041] Secondly, the technical solution of the present invention also provides a flatbed wheel end demand torque and power calculation device, including a manual mode demand torque calculation module, an autonomous driving mode demand torque calculation module, a filtering module, a manual mode demand power calculation module and an autonomous driving demand power calculation module.

[0042] The manual mode torque demand calculation module is used to calculate the wheel end torque demand in manual driving mode based on the limiting torque corresponding to the front and rear axle motor speeds, throttle opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening.

[0043] The autonomous driving mode torque demand calculation module is used to calculate the wheel-end torque demand in autonomous driving mode based on map information and road conditions.

[0044] The filtering module is used to perform sliding window filtering on the calculated wheel end torque demand value;

[0045] The manual driving mode power demand calculation module is used to calculate the wheel-end power demand in the manual driving mode by combining the filtered wheel-end torque demand with the actual vehicle speed.

[0046] The autonomous driving power demand calculation module is used to calculate the wheel-end power demand of the autonomous driving mode by combining the filtered wheel-end torque demand with the tire speed and forward / reverse coefficients.

[0047] As a further limitation of the technical solution of the present invention, the manual mode required torque calculation module includes a reference torque calculation unit, a to-be-determined torque calculation unit, and a torque calculation adjustment processing unit.

[0048] The reference torque calculation unit is used to calculate the required torque at the reference wheel end based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal throttle opening, and the electric drive axle speed ratio.

[0049] The undetermined torque calculation unit is used to calculate the undetermined wheel end torque related to the vehicle speed by establishing a model based on the actual vehicle speed and throttle opening.

[0050] The torque calculation and adjustment processing unit is used to calculate the difference between the reference wheel-end demand torque and the undetermined wheel-end demand torque, and uses a recursive least squares algorithm to adjust the model parameters according to the magnitude and direction of the difference to obtain the wheel-end demand torque in the manual driving mode.

[0051] As a further limitation of the technical solution of the present invention, the reference torque calculation unit is specifically used to multiply the peak torque corresponding to the current speed of the front axle main motor by the accelerator pedal throttle opening to obtain the reference required torque at the front axle wheel end; multiply the peak torque corresponding to the current speed of the rear axle main motor by the accelerator pedal throttle opening to obtain the reference required torque at the rear axle wheel end; and sum the reference required torque at the front axle wheel end and the reference required torque at the rear axle wheel end by the electric drive axle speed ratio respectively to obtain the reference required torque at the wheel end.

[0052] As a further limitation of the technical solution of the present invention, the autonomous driving mode torque demand calculation module includes a torque percentage calculation unit, a torque limit calculation unit, and a demand torque calculation unit.

[0053] The torque percentage calculation unit is used to calculate the required torque percentage based on map information and driving conditions.

[0054] The torque limit calculation unit is used to sum the peak torque corresponding to the current speed of the front axle main motor and the peak torque corresponding to the current speed of the rear axle main motor to obtain the peak torque limit.

[0055] The demand torque calculation unit is used to calculate the product of the peak torque limit, the demand torque percentage, and the electric drive axle speed ratio to obtain the wheel-end demand torque in autonomous driving mode.

[0056] As a further limitation of the technical solution of the present invention, the filtering processing module includes a time window definition unit, a torque anomaly processing unit, and a filtering processing unit;

[0057] The time window definition unit is used to define the size of the sliding time window;

[0058] The torque anomaly processing unit is used to obtain the wheel end demand torque value within the sliding time window, replace the wheel end demand torque value that is greater than the torque limit with the torque limit; and perform zero-crossing processing when there is a zero-crossing point.

[0059] The filtering unit is used to calculate the average torque within the sliding time window and record it as the smoothed wheel end demand torque value, that is, the wheel end demand torque value after filtering.

[0060] As a further limitation of the technical solution of the present invention, the manual mode power demand calculation module includes a reference power calculation unit, a traction force calculation unit, a power calculation unit to be determined, and a power calculation adjustment processing unit.

[0061] The reference power calculation unit is used to calculate the wheel-end torque T required in the filtered manual driving mode. 轮端 Calculate the required power W at the reference wheel end based on the actual vehicle speed. 参考 =V 车速 *T 轮端 *1000 / (9550*60*2*3.14*R 轮胎 );

[0062] The traction calculation unit is used to calculate the wheel-end traction force based on the actual vehicle speed and weight.

[0063] The undetermined power calculation unit is used to calculate the undetermined wheel end power demand based on the wheel end traction force and actual vehicle speed by establishing a model.

[0064] The power calculation and adjustment processing unit is used to calculate the difference between the reference wheel-end demand power and the undetermined wheel-end demand power; the recursive least squares algorithm is used to adjust the parameters of the model according to the magnitude and direction of the difference to obtain the wheel-end demand power in the manual driving mode.

[0065] As a further limitation of the technical solution of the present invention, the autonomous driving power demand calculation module is specifically used to multiply the wheel end demand torque, tire speed and forward / backward coefficient of the filtered autonomous driving mode by a set constant to obtain the wheel end demand power of the autonomous driving mode.

[0066] Thirdly, the present invention provides an electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor; the memory storing computer program instructions executable by the at least one processor, the computer program instructions being executed by the at least one processor to enable the at least one processor to perform the flatbed wheel end demand torque and power calculation method as described in the first aspect.

[0067] Fourthly, the present invention also provides a non-transitory computer-readable storage medium that stores computer instructions that cause the computer to execute the flatbed wheel end demand torque and power calculation method as described in the first aspect.

[0068] As can be seen from the above technical solutions, the present invention has the following advantages:

[0069] Both manual and autonomous driving modes are fully considered. For manual driving mode, the reference torque demand value is calculated based on factors such as motor speed, throttle opening and speed ratio. The undetermined wheel-end torque demand value is calculated based on a model established according to the actual vehicle speed and accelerator pedal opening. The torque difference is calculated using a recursive least squares algorithm to update the model parameters and obtain the final wheel-end torque demand value. For autonomous driving mode, the percentage of torque demand is automatically calculated from map information and road conditions in the VCU controller. The wheel-end torque demand value is obtained from the peak torque limit. The final wheel-end torque demand value obtained by the above method is more reasonable.

[0070] 2. This makes the torque demand value at the wheel end smoother, avoiding drastic changes and improving the driving stability and safety of the pure electric flatbed vehicle.

[0071] 3. Both manual and unmanned driving modes were considered, including motor torque limits and motor power, making the calculated wheel-end torque and power requirements more reasonable, resulting in smoother driving, improved motor operation stability and energy utilization, and better meeting the actual driving power requirements, thus achieving energy-saving and efficient operation.

[0072] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects.

[0073] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0074] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0075] Figure 1 This is a schematic flowchart of a method according to an embodiment of the present invention.

[0076] Figure 2 This is a schematic diagram of the sliding window filtering process in an embodiment of the present invention.

[0077] Figure 3 This is a schematic diagram illustrating the process of calculating the wheel-end power demand in manual driving mode in an embodiment of the present invention.

[0078] Figure 4 This is a schematic block diagram of an apparatus according to an embodiment of the present invention. Detailed Implementation

[0079] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0080] like Figure 1 As shown, this embodiment of the invention provides a method for calculating the required torque and power at the wheel end of a flatbed truck, including the following steps:

[0081] Step 1: Calculate the wheel-end torque required in manual driving mode based on the limiting torque, throttle opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening at the corresponding front and rear axle motor speeds.

[0082] Step 2: Calculate the wheel-end torque requirement for autonomous driving mode based on map information and road conditions;

[0083] Step 3: Perform sliding window filtering on the calculated wheel end torque demand value;

[0084] Step 4: Combine the filtered wheel-end torque demand in the manual driving mode with the actual vehicle speed to calculate the wheel-end power demand in the manual driving mode;

[0085] Step 5: Calculate the wheel-end power demand of the autonomous driving mode by combining the filtered wheel-end torque demand with the tire speed and forward / reverse coefficients.

[0086] In some embodiments, the step of calculating the wheel-end torque requirement in manual driving mode based on the limiting torque corresponding to the front and rear axle motor speeds, throttle opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening includes:

[0087] Step 11: Calculate the required torque at the reference wheel end based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal throttle opening, and the electric drive axle speed ratio;

[0088] This step specifically includes:

[0089] The reference torque T at the front axle wheel end is obtained by multiplying the peak torque corresponding to the current speed of the front axle main motor by the accelerator pedal opening. 前桥 = Peak torque corresponding to the current speed of the front axle main motor * accelerator pedal opening;

[0090] The reference torque T at the rear axle wheel end is obtained by multiplying the peak torque corresponding to the current speed of the rear axle main motor by the accelerator pedal opening. 后桥 = Peak torque corresponding to the current speed of the rear axle main motor * accelerator pedal opening;

[0091] The reference wheel-end torque T is obtained by multiplying the front axle wheel-end reference torque and the rear axle wheel-end reference torque by the electric drive axle speed ratio and then summing them. 参考 =T 前桥 *K 速比 +T 后桥 *K 速比 ;K 速比 This represents the speed ratio of the electric drive bridge.

[0092] Step 12: Calculate the required wheel-end torque related to vehicle speed by establishing a model based on the actual vehicle speed and throttle opening;

[0093] Step 13: Calculate the difference between the reference wheel-end required torque and the undetermined wheel-end required torque; use a recursive least squares algorithm to adjust the model parameters according to the magnitude and direction of the difference to obtain the wheel-end required torque in the manual driving mode.

[0094] A model built from actual vehicle speed and accelerator pedal opening (this model is an observation model trained and simulated based on a large amount of data such as vehicle speed, accelerator pedal opening, and corresponding wheel-end torque demand values; it is equivalent to a black box system, requiring only input vehicle speed and accelerator pedal opening signals to obtain the wheel-end torque demand value) is used to calculate a speed-related undetermined torque demand value T. 待定 The difference between the reference required torque and the undetermined required torque value is calculated. The RLS (Recursive Least Squares) algorithm is used to update the model parameters, and the model gain and weight parameters are adjusted based on the magnitude and direction of the difference. Initially, the model parameters are assigned empirical values, and the oblique variance matrix is ​​initialized as a large diagonal matrix to allow for larger parameter updates. Subsequent updates are based on the input and output data. The gain vector is multiplied by the difference value and added to the previous undetermined required torque value to obtain a new wheel-end required torque value. This iterative update process continues until the final wheel-end required torque value T is obtained. 轮端 The specific formula is as follows:

[0095] Let the input signal x(t) and output signal T of the model be... 待定 (t). The crane operator's input signal x(t) includes the vehicle speed V and the throttle opening signal IO;

[0096] Calculate the current output T 待定 (t)=w(t-1)^T*x(t).

[0097] Calculate the error between the two, e(t) = T 参考 (t)-T 待定 (t).

[0098] Calculate the gain vector k(t) = P(t-1)*x(t) / (lambda+x(t)^T*P(t-1)*x(t)), where lambda is a small positive number used to control numerical stability.

[0099] Update the parameter vector w(t) = w(t-1) + k(t) * e(t).

[0100] For a black-box system, the input is the observation matrix X, and the output value T is obtained. The unknown state parameter vector is W. This is obtained by adding the difference e(t) between the estimated output and the reference output to the K gain vector to obtain the current W(t) at the (t-1)th optimal estimate W.

[0101] Update the covariance matrix P(t) = (1 / lambda) * [P(t-1) - k(t) * x(t) * P(t-1)].

[0102] After a series of formula derivations, the recursive relationships of P(t) and P(t-1) are obtained by simplification. The covariance matrix P gradually decreases as each input observation of X is substituted.

[0103] The final wheel-end torque T can be obtained from the above formula. 轮端 .

[0104] T 轮端 = w(t)^T*x(t);

[0105] T 轮端 It is a specific value. The parameter matrix w(t) is finally estimated, and then multiplied by the input matrix x(t) to obtain the value.

[0106] In some embodiments, the step of calculating the wheel-end torque requirement in autonomous driving mode based on map information and road conditions includes:

[0107] Step 21: Calculate the required torque percentage based on map information and road conditions;

[0108] This comes from the ADCU drive controller and is sent directly to the vehicle controller (VCU) via CAN message. It is a torque percentage value that can be used directly.

[0109] Step 22: Sum the peak torque corresponding to the current speed of the front axle main motor and the peak torque corresponding to the current speed of the rear axle main motor to obtain the peak torque limit;

[0110] Step 23: Calculate the product of the peak torque limit, the required torque percentage, and the electric drive axle speed ratio to obtain the wheel-end torque requirement in autonomous driving mode.

[0111] In autonomous driving mode, the required torque at the wheel ends is calculated. First, the required torque percentage L is automatically calculated from the map information and driving conditions in the VCU controller. 扭矩 ;

[0112] T 峰值 =T 前桥峰值 +T 后桥峰值 ;

[0113] T 轮端 =T 峰值 *L 扭矩 *K 速比 ;

[0114] When in different driving modes, the required torque is calculated using the method of the current mode to obtain the required torque at the wheel end.

[0115] In some embodiments, such as Figure 2 As shown, the steps for performing sliding window filtering on the calculated wheel-end torque demand value include:

[0116] Step 31: Define the size of the sliding time window;

[0117] Step 32: Obtain the value of the wheel end required torque within the sliding time window and process the obtained wheel end required torque value; specifically, this includes: replacing the wheel end required torque value that is greater than the torque limit with the torque limit, and performing zero-crossing processing on the wheel end required torque value when the motor torque changes from negative torque or zero torque to positive torque, or from positive torque or zero torque to negative torque;

[0118] Step 33: After processing, calculate the average torque within the sliding time window and record it as the smoothed wheel end demand torque value, which is the wheel end demand torque value after filtering.

[0119] Based on the principle of sliding window averaging filtering, an appropriate sliding time window is selected to calculate the average torque over a period of time, which is then used as the filtered value to reduce the impact of sudden changes in the required torque value on the system. This method can reduce instantaneous changes in torque. When the motor torque changes from negative or zero torque to positive torque, or from positive or zero torque to negative torque, the change in torque direction will cause a change in the gear contact surface due to the clearance in the gear meshing of the transmission system. Near the zero-crossing torque range, a large torque can easily cause a shock. To mitigate this situation, a sliding window filtering method can be used to allow the torque to transition slowly near the zero-crossing point.

[0120] In addition, the motor temperature, oil temperature and motor torque limit coefficient must be considered to ensure that the torque required at the wheel end does not exceed the system torque capacity at the current vehicle speed.

[0121] The general steps are as follows: First, define the sliding window size as N, and initialize the sliding window with the first N output data points;

[0122] For each time step t, starting from the (N+1)th data point, a sliding window average filtering process is performed:

[0123] Calculate the output T at the current time t 轮端 (t) is updated by averaging the data within the window by adding the output from the previous time step to the current time step.

[0124] T 平滑轮端 (t)=(T 轮端 (t)+T 轮端 (t-1)+...+T 轮端 (t-N+1)) / N

[0125] Finally, the filtered and smoothed wheel-end torque value T is obtained through the above operations. 平滑轮端 .

[0126] In some embodiments, such as Figure 3 As shown, the steps for calculating the wheel-end power demand in manual driving mode by combining the filtered wheel-end torque demand with the actual vehicle speed include:

[0127] Step 41: Calculate the wheel-end torque demand T of the filtered manual driving mode. 轮端 Calculate the required power W at the reference wheel end based on the actual vehicle speed. 参考 =V 车速 *T 轮端 *1000 / (9550*60*2*3.14*R 轮胎 );

[0128] Step 42: Calculate the wheel-end traction force based on the actual vehicle speed and weight;

[0129] F 阻力 (t)=0.11*V 车速 (t)^2+15.58*V 车速 (t)+1154

[0130] G(s) = K 增益 *(1-2 / T 采样 *s) / (T 采样 *s)

[0131] In the formula, s is the complex frequency in the continuous time domain, and T 采样 It is the sampling time interval.

[0132] F 推力 (t)=V 车速 (t)*G(s)*M 车重

[0133] F 牵引力 (t)=(F 阻力 (t)+F 推力 (t)) / 1000

[0134] Step 43: Calculate the required power W at the undetermined wheel end based on the wheel-end traction force and actual vehicle speed. 待定 =V 车速 (t)*F 牵引力 (t);

[0135] Step 44: Calculate the difference between the reference wheel-end power demand and the undetermined wheel-end power demand; use the recursive least squares algorithm to adjust the model parameters according to the magnitude and direction of the difference to obtain the wheel-end power demand in the manual driving mode.

[0136] Determine the undetermined power requirement W 待定 In comparison, W 参考 It contains constraints on torque limits and motor power, for W 待定 For updating and correction, a recursive least squares algorithm is used to calculate the difference between the reference wheel-end demand power and the undetermined wheel-end demand power to update the model parameters. Initially, the model parameters are assigned empirical values, and the oblique variance matrix is ​​initialized as a large diagonal matrix to allow for larger parameter updates. Subsequent updates are based on the input and output data, iteratively updating the parameters. The model gain and weight parameters are adjusted according to the magnitude and direction of the difference to obtain the wheel-end demand power. This iterative update process continues until the wheel-end demand power W that satisfies the constraints is finally obtained. 轮端 The specific formula is as follows:

[0137] Assume the input signal x(t) and output signal W of the model are... 待定 (t).

[0138] Calculate the current output W 待定 (t)=w(t-1)^T*x(t).

[0139] Calculate the error between the two, e(t) = W 参考 (t)-W 待定 (t).

[0140] Calculate the gain vector k(t) = P(t-1)*x(t) / (lambda+x(t)^T*P(t-1)*x(t)), where lambda is a small positive number used to control numerical stability.

[0141] Update the parameter vector w(t) = w(t-1) + k(t) * e(t).

[0142] Update the covariance matrix P(t) = (1 / lambda) * [P(t-1) - k(t) * x(t) * P(t-1)].

[0143] The final wheel-end power requirement W can be obtained from the above formula. 轮端 :

[0144] W 轮端 = w(t)^T*x(t).

[0145] The input X(t) includes the wheel-end traction force F and the actual vehicle speed V, and the output is W. 待定 (t), estimate the state parameter vector W(t) of the entire black-box system. The current output is obtained by multiplying the previously estimated parameter vector W(t-1) by the input value x(t), and calculating the difference e(t) between the reference power and the output power to be determined. For the parameter vector W(t), this is the observation matrix with input X for the black-box system, obtaining W 待定 The output power, where the unknown state parameter vector is W, is obtained by multiplying the (t-1)th optimal estimate W(t-1) by the difference e(t) between the estimated output and the reference output by the K gain vector. For the covariance matrix, the recursive relationship between P(t) and P(t-1) is derived and simplified through formula derivation. The covariance matrix P gradually decreases with each input observation of X. Finally, the wheel-end power demand W is obtained by multiplying the estimated optimal parameter vector by the input observation vectors Ftraction and Vvehicle. 轮端 .

[0146] Accordingly, the steps for calculating the wheel-end power demand of the autonomous driving mode by combining the filtered wheel-end torque demand with tire speed and forward / reverse coefficients include:

[0147] The wheel-end power demand W of the autonomous driving mode is obtained by multiplying the filtered wheel-end torque demand, tire speed, and forward / reverse coefficients, and then dividing by a set constant. 轮端 =T 轮端 *Ns 转速 *K 驱动系数 / 9550.

[0148] This calculation method fully considers both manual and autonomous driving modes. For manual driving mode, the reference torque demand value is calculated based on factors such as motor speed, throttle opening, and speed ratio. The undetermined torque demand value is calculated based on a model established according to the actual vehicle speed and accelerator pedal opening. The torque difference value is calculated using a recursive least squares algorithm to update the model parameters and obtain the final wheel-end torque demand value. For autonomous driving mode, the percentage of torque demand is automatically calculated based on map information and road conditions in the VCU controller. The wheel-end torque demand value is obtained from the peak torque limit. First, both manual and autonomous driving modes are considered simultaneously to ensure that the torque value obtained after model update is more reasonable and meets the torque limit requirements. Second, a sliding window filter is applied to the required torque value to avoid drastic changes and ensure smooth driving. Third, similarly, when calculating the wheel-end power requirement, both modes are considered: in manual driving mode, the reference wheel-end power requirement is calculated from the updated wheel-end torque requirement and the actual vehicle speed; then, based on the model established by the actual vehicle speed and traction power, the undetermined wheel-end power requirement is calculated; after model correction and update, a suitable wheel-end power requirement value is obtained, meeting the motor power limit. In autonomous driving mode, the wheel-end power requirement is calculated from the required torque obtained from the torque percentage and the wheel-end speed. Integrating the two modes to output the required power better matches the actual driving power requirements, achieving energy-saving and efficient operation.

[0149] like Figure 4 As shown, the present invention also provides a device for calculating the required torque and power at the wheel end of a flatbed truck, including a manual mode required torque calculation module, an autonomous driving mode required torque calculation module, a filtering module, a manual mode required power calculation module, and an autonomous driving required power calculation module.

[0150] The manual mode torque demand calculation module is used to calculate the wheel end torque demand in manual driving mode based on the limiting torque corresponding to the front and rear axle motor speeds, throttle opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening.

[0151] The autonomous driving mode torque demand calculation module is used to calculate the wheel-end torque demand in autonomous driving mode based on map information and road conditions.

[0152] The filtering module is used to perform sliding window filtering on the calculated wheel end torque demand value;

[0153] The manual driving mode power demand calculation module is used to calculate the wheel-end power demand in the manual driving mode by combining the filtered wheel-end torque demand with the actual vehicle speed.

[0154] The autonomous driving power demand calculation module is used to calculate the wheel-end power demand of the autonomous driving mode by combining the filtered wheel-end torque demand with the tire speed and forward / reverse coefficients.

[0155] In some embodiments, the manual mode required torque calculation module includes a reference torque calculation unit, a pending torque calculation unit, and a torque calculation adjustment processing unit.

[0156] The reference torque calculation unit is used to calculate the required torque at the reference wheel end based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal throttle opening, and the electric drive axle speed ratio.

[0157] The undetermined torque calculation unit is used to calculate the undetermined wheel end torque related to the vehicle speed by establishing a model based on the actual vehicle speed and throttle opening.

[0158] The torque calculation and adjustment processing unit is used to calculate the difference between the reference wheel-end demand torque and the undetermined wheel-end demand torque, and uses a recursive least squares algorithm to adjust the model parameters according to the magnitude and direction of the difference to obtain the wheel-end demand torque in the manual driving mode.

[0159] In some embodiments, the reference torque calculation unit is specifically used to multiply the peak torque corresponding to the current speed of the front axle main motor by the accelerator pedal throttle opening to obtain the reference required torque at the front axle wheel end; multiply the peak torque corresponding to the current speed of the rear axle main motor by the accelerator pedal throttle opening to obtain the reference required torque at the rear axle wheel end; and sum the reference required torque at the front axle wheel end and the reference required torque at the rear axle wheel end by the electric drive axle speed ratio respectively to obtain the reference required torque at the wheel end.

[0160] In some embodiments, the autonomous driving mode torque demand calculation module includes a torque percentage calculation unit, a torque limit calculation unit, and a demand torque calculation unit.

[0161] The torque percentage calculation unit is used to calculate the required torque percentage based on map information and driving conditions.

[0162] The torque limit calculation unit is used to sum the peak torque corresponding to the current speed of the front axle main motor and the peak torque corresponding to the current speed of the rear axle main motor to obtain the peak torque limit.

[0163] The demand torque calculation unit is used to calculate the product of the peak torque limit, the demand torque percentage, and the electric drive axle speed ratio to obtain the wheel-end demand torque in autonomous driving mode.

[0164] In some embodiments, the filtering module includes a time window definition unit, a torque anomaly processing unit, and a filtering unit;

[0165] The time window definition unit is used to define the size of the sliding time window;

[0166] The torque anomaly processing unit is used to obtain the value of the wheel end demand torque within the sliding time window; replace the wheel end demand torque value that is greater than the torque limit with the torque limit; and perform zero-crossing processing when there is a zero-crossing point.

[0167] The filtering unit is used to calculate the average torque within the sliding time window and record it as the smoothed wheel end demand torque value, that is, the wheel end demand torque value after filtering.

[0168] In some embodiments, the manual mode power demand calculation module includes a reference power calculation unit, a traction force calculation unit, a power calculation unit to be determined, and a power calculation adjustment processing unit.

[0169] The reference power calculation unit is used to calculate the wheel-end torque T required in the filtered manual driving mode. 轮端 Calculate the required power W at the reference wheel end based on the actual vehicle speed. 参考 =V 车速 *T 轮端 *1000 / (9550*60*2*3.14*R 轮胎 );

[0170] The traction calculation unit is used to calculate the wheel-end traction force based on the actual vehicle speed and weight.

[0171] The undetermined power calculation unit is used to calculate the undetermined wheel end power demand based on the wheel end traction force and actual vehicle speed by establishing a model.

[0172] The power calculation and adjustment processing unit is used to calculate the difference between the reference wheel-end demand power and the undetermined wheel-end demand power; the recursive least squares algorithm is used to adjust the parameters of the model according to the magnitude and direction of the difference to obtain the wheel-end demand power in the manual driving mode.

[0173] In some embodiments, the autonomous driving power demand calculation module is specifically used to multiply the wheel-end demand torque, tire speed, and forward / reverse coefficient of the filtered autonomous driving mode by a set constant to obtain the wheel-end demand power of the autonomous driving mode.

[0174] This invention also provides an electronic device, comprising: a processor, a communication interface, a memory, and a communication bus, wherein the processor, communication interface, and memory communicate with each other via the communication bus. The communication bus can be used for information transmission between the electronic device and sensors. The processor can call logical instructions in the memory to execute the following method: Step 1: Calculate the wheel-end torque demand in manual driving mode based on the limiting torque, throttle opening, and electric drive axle speed ratio corresponding to the front and rear axle motor speeds, combined with the actual vehicle speed and accelerator pedal opening; Step 2: Calculate the wheel-end torque demand in autonomous driving mode based on map information and road conditions; Step 3: Perform sliding window filtering on the calculated wheel-end torque demand value; Step 4: Calculate the wheel-end power demand in manual driving mode by combining the filtered wheel-end torque demand in manual driving mode with the actual vehicle speed; Step 5: Calculate the wheel-end power demand in autonomous driving mode by combining the filtered wheel-end torque demand in autonomous driving mode with tire speed and forward / reverse coefficients.

[0175] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0176] This invention provides a non-transitory computer-readable storage medium storing computer instructions that cause a computer to execute the method provided in the above-described method embodiments. For example, the instructions include: Step 1: Calculating the wheel-end torque requirement in manual driving mode based on the limiting torque, throttle opening, and electric drive axle speed ratio corresponding to the front and rear axle motor speeds, combined with the actual vehicle speed and accelerator pedal opening; Step 2: Calculating the wheel-end torque requirement in autonomous driving mode based on map information and road conditions; Step 3: Performing sliding window filtering on the calculated wheel-end torque requirement; Step 4: Calculating the wheel-end power requirement in manual driving mode by combining the filtered wheel-end torque requirement with the actual vehicle speed; Step 5: Calculating the wheel-end power requirement in autonomous driving mode by combining the filtered wheel-end torque requirement with tire speed and forward / reverse coefficients.

[0177] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A method for calculating the required torque and power at the wheel end of a flatbed truck, characterized in that, The steps include the following: The wheel-end torque required in manual driving mode is calculated based on the limiting torque corresponding to the front and rear axle motor speeds, accelerator pedal opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening. Calculate the wheel-end torque requirement for autonomous driving mode based on map information and road conditions; The calculated wheel-end torque demand value is then subjected to sliding window filtering. The wheel-end demand torque in the filtered manual driving mode is combined with the actual vehicle speed to calculate the wheel-end demand power in the manual driving mode. The wheel-end power demand of the autonomous driving mode is calculated by combining the filtered wheel-end torque demand with the tire speed and forward / backward coefficients. The steps for calculating the wheel-end torque requirement in manual driving mode based on the limiting torque at the front and rear axle motor speeds, accelerator pedal opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening include: The reference wheel end torque is calculated based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal opening, and the electric drive axle speed ratio. A model is established based on the actual vehicle speed and accelerator pedal opening to calculate the undetermined wheel-end torque related to vehicle speed; Calculate the difference between the reference wheel end torque requirement and the undetermined wheel end torque requirement; The recursive least squares algorithm is used to adjust the parameters of the model based on the magnitude and direction of the difference, so as to obtain the wheel-end torque requirement in the manual driving mode.

2. The method for calculating the required torque and power at the wheel end of a flatbed truck according to claim 1, characterized in that, The steps for calculating the reference wheel end torque based on the limiting torque at the front and rear axle motor speeds, accelerator pedal opening, and electric drive axle speed ratio include: The reference torque required at the front axle wheel end is obtained by multiplying the current speed of the front axle main motor corresponding to the limiting torque by the accelerator pedal opening. The reference torque required at the rear axle wheel end is obtained by multiplying the current speed of the rear axle main motor corresponding to the limiting torque by the accelerator pedal opening. The reference wheel-end torque is obtained by multiplying the front axle wheel-end reference torque and the rear axle wheel-end reference torque by the electric drive axle speed ratio and then summing them.

3. The method for calculating the required torque and power at the wheel end of a flatbed truck according to claim 2, characterized in that, The steps for calculating the wheel-end torque requirement in autonomous driving mode based on map information and road conditions include: Calculate the percentage of torque required based on map information and road conditions; The limit torque value is obtained by summing the limit torque corresponding to the current speed of the front axle main motor and the limit torque corresponding to the current speed of the rear axle main motor. The wheel-end torque requirement in autonomous driving mode is obtained by multiplying the limit torque, the percentage of required torque, and the electric drive axle speed ratio.

4. The method for calculating the required torque and power at the wheel end of a flatbed truck according to claim 3, characterized in that, The steps for performing sliding window filtering on the calculated wheel-end torque demand value include: Define the size of the sliding time window; Obtain the wheel-end torque demand value within the sliding time window and process the obtained wheel-end torque demand value; specifically, this includes: replacing the wheel-end torque demand value that is greater than the torque limit with the torque limit, and performing zero-crossing processing on the wheel-end torque demand value when the motor torque changes from negative torque or zero torque to positive torque, or from positive torque or zero torque to negative torque; After processing, the average torque within the sliding time window is calculated and recorded as the smoothed wheel end demand torque value, which is the wheel end demand torque value after filtering.

5. The method for calculating the required torque and power at the wheel end of a flatbed truck according to claim 4, characterized in that, The steps for calculating the wheel-end power demand in manual driving mode by combining the filtered wheel-end torque demand with the actual vehicle speed include: The wheel-end torque demand T_wheel-end after filtering in the manual driving mode is combined with the actual vehicle speed to calculate the reference wheel-end power demand W_reference = V_vehicle_speed * T_wheel-end * 1000 / (9550 * 60 * 2 * 3.14 * R_tire). Calculate the wheel-end traction force based on the actual vehicle speed and weight; A model is established based on the wheel-end traction force and actual vehicle speed to calculate the required power at the undetermined wheel-end; Calculate the difference between the reference wheel-end power demand and the undetermined wheel-end power demand; The recursive least squares algorithm is used to adjust the model parameters based on the magnitude and direction of the difference to obtain the wheel-end power demand in the manual driving mode.

6. The method for calculating the required torque and power at the wheel end of a flatbed truck according to claim 5, characterized in that, The steps for calculating the wheel-end power demand in autonomous driving mode by combining the filtered wheel-end torque demand with tire speed and forward / reverse coefficients include: The wheel-end power requirement of the autonomous driving mode is obtained by multiplying the wheel-end torque requirement, tire speed, and forward / reverse coefficients after filtering and dividing by a set constant.

7. A device for calculating the required torque and power at the wheel end of a flatbed truck, characterized in that, It includes a manual mode torque demand calculation module, an autonomous driving mode torque demand calculation module, a filtering module, a manual mode power demand calculation module, and an autonomous driving power demand calculation module; The manual mode torque demand calculation module is used to calculate the wheel end torque demand in manual driving mode based on the limiting torque corresponding to the front and rear axle motor speeds, accelerator pedal opening, electric drive axle speed ratio, and actual vehicle speed and accelerator pedal opening. The autonomous driving mode torque demand calculation module is used to calculate the wheel-end torque demand in autonomous driving mode based on map information and road conditions. The filtering module is used to perform sliding window filtering on the calculated wheel end torque demand value; The manual driving mode power demand calculation module is used to calculate the wheel-end power demand in the manual driving mode by combining the filtered wheel-end torque demand with the actual vehicle speed. The autonomous driving power demand calculation module is used to calculate the wheel-end power demand of the autonomous driving mode by combining the filtered wheel-end torque demand with the tire speed and forward / backward coefficients. The steps for calculating the wheel-end torque requirement in manual driving mode based on the limiting torque at the front and rear axle motor speeds, accelerator pedal opening, electric drive axle speed ratio, actual vehicle speed, and accelerator pedal opening include: The reference wheel end torque is calculated based on the limiting torque corresponding to the front and rear axle motor speeds, the accelerator pedal opening, and the electric drive axle speed ratio. A model is established based on the actual vehicle speed and accelerator pedal opening to calculate the undetermined wheel-end torque related to vehicle speed; Calculate the difference between the reference wheel end torque requirement and the undetermined wheel end torque requirement; The recursive least squares algorithm is used to adjust the parameters of the model based on the magnitude and direction of the difference, so as to obtain the wheel-end torque requirement in the manual driving mode.

8. An electronic device, characterized in that, The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores computer program instructions executable by the at least one processor, the computer program instructions being executed by the at least one processor to enable the at least one processor to perform the flatbed wheel end demand torque and power calculation method as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that cause the computer to execute the method for calculating the required torque and power at the wheel end of a flatbed truck as described in any one of claims 1 to 6.

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