A starting control method for a hybrid heavy-duty commercial vehicle

Abstract

The present invention relates to the field of automatic mechanical transmission control of hybrid heavy-duty commercial vehicles, and provides a hybrid heavy-duty commercial vehicle starting control method. By collecting vehicle-related signals and calculating the collected signals to obtain starting resistance and torque, the torque is respectively distributed according to the current vehicle mode, and the situation after the whole vehicle starts is judged. The torque is controlled by an actuator using a fuzzy PID algorithm to ensure the coordination among a clutch, an engine and a motor, so that the hybrid heavy-duty commercial vehicle can start smoothly on a slope road surface, and the starting performance and slope anti-slip problems of the hybrid heavy-duty commercial vehicle under slope road conditions are effectively solved.

Description

Technical Field

[0001] The invention relates to the field of automatic mechanical transmission control for hybrid heavy-duty commercial vehicles, and in particular to a starting control method for hybrid heavy-duty commercial vehicles. Background Art

[0002] Since hybrid heavy-duty commercial vehicles have multiple power sources, their starting process is relatively complicated and involves many situations, especially when starting on a slope. When starting in different modes such as pure electric, hybrid and fuel, it is necessary to coordinate and control the engine, clutch and motor at the same time, and it is necessary to ensure slope anti-slip and starting smoothness. Accurate and real-time calculation of the torque required by the vehicle is the key to improving starting smoothness, and reasonable allocation of motor and engine torque is the focus of improving fuel economy. On the other hand, in the process of starting on a heavy slope with a heavy load, it is necessary to coordinate and prioritize power. Therefore, hybrid heavy-duty commercial vehicles not only need to solve the economy and smoothness problems of traditional fuel vehicles during the starting process, but also need to solve the slope anti-slip problem of pure electric vehicles during the starting process, and when the vehicle is in a hybrid state, all of the above problems need to be solved simultaneously. Summary of the invention

[0003] In view of the problems of starting performance and slope anti-slipping of hybrid heavy-duty commercial vehicles on sloped road conditions in the prior art, the present invention provides a starting control method for a hybrid heavy-duty commercial vehicle, which effectively solves the problems of starting performance and slope anti-slipping of hybrid heavy-duty commercial vehicles on sloped road conditions.

[0004] The present invention is achieved through the following technical solutions:

[0005] A hybrid heavy-duty commercial vehicle starting control method comprises the following steps:

[0006] Step 1, collecting vehicle weight signal, ramp signal, ramp signal, gear signal, throttle signal and brake signal of a hybrid heavy-duty commercial vehicle;

[0007] Step 2, calculating the starting resistance f(t) by using the collected vehicle weight signal, ramp signal, ramp signal, gear signal, throttle signal and brake signal of the hybrid heavy-duty commercial vehicle according to the vehicle dynamics equation;

[0008] Step 3, the starting resistance f(t) is used to calculate the required torque cal(t) of the whole vehicle according to the transmission system parameters;

[0009] Step 4, distributes the torque cal(t) according to the current vehicle mode, monitors the vehicle's backward slip and vibration simultaneously, and determines whether the vehicle slips backward or has obvious impact when starting. When it is determined that the vehicle slips backward or has obvious impact when starting, re-identify the ramp signal and vehicle weight signal, and return to execute step 2 to calculate the starting resistance; otherwise, determine whether the vehicle has completed the start, and adjust the torque in real time through the actuator. When it is determined that the vehicle has not completed the start, the vehicle restarts and re-executes step 4. Otherwise, the ramp start work of the hybrid heavy-duty commercial vehicle is terminated.

[0010] Preferably, in step 2, the calculation formula of the starting resistance f(t) is calculated according to the vehicle dynamics equation as follows:

[0011] Calculating rolling resistance: F f =Gf cosγ;

[0012] Calculate the slope resistance: F i =G sinγ;

[0013] Calculate the acceleration resistance:

[0014] Calculate the starting resistance: F z =F f +F i +F j ;

[0015] Among them: F f represents rolling resistance; G represents vehicle weight; f represents rolling resistance coefficient; γ represents road slope; F i Indicates the slope resistance; F j represents the acceleration resistance; σ represents the vehicle rotation mass conversion factor; m represents the vehicle mass in kg; Indicates driving acceleration (m / s 2 );F z Indicates starting resistance.

[0016] Preferably, in step 3, the formula for calculating the torque cal(t) required for the whole vehicle from the transmission system parameters is as follows:

[0017]

[0018] Among them, T r Indicates torque; F z represents starting resistance; r represents tire rolling radius; i represents transmission ratio of transmission system; η represents mechanical efficiency of transmission system.

[0019] Preferably, in step 4, the current vehicle starting mode includes a pure electric mode, a fuel mode and a hybrid power mode.

[0020] Furthermore, the current vehicle mode distributes the torque cal(t) as follows:

[0021] In pure electric mode, all torque cal(t) is distributed to the motor mot(t);

[0022] The fuel mode distributes all the torque cal(t) to the engine eng(t);

[0023] The hybrid mode distributes the torque cal(t) to the motor mot(t) and the engine eng(t) respectively.

[0024] Preferably, in step 4, the torque cal(t) response is closed-loop control.

[0025] Preferably, in step 4, the method for judging whether the vehicle starts to slide backward or has obvious impact, and whether the vehicle has completed starting is as follows:

[0026] A threshold is set. When the vehicle speed is greater than the threshold, the actuator determines that the vehicle starting process is completed and enters the vehicle driving control logic; otherwise, the actuator adjusts the torque in real time to complete the vehicle starting process and enter the vehicle driving control logic.

[0027] Preferably, the actuator uses a fuzzy PID algorithm to control the torque, and the specific method steps are as follows:

[0028] S1, take the current sample value y(k);

[0029] S2, calculate the control deviation e(k) and the difference ec(k) between the current deviation and the previous deviation according to the current sampling value y(k);

[0030] S3, fuzzy processing is performed on the control deviation e(k) and the difference ec(k) between the current deviation and the previous deviation;

[0031] S4, by determining the PID control parameter fuzzy tuning deviation ratio Kp, deviation integral Ki and deviation differential Kd;

[0032] S5, determine the control amount U through the proportion Kp of the deviation, the integral Ki of the deviation and the differential Kd of the deviation, and judge whether the sampling is finished. If it is judged that the sampling is not finished, return to S1 to re-take the current sampling value y(k); otherwise, the sampling is finished.

[0033] Furthermore, in S3, the calculation formula of the control deviation e(k) is as follows:

[0034] e(k)=r(k)-y(k);

[0035] The calculation formula of the difference ec(k) between the current deviation and the previous deviation is as follows:

[0036] ec(k)=e(k)-e(k-1);

[0037] Among them, y(k) represents the current sampling value; r(k) represents the given target value; e(k) represents the control deviation; ec(k) represents the difference between the current deviation and the previous deviation.

[0038] Compared with the prior art, the present invention has the following beneficial technical effects:

[0039] The present invention provides a hybrid heavy-duty commercial vehicle starting control method, which collects vehicle-related signals and calculates the collected signals to obtain starting resistance and torque, distributes torque according to the current vehicle mode, and judges the situation of the whole vehicle after starting. The torque is controlled by an actuator using a fuzzy PID algorithm to ensure the coordination among the clutch, the engine and the motor, so that the hybrid heavy-duty commercial vehicle can start smoothly on a slope road surface, and effectively solves the starting performance and slope anti-slip problems of the hybrid heavy-duty commercial vehicle under slope road conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flowchart of the steps of the hybrid heavy-duty commercial vehicle starting control method of the present invention;

[0041] Figure 2 It is a judgment algorithm logic diagram of the hybrid heavy-duty commercial vehicle starting control method in the present invention;

[0042] Figure 3 This is a logic diagram of the actuator in the present invention using a fuzzy PID algorithm to control torque;

[0043] Figure 4 Schematic diagram of sampling data input in the present invention;

[0044] Figure 5 It is the torque distribution result and vehicle starting simulation diagram in the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0048] See also Figure 1 In one embodiment of the present invention, a hybrid heavy-duty commercial vehicle starting control method is provided, which effectively solves the starting performance and slope anti-slip problems of the hybrid heavy-duty commercial vehicle under slope conditions.

[0049] Specifically, the hybrid heavy-duty commercial vehicle starting control method comprises the following steps:

[0050] Step 1, collecting vehicle weight signal, ramp signal, ramp signal, gear signal, throttle signal and brake signal of a hybrid heavy-duty commercial vehicle;

[0051] Step 2, calculating the starting resistance f(t) by using the collected vehicle weight signal, ramp signal, ramp signal, gear signal, throttle signal and brake signal of the hybrid heavy-duty commercial vehicle according to the vehicle dynamics equation;

[0052] Step 3, the starting resistance f(t) is used to calculate the required torque cal(t) of the whole vehicle according to the transmission system parameters;

[0053] Step 4, distributes the torque cal(t) according to the current vehicle mode, monitors the vehicle's backward slip and vibration simultaneously, and determines whether the vehicle slips backward or has obvious impact when starting. When it is determined that the vehicle slips backward or has obvious impact when starting, re-identify the ramp signal and vehicle weight signal, and return to execute step 2 to calculate the starting resistance; otherwise, determine whether the vehicle has completed the start, and adjust the torque in real time through the actuator. When it is determined that the vehicle has not completed the start, the vehicle restarts and re-executes step 4. Otherwise, the ramp start work of the hybrid heavy-duty commercial vehicle is terminated.

[0054] Specifically, in step 2, the calculation formula of the starting resistance f(t) is calculated according to the vehicle dynamics equation as follows:

[0055] Calculating rolling resistance: Ff =Gf cosγ;

[0056] Calculate the slope resistance: F i =G sinγ;

[0057] Calculate the acceleration resistance:

[0058] Calculate the starting resistance: F z =F f +F i +F j ;

[0059] Among them: F f represents rolling resistance; G represents vehicle weight; f represents rolling resistance coefficient; γ represents road slope; F i Indicates the slope resistance; F j represents the acceleration resistance; σ represents the vehicle rotation mass conversion factor; m represents the vehicle mass (kg); Indicates driving acceleration (m / s 2 );F z Indicates starting resistance.

[0060] Specifically, in step 3, the formula for calculating the torque cal(t) required for the vehicle using the transmission system parameters is as follows:

[0061]

[0062] Among them, T r Indicates torque; F z represents starting resistance; r represents tire rolling radius; i represents transmission ratio of transmission system; η represents mechanical efficiency of transmission system.

[0063] Specifically, in step 4, the current vehicle starting mode includes pure electric mode, fuel mode and hybrid power mode.

[0064] Among them, the current vehicle mode distributes the torque cal(t) as follows:

[0065] In pure electric mode, all torque cal(t) is distributed to the motor mot(t);

[0066] The fuel mode distributes all the torque cal(t) to the engine eng(t);

[0067] The hybrid mode distributes the torque cal(t) to the motor mot(t) and the engine eng(t) respectively.

[0068] Specifically, in step 4, the method for judging whether the vehicle starts to slide backward or has obvious impact, and whether the vehicle has completed starting is as follows:

[0069] A threshold is set. When the vehicle speed is greater than the threshold, the actuator determines that the vehicle starting process is completed and enters the vehicle driving control logic; otherwise, the actuator adjusts the torque in real time to complete the vehicle starting process and enter the vehicle driving control logic.

[0070] Specifically, the actuator uses fuzzy PID algorithm to control the torque. Figure 3 As shown, the specific steps are as follows:

[0071] S1, take the current sample value y(k);

[0072] S2, calculate the control deviation e(k) and the difference ec(k) between the current deviation and the previous deviation according to the current sampling value y(k);

[0073] S3, fuzzy processing is performed on the control deviation e(k) and the difference ec(k) between the current deviation and the previous deviation;

[0074] Among them, the calculation formula of control deviation e(k) is as follows:

[0075] e(k)=r(k)-y(k);

[0076] The calculation formula of the difference ec(k) between the current deviation and the previous deviation is as follows:

[0077] ec(k)=e(k)-e(k-1);

[0078] Among them, y(k) represents the current sampling value; r(k) represents the given target value; e(k) represents the control deviation; ec(k) represents the difference between the current deviation and the previous deviation.

[0079] S4, by determining the PID control parameter fuzzy tuning deviation ratio Kp, deviation integral Ki and deviation differential Kd;

[0080] S5, determine the control amount U through the proportion Kp of the deviation, the integral Ki of the deviation and the differential Kd of the deviation, and judge whether the sampling is finished. If it is judged that the sampling is not finished, return to S1 to re-take the current sampling value y(k); otherwise, the sampling is finished.

[0081] Example

[0082] A hybrid heavy commercial vehicle starting control method, such as Figure 2 As shown, the specific steps include:

[0083] The first step is to collect data, such as Figure 4 As shown;

[0084] The original signal in(t) required for the vehicle to start is calculated through the sensors and algorithms installed on the vehicle. Figure 4It is the curve of the change of the sampling data in(t) of vehicle weight, throttle, gear and slope over time. The collected raw data is filtered to generate a more stable and reliable signal, and the signal is output to the starting resistance calculation module.

[0085] Step 2: Calculate the starting resistance

[0086] The collected vehicle weight signal, ramp signal, ramp signal, gear signal, throttle signal and brake signal of the hybrid heavy-duty commercial vehicle are used to calculate the starting resistance f(t) according to the vehicle dynamics equation;

[0087] The specific starting resistance mainly includes three parts (air resistance is ignored):

[0088] Calculating rolling resistance: F f =Gf cosγ;

[0089] Calculate the slope resistance: F i =G sinγ;

[0090] Calculate the acceleration resistance:

[0091] Calculate the starting resistance: F z =F f +F i +F j ;

[0092] Among them: F f represents rolling resistance; G represents vehicle weight; f represents rolling resistance coefficient; γ represents road slope; F i Indicates the slope resistance; F j represents the acceleration resistance; σ represents the vehicle rotation mass conversion factor; m represents the vehicle mass (kg); Indicates driving acceleration (m / s 2 );F z Indicates starting resistance.

[0093] The third step is to calculate the required torque cal(t) of the vehicle based on the starting resistance f(t) according to the transmission system parameters;

[0094] The formula for calculating the torque cal(t) required for the vehicle based on the transmission system parameters is as follows:

[0095]

[0096] Among them, T r Indicates torque; F z represents starting resistance; r represents tire rolling radius; i represents transmission ratio of transmission system; η represents mechanical efficiency of transmission system.

[0097] Calculate the required torque Tr Then, the torque is distributed according to the preset rules, such as Figure 5 shown.

[0098] Step 4: Mode determination

[0099] According to the vehicle mode signal, the current starting mode of the vehicle is determined, and different torque responses are allocated for the three different starting modes. The torque response is closed-loop control, and the rear slip and vibration of the vehicle are monitored simultaneously, and the control logic is adjusted in real time.

[0100] The current vehicle starting modes include pure electric mode, fuel mode and hybrid mode.

[0101] The current vehicle mode distributes the torque cal(t) as follows:

[0102] In pure electric mode, all torque cal(t) is distributed to the motor mot(t);

[0103] The fuel mode distributes all the torque cal(t) to the engine eng(t);

[0104] The hybrid mode distributes the torque cal(t) to the motor mot(t) and the engine eng(t) respectively.

[0105] Step 5: Determine whether the vehicle starts to slide backward or has obvious impact, and whether the vehicle has completed the start

[0106] The threshold is set to 2km / h. When it is determined that the vehicle speed is greater than a certain threshold of 2km / h, the control logic considers that the starting process is completed and enters the normal driving mode control logic.

[0107] In summary, the present invention provides a hybrid heavy-duty commercial vehicle starting control method, which collects vehicle-related signals and calculates the collected signals to obtain starting resistance and torque, distributes the torque according to the current vehicle mode, and judges the situation after the vehicle starts. The torque is controlled by the actuator using a fuzzy PID algorithm to ensure the coordination between the clutch, the engine, and the motor, so that the hybrid heavy-duty commercial vehicle can start smoothly on a slope road surface, effectively solving the starting performance and slope anti-skid problems of the hybrid heavy-duty commercial vehicle on slope road conditions.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A hybrid heavy commercial vehicle starting control method, characterized in that: The steps include: Step 1, collecting vehicle weight signal, ramp signal, gear signal, throttle signal and brake signal of a hybrid heavy-duty commercial vehicle; Step 2, calculating the starting resistance f(t) by using the collected vehicle weight signal, ramp signal, gear signal, throttle signal and brake signal of the hybrid heavy-duty commercial vehicle according to the vehicle dynamics equation; Step 3, the starting resistance f(t) is used to calculate the required torque cal(t) of the whole vehicle according to the transmission system parameters; Step 4, distributes the torque cal(t) according to the current vehicle mode, monitors the vehicle's backward slip and vibration simultaneously, and determines whether the vehicle slips backward or has obvious impact when starting. When it is determined that the vehicle slips backward or has obvious impact when starting, re-identify the ramp signal and vehicle weight signal, and return to execute step 2 to calculate the starting resistance; otherwise, determine whether the vehicle has completed the start, and adjust the torque in real time through the actuator. When it is determined that the vehicle has not completed the start, the vehicle restarts and re-executes step 4. Otherwise, the ramp start work of the hybrid heavy-duty commercial vehicle is terminated.

2. A hybrid heavy-duty commercial vehicle starting control method according to claim 1, characterized in that: In step 2, the calculation formula of the starting resistance f(t) is calculated according to the vehicle dynamics equation as follows: Calculating rolling resistance: F f =Gf cosγ; Calculate the slope resistance: F i =G sinγ; Calculate the acceleration resistance: Calculate the starting resistance: F z =F f +F i +F j ; Among them: F f represents rolling resistance; G represents vehicle weight; f represents rolling resistance coefficient; γ represents road slope; F i Indicates the slope resistance; F j represents the acceleration resistance; σ represents the vehicle rotation mass conversion factor; m represents the vehicle mass in kg; Indicates driving acceleration (m / s 2 );F z Indicates starting resistance.

3. A hybrid heavy-duty commercial vehicle starting control method according to claim 1, characterized in that: In step 3, the transmission system parameters are used to calculate the required torque cal(t) of the vehicle as follows: Among them, T r Indicates torque; F z represents starting resistance; r represents tire rolling radius; i represents transmission ratio of transmission system; η represents mechanical efficiency of transmission system.

4. A hybrid heavy commercial vehicle starting control method according to claim 1, characterized in that: In step 4, the current vehicle starting mode includes pure electric mode, fuel mode and hybrid mode.

5. A hybrid heavy commercial vehicle starting control method according to claim 4, characterized in that: The current vehicle mode distributes the torque cal(t) as follows: In pure electric mode, all torque cal(t) is distributed to the motor mot(t); The fuel mode distributes all the torque cal(t) to the engine eng(t); The hybrid mode distributes the torque cal(t) to the motor mot(t) and the engine eng(t) respectively.

6. A hybrid heavy commercial vehicle starting control method according to claim 1, characterized in that: In step 4, the torque cal(t) response is closed-loop controlled.

7. A hybrid heavy-duty commercial vehicle starting control method according to claim 1, characterized in that: In step 4, the method for judging whether the vehicle starts to slide backward or has obvious impact, and whether the vehicle has completed starting is as follows: A threshold is set. When the vehicle speed is greater than the threshold, the actuator determines that the vehicle starting process is completed and enters the vehicle driving control logic; otherwise, the actuator adjusts the torque in real time to complete the vehicle starting process and enter the vehicle driving control logic.

8. The hybrid heavy-duty commercial vehicle starting control method according to claim 1, characterized in that: The actuator uses fuzzy PID algorithm to control the torque. The specific steps are as follows: S1, take the current sample value y(k); S2, calculate the control deviation e(k) and the difference ec(k) between the current deviation and the previous deviation according to the current sampling value y(k); S3, fuzzy processing is performed on the control deviation e(k) and the difference ec(k) between the current deviation and the previous deviation; S4, by determining the PID control parameter fuzzy tuning deviation ratio Kp, deviation integral Ki and deviation differential Kd; S5, determine the control amount U through the proportion Kp of the deviation, the integral Ki of the deviation and the differential Kd of the deviation, and judge whether the sampling is finished. If it is judged that the sampling is not finished, return to S1 to re-take the current sampling value y(k); otherwise, the sampling is finished.

9. A hybrid heavy commercial vehicle starting control method according to claim 8, characterized in that: In S3, the calculation formula of the control deviation e(k) is as follows: e(k)=r(k)-y(k); The calculation formula of the difference ec(k) between the current deviation and the previous deviation is as follows: ec(k)=e(k)-e(k-1); Among them, y(k) represents the current sampling value; r(k) represents the given target value; e(k) represents the control deviation; ec(k) represents the difference between the current deviation and the previous deviation.

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