Train AMT (automated mechanical transmission) override gear shifting coordination control method for electrically-driven trailer

Abstract

The invention relates to an AMT (automated mechanical transmission) override gear shifting coordination control method for an electric drive trailer. The AMT override gear shifting coordination control method comprises the following steps: acquiring driving intention information of a driver, acquiring vehicle running state parameter information and acquiring road condition information; driving style characteristics of the driver are analyzed through the driving intention information of the driver and the vehicle running state parameters, and an operation decision of the driver is completed; setting a control strategy based on the opening degree of the accelerator pedal; on the basis of the driving modes, a gear shifting strategy is set, the VCU completes adjustment of the transmission according to the different driving modes, gear shifting is achieved, and gear shifting comprises gear jumping, gear upshifting and gear downshifting; when the vehicle accelerates to run, based on the rotating speed of an engine, the opening degree of an accelerator pedal and the opening degree response time of the accelerator pedal, a jump gear and upshift control strategy is set; a downshift strategy is set based on the acceleration and gradient of the vehicle and the opening degree of an accelerator pedal under the overtaking or climbing working condition; the driver behaviors are switched and optimized, and the whole vehicle driving feeling and the whole vehicle dynamic property are improved.

Description

Technical Field

[0001] The present invention relates to the field of commercial vehicle control technology, and in particular to a coordinated control method for an AMT skip-shift of an electric drive trailer. Background Art

[0002] In recent years, automatic transmission technology for commercial vehicles has become a trend, and major domestic commercial vehicle manufacturers are also developing and promoting it. More and more commercial vehicles in my country are equipped with AMT (automatic transmission), and the popularization of AMT in commercial vehicles has become a trend. The shifting quality and fuel consumption of AMT will directly affect the satisfaction of passengers with the vehicle, so major automobile manufacturers have invested a lot of effort in researching it.

[0003] With continuous improvement, AMT has shown many advantages over the widely used manual transmission. The main advantages are: ① It can effectively reduce the driver's operating intensity, and the operation is easy, reducing labor intensity and improving safety when participating in traffic. ② It can automatically shift gears when encountering different driving sections, improving vehicle power and fuel economy, and reducing vehicle exhaust emissions; the current heavy-duty commercial vehicle AMT shift strategy is mainly aimed at matching input parameters such as the accelerator pedal and road slope. Due to the inability to identify road conditions and the driver's driving habits, the shifting is not timely, and the driving performance is not as good as the driver's manual transmission. In some working conditions, the skipping operation cannot be performed. Summary of the invention

[0004] The purpose of the present invention is to provide a coordinated control method for the AMT skip-shift of an electric drive trailer vehicle train in view of the deficiencies in the prior art.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] A coordinated control method for AMT skip-shifting of an electric drive trailer vehicle train, comprising:

[0007] S1, driving information collection, including driver driving intention information collection, vehicle operation status parameter information collection and road condition information collection;

[0008] S2, driver driving style judgment, analyzing and judging the driver's driving style characteristics through the driver's driving intention information and vehicle operating status parameters, and completing the driver's operation decision;

[0009] S3, defining the accelerator pedal opening, and based on the accelerator pedal opening a, setting the AMT control strategy to no throttle signal A0, low throttle area A1, medium throttle area A2, high throttle area A3 and full throttle area A4;

[0010] S4. Define the shift schedule: Based on the driving mode, set the AMT shift strategy to economy mode, normal mode, and power mode. The vehicle control unit (VCU) adjusts the transmission according to different driving modes to achieve shifting, where shifting includes skipping gears, upshifting, and downshifting.

[0011] S5. Define the skip-gear and upshift strategies: When the vehicle is accelerating, based on the engine speed, throttle pedal opening, and throttle pedal opening response time, set the skip-gear and upshift control strategies.

[0012] S6. Define the downshift strategy: Based on the vehicle acceleration and slope under overtaking or climbing conditions, and the throttle pedal opening changes from the low throttle region A1 to the high throttle region A3 or the full throttle region A4 within a short time, set it as the downshift strategy.

[0013] The articulated vehicle includes a tractor equipped with a 16-speed automatic transmission and a semi-trailer equipped with a 4-speed transmission.

[0014] Further, in S1, the road condition information includes the driving road surface slope and the road surface grade; the driving intention information and the vehicle operating state parameter information are obtained through in-vehicle sensors and the CAN bus. The vehicle operating state information includes vehicle mass, ramp slope parameter, and vehicle performance parameters. The vehicle performance parameters include engine speed, torque, vehicle speed, current gear, target gear, input shaft speed, throttle pedal position, brake pedal position, longitudinal acceleration, torque signal, altitude, slope, instantaneous fuel consumption, cumulative fuel consumption, and driving mileage.

[0015] Further, in S3, the no-throttle signal A0 is a = 0%, the low throttle region A1 is 0% < a ≤ 30%, the medium throttle region A2 is 30% < a ≤ 60%, the high throttle region A3 is 60% < a ≤ 90%, and the full throttle region A4 is 90% < a ≤ 100%.

[0016] Further, in S5, when driving the vehicle to accelerate on a road with a road surface slope of 0, if the throttle pedal opening a uses the no-throttle signal A0, the low throttle region A1, the medium throttle region A2 for positioning, or the throttle pedal opening a does not reach the high throttle region A3 or the full throttle region A4 for positioning, and the throttle pedal opening response time is less than the set value T1, then execute the upshift strategy; if the throttle pedal opening a uses the high throttle region A3 or the full throttle region A4 for positioning and the throttle pedal opening response time is greater than the set value T1, then execute the skip-gear strategy.

[0017] Further, in S6, under overtaking or climbing conditions, the vehicle acceleration is greater than 0 m / s 2, the accelerator pedal opening changes from the low throttle area A1 to the high throttle area A3 or the full throttle area A4 in a short time, and the accelerator pedal opening is positioned in the high throttle area A3 or the full throttle area A4, then the downshift strategy is executed.

[0018] Furthermore, in order to ensure the relative stability of the vehicle state before and after the gear shift, the resistance encountered by the main vehicle and the electric drive axle trailer during the driving process should be evaluated before the gear shift, and the change in the speed of the main vehicle and the electric drive axle trailer during the gear shift should be calculated based on the resistance of the main vehicle and the electric drive axle trailer, and then the change in the speed of the main vehicle and the electric drive axle trailer is converted into a corresponding speed compensation, and then the engine speed is adjusted to improve the efficiency of the leapfrog gear shift; the speed compensation is:

[0019] a 阻 =-F 阻 / δM

[0020] In the formula, α 阻 is the resistance deceleration, F 阻 is the driving resistance, M is the total mass of the vehicle after loading, and δ is the change in the total mass of the vehicle after loading.

[0021] Furthermore, in order to avoid speed loss during gear shifting, the speed during gear shifting needs to be adjusted to achieve dynamic adjustment of the speed during gear shifting:

[0022] V actshift =V shift +|ΔV|; ΔV=t shift ×a 阻

[0023] In the formula, α 阻 is the resistance deceleration, V actshift To compensate for the rear shift speed, V shift is the actual shift speed, ΔV is the speed compensation, t shift The power cut-off time.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] Based on the analysis of the throttle opening under the driver's behavior, the shifting strategy of the driver's throttle behavior is switched and optimized by defining different throttle opening distributions on flat roads, uphill and downhill, thereby improving the driving experience and power of the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of the control system of the present invention;

[0027] Figure 2 The process of the second embodiment of the present invention Figure 1 ;

[0028] Figure 3 The process of the second embodiment of the present invention Figure 2 ;

[0029] Figure 4 The process of the third embodiment of the present invention Figure 1 ;

[0030] Figure 5 The process of the third embodiment of the present invention Figure 2 . DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions 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.

[0032] Example 1

[0033] When developing a skip-shift strategy, the degree of accelerator pedal depression, the steepness of the slope, the vehicle's heavy load, and the driving state when cornering should be considered;

[0034] Accelerator: 0%, 30%, 60%, 90%, 100%;

[0035] Positive slope: 0%, 0%-1.5%, 1.5%-3%, 3%-4.5%, 4.5%-6%, 6%-8%, greater than 8%;

[0036] Negative slope: corresponds to a positive slope value

[0037] Vehicle weight: 20 tons, 25 tons, 30 tons, 35 tons, 40 tons, 45 tons, 50 tons;

[0038] The transmission devices of the main vehicle and the electric drive axle trailer need to make comprehensive judgments based on the accelerator pedal position, slope and vehicle weight to achieve coordinated control of overtaking shift operations.

[0039] like Figure 1 As shown, a coordinated control method for AMT skip-shifting of an electric drive trailer vehicle train includes:

[0040] S1, driving information collection, including driver driving intention information collection, vehicle operation status parameter information collection and road condition information collection;

[0041] S2. Driver driving style judgment: Analyze and judge the driver's driving style characteristics through the driver's driving intention information and vehicle operating state parameters to complete the driver's operation decision-making;

[0042] S3. Define the throttle pedal opening. Based on the throttle pedal opening a, set the AMT control strategy as no throttle signal A0, low throttle area A1, medium throttle area A2, high throttle area A3, and full throttle area A4;

[0043] S4. Define the shift rule: Based on the driving mode, set the AMT shift strategy as economy mode, normal mode, and power mode. The vehicle control unit VCU adjusts the transmission according to different driving modes to achieve shifting, where shifting includes skip shifting, upshifting, and downshifting;

[0044] S5. Define the skip shifting and upshifting strategies: When the vehicle is accelerating, set the skip shifting and upshifting control strategies based on the engine speed, throttle pedal opening, and throttle pedal opening response time;

[0045] S6. Define the downshifting strategy: Based on the vehicle acceleration and slope under overtaking or climbing conditions, and the throttle pedal opening changes from the low throttle area A1 to the high throttle area A3 or the full throttle area A4 within a short time, set it as the downshifting strategy.

[0046] The articulated vehicle includes a tractor with a 16-speed automatic transmission and an electric drive axle trailer with a 4-speed transmission.

[0047] In S1, the road condition information includes the driving road surface slope and road surface grade; the driving intention information and vehicle operating state parameter information are obtained through on-vehicle sensors and the CAN bus. The vehicle operating state information includes vehicle mass, ramp slope parameter, and vehicle performance parameters. The vehicle performance parameters include engine speed, torque, vehicle speed, current gear, target gear, input shaft speed, throttle pedal position, brake pedal position, longitudinal acceleration, torque signal, altitude, slope, instantaneous fuel consumption, cumulative fuel consumption, and driving mileage.

[0048] In S3, the no throttle signal A0 is a = 0%, the low throttle area A1 is 0% < a ≤ 30%, the medium throttle area A2 is 30% < a ≤ 60%, the high throttle area A3 is 60% < a ≤ 90%, and the full throttle area A4 is 90% < a ≤ 100%.

[0049] In S5, when the vehicle is accelerating on a road with a road slope of 0, the throttle pedal opening a is positioned using the no throttle signal A0, low throttle area A1, medium throttle area A2, or the throttle pedal opening a does not reach the high throttle area A3, full throttle area A4, and the throttle pedal opening response time is less than the set value T1, then the upshift strategy is executed; if the throttle pedal opening a is positioned using the high throttle area A3, full throttle area A4, and the throttle pedal opening response time is greater than the set value T1, then the shift skipping logic is activated and the shift skipping strategy is executed.

[0050] When the driver applies a large throttle, that is, the throttle opening a is positioned in the high throttle area A3 and the full throttle area A4, the driver has a demand for rapid acceleration of the vehicle. At this time, the engine outputs a large torque and the vehicle starts to accelerate. The driver continues to apply a large throttle and the vehicle continues to accelerate. That is, the throttle pedal opening response time is greater than the set value T1, and the gear skipping condition is met, then the gear skipping logic is activated and the gear skipping strategy is executed;

[0051] If the driver applies the accelerator for too short a time, the vehicle accelerates and then quickly returns to normal speed, that is, the accelerator pedal opening response time is less than the set value T1, the engine speed increases too little, and the shift-skipping conditions are not met, then the shift-skipping logic cannot be activated.

[0052] Taking a 16-speed gearbox as an example, if all conditions are met and the gear-skipping strategy is executed, it is feasible to achieve 2nd or 3rd gear by gear-skipping:

[0053] 2nd gear skipping: When the current vehicle speed increases to the next gear upshift speed, the skipping logic is activated. The highest gear to skip is 13th gear, and no skipping is allowed above 13th gear. Shifting starts from 13th gear and starts in sequence.

[0054] 3rd gear skipping: When the current vehicle speed increases to the next gear upshift speed, the skipping logic is activated. The highest gear to skip is 12th gear. No skipping is allowed above 12th gear. Shifting starts from 12th gear and then shifts up sequentially.

[0055] When skipping gears, the traction vehicle can accelerate across 3 gears, while the electric drive axle is set to skip the upshift operation from 2 gears.

[0056] In S6, the vehicle acceleration is greater than 0 m / s in overtaking or climbing conditions. 2 , the accelerator pedal opening changes from the low throttle area A1 to the high throttle area A3 or the full throttle area A4 in a short time, and the accelerator pedal opening is positioned in the high throttle area A3 or the full throttle area A4, then the downshift strategy is executed.

[0057] When the vehicle turns, the turning angle sensor is used for monitoring. If the turning angle exceeds 45 degrees, the electric drive axle trailer will not be able to perform upshift or downshift. When the turning angle is less than 45 degrees, the electric drive axle trailer is only allowed to perform one gear change.

[0058] During the process of shifting up, the tractor can shift up to 3 gears, while the electric drive axle has the ability to keep the gear unchanged, shift up one gear, or shift up two gears.

[0059] When shifting up to overtaking gear, the tractor can downshift up to 3 gears, while the electric drive axle can flexibly choose not to downshift, downshift by one gear or downshift by two gears.

[0060] In view of the fast shifting speed of the four-speed transmission, in order to protect the speed of the electric motor, its transmission system can only support a maximum downshift of two gears.

[0061] To ensure the relative stability of the vehicle state before and after the gear shift, the resistance encountered by the main vehicle and the electric drive axle trailer during the driving process should be evaluated before the gear shift, and the change in the speed of the main vehicle and the electric drive axle trailer during the gear shift should be calculated based on the resistance of the main vehicle and the electric drive axle trailer, and then the change in the speed of the main vehicle and the electric drive axle trailer is converted into the corresponding speed compensation, and then the engine speed is adjusted to improve the efficiency of the leapfrog gear shift;

[0062] The speed compensation is:

[0063] a 阻 =-F 阻 / δM

[0064] In the formula, α 阻 is the resistance deceleration, F 阻 is the driving resistance, M is the total mass of the vehicle after loading, and δ is the change in the total mass of the vehicle after loading.

[0065] Furthermore, in order to avoid speed loss during gear shifting, the speed during gear shifting needs to be adjusted to achieve dynamic adjustment of the speed during gear shifting:

[0066] V actshift =V shift +|ΔV|; ΔV=t shift ×a 阻

[0067] In the formula, α 阻 is the resistance deceleration, V actshift To compensate for the rear shift speed, V shift is the actual shift speed, ΔV is the speed compensation, t shift The power cut-off time.

[0068] Example 2

[0069] like Figure 2-Figure 3 As shown:

[0070] When driving on a straight road, during normal acceleration and shifting, the main vehicle can shift up to 2 or 3 gears according to the torque requested by the driver; during the process of the main vehicle shifting up to 2 gears, the electric drive axle trailer can implement the strategy of not shifting up, shifting up to 1 gear or shifting up to 2 gears; during the process of the main vehicle shifting up to 3 gears, the electric drive axle trailer can implement the strategy of shifting up to 1 gear or shifting up to 2 gears;

[0071] When driving on a straight road, during the downshifting process of sudden acceleration and overtaking, the main vehicle can be downshifted by 2 or 3 gears according to the torque requested by the driver; during the downshifting process of the main vehicle to 2 gears, the electric drive axle trailer can execute the strategy of not downshifting, downshifting by 1 gear or downshifting by 2 gears; during the downshifting process of the main vehicle to 3 gears, the electric drive axle trailer can execute the strategy of not downshifting, downshifting by 1 gear or downshifting by 2 gears.

[0072] Example 3

[0073] like Figure 4-Figure 5 As shown:

[0074] During the curve driving process, in order to ensure the safety of vehicle driving and avoid excessive driving force output, the cross-shifting of the electric drive axle trailer is restricted.

[0075] When driving on a curved road, during normal acceleration and shifting, the main vehicle can shift up to 2 or 3 gears according to the torque requested by the driver; during the process of the main vehicle shifting up to 2 gears, the electric drive axle trailer can execute the strategy of not shifting up, or shifting up to 1 gear; during the process of the main vehicle shifting up to 3 gears, the electric drive axle trailer can execute the strategy of not shifting up, or shifting up to 1 gear.

[0076] When driving on a curve, during the process of sudden acceleration and downshifting, the main vehicle can be downshifted to 2 or 3 gears according to the torque requested by the driver; during the process of the main vehicle downshifting to 2 gears, the electric drive axle trailer can execute the strategy of not downshifting but downshifting to 1 gear; during the process of the main vehicle downshifting to 3 gears, the electric drive axle trailer can execute the strategy of not downshifting but downshifting to 1 gear.

Claims

1. A coordinated control method for AMT shifting of an electric drive trailer vehicle train, characterized in that: It includes the following steps: S1, Driving information collection, including the collection of driver driving intention information, vehicle operating state parameter information, and road condition information; S2, Driver driving style judgment, analyzing and judging the driver's driving style characteristics through the driver driving intention information and vehicle operating state parameters to complete the driver's operation decision-making; S3, Defining the throttle pedal opening degree, based on the throttle pedal opening degree a, setting the AMT control strategy as no throttle signal A0, low throttle area A1, medium throttle area A2, high throttle area A3, and full throttle area A4; S4, Defining the shifting law, based on the driving mode, setting the AMT shifting strategy as economic mode, conventional mode, and power mode. The vehicle control unit VCU completes the adjustment of the transmission according to different driving modes to achieve shifting, where shifting includes skipping gears, upshifting, and downshifting; S5, Defining the skip gear and upshift strategy: When the vehicle is accelerating, based on the engine speed, throttle pedal opening degree, and throttle pedal opening degree response time, set it as the skip gear and upshift control strategy; S6, Defining the downshift strategy: Based on the vehicle acceleration and slope under overtaking or climbing conditions, and the throttle pedal opening degree changing from the low throttle area A1 to the high throttle area A3 or the full throttle area A4 within a short time, set it as the downshift strategy; The articulated vehicle includes a tractor equipped with a 16-speed automatic transmission and an electric drive axle trailer equipped with a 4-speed transmission.

2. The coordinated control method for AMT shifting of an electric drive trailer vehicle train according to claim 1 is characterized in that: In S1, the road condition information includes the driving road surface slope and the road surface grade; the driving intention information and vehicle operating state parameter information are obtained through in-vehicle sensors and the CAN bus. The vehicle operating state information includes vehicle mass, ramp slope parameter, and vehicle performance parameters. The vehicle performance parameters include engine speed, torque, vehicle speed, current gear, target gear, input shaft speed, throttle pedal position, brake pedal position, longitudinal acceleration, torque signal, altitude, slope, instantaneous fuel consumption, cumulative fuel consumption, and driving mileage.

3. The coordinated control method for AMT shifting of an electric drive trailer in a train according to claim 1 is characterized in that: In S3, the no throttle signal A0 is a = 0%, the low throttle area A1 is 0% < a ≤ 30%, the medium throttle area A2 is 30% < a ≤ 60%, the high throttle area A3 is 60% < a ≤ 90%, and the full throttle area A4 is 90% < a ≤ 100%.

4. The coordinated control method for AMT shifting of an electric drive trailer vehicle train according to claim 1 is characterized in that: In S5, when driving the vehicle to accelerate on a road with a road surface slope of 0, if the throttle pedal opening degree a uses the no throttle signal A0, the low throttle area A1, or the medium throttle area A2 for positioning, or the throttle pedal opening degree a does not reach the high throttle area A3 or the full throttle area A4 for positioning, and the throttle pedal opening degree response time is less than the set value T1, then execute the upshift strategy; If the throttle pedal opening degree a uses the high throttle area A3 or the full throttle area A4 for positioning and the throttle pedal opening degree response time is greater than the set value T1, then execute the skip gear strategy.

5. The coordinated control method for AMT skip-shifting of an electric drive trailer according to claim 1, characterized in that: In S6, the vehicle acceleration is greater than 0 m / s in overtaking or climbing conditions. 2 , the accelerator pedal opening changes from the low throttle area A1 to the high throttle area A3 or the full throttle area A4 in a short time, and the accelerator pedal opening is positioned in the high throttle area A3 or the full throttle area A4, then the downshift strategy is executed.

6. The coordinated control method for AMT skip-shifting of an electric drive trailer according to claim 5 is characterized in that: In order to ensure the relative stability of the vehicle state before and after the gear shift, the resistance encountered by the main vehicle and the electric drive axle trailer during the driving process should be evaluated before the gear shift, and the change in the speed of the main vehicle and the electric drive axle trailer during the gear shift should be calculated based on the resistance of the main vehicle and the electric drive axle trailer, and then the change in the speed of the main vehicle and the electric drive axle trailer is converted into the corresponding speed compensation, and then the engine speed is adjusted to improve the efficiency of the leapfrog gear shift; the speed compensation is: a 阻 =-F 阻 / δM In the formula, α 阻 is the resistance deceleration, F 阻 is the driving resistance, M is the total mass of the vehicle after loading, and δ is the change in the total mass of the vehicle after loading.

7. The coordinated control method for AMT shifting of an electric drive trailer in a train according to claim 6 is characterized in that: In order to avoid speed loss during gear shifting, the speed during gear shifting needs to be adjusted to achieve dynamic adjustment of the speed during gear shifting: V actshift =V shift +|ΔV|;ΔV=t shift ×a 阻 In the formula, α 阻 is the resistance deceleration, V actshift To compensate for the rear shift speed, V shift is the actual shift speed, ΔV is the speed compensation, t shift The power cut-off time.

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