A Terrain-Based Vehicle Dynamic Shift Control Method and System

Abstract

A vehicle dynamic shift control method and system based on terrain, which preset an economy shift strategy and a power shift strategy, includes the following steps: Step 1) When the vehicle is running, obtain the current terrain; Step 2) The shift controller performs dynamic interpolation fusion according to the current terrain, the economy shift strategy and the power shift strategy to generate the current shift strategy curve; Step 3) The shift controller controls the gearbox to shift gears according to the current shift strategy curve. The present invention can make the vehicle have a wider adaptability to different terrains and achieve a better dynamic balance between economy and power performance.

Description

Technical Field

[0001] The present invention relates to the field of vehicles, and particularly to a terrain-based dynamic shift control method and system for vehicles. Background Art

[0002] There are generally various shift laws for vehicle automatic transmissions. For example, most vehicles have a normal shift law (D gear) and a power shift law (S gear), and some vehicles also have an economic shift law (ECO gear). Economic shifting is suitable for use on downhill roads, and power shifting is suitable for working conditions with high power requirements such as uphill or heavy loads. Existing shift laws are generally fixed laws selected manually by the user. However, the slope of the road surface on which the vehicle travels changes frequently, and users generally do not frequently manually select the shift law. Moreover, the slopes vary in size, and a few fixed shift laws cannot adapt to all slopes.

[0003] Patent 201710318736.7 proposes a ramp condition automatic transmission shift control strategy based on vehicle mass and ramp. By identifying the vehicle mass, rolling resistance coefficient, and air resistance coefficient on a flat road surface, calibration quantities and known quantities are provided for identifying the vehicle mass and ramp slope during ramp driving, thereby improving the identification accuracy of vehicle mass and ramp slope; and ramp shift correction control is performed based on vehicle mass and ramp to avoid frequent shifting on ramps, thereby improving the shift smoothness and intelligent level of vehicle automatic transmission. Although the external environment is considered, the internal shift law is not substantially changed, but forced downshifting or upshifting methods are used, and only a few discrete shift strategies can be roughly corresponding to several discrete states such as gentle slopes and steep slopes of the discrete slopes. Summary of the Invention

[0004] The main object of the present invention is to overcome the deficiencies of the existing automatic shift control of vehicles, and to propose a terrain-based dynamic shift control method and system for vehicles, which generates a shift strategy curve in real time according to external terrain information, so that the vehicle has a wider adaptability to different terrains.

[0005] The present invention adopts the following technical solutions:

[0006] A terrain-based dynamic shift control method for vehicles, which presets an economic shift strategy and a power shift strategy, is characterized by including the following steps:

[0007] Step 1) When the vehicle is running, obtain the current terrain information of the vehicle;

[0008] Step 2) The shift controller performs dynamic interpolation fusion according to the current terrain information, the economic shift strategy, and the power shift strategy to generate the current shift strategy curve;

[0009] Step 3) The shift controller controls the gearshift of the gearbox according to the current shift strategy curve.

[0010] Preferably, the step 2) specifically includes:

[0011] Step 2.1) Calculate the proportionality coefficient of the interpolation fusion according to the current terrain information;

[0012] Step 2.2) Generate the current shift strategy curve according to the proportionality coefficient of the interpolation fusion, the shift curve of the corresponding gear in the economic shift strategy, and the shift curve of the corresponding gear in the power shift strategy.

[0013] Preferably, the maximum downhill value M1 corresponding to the preset economic strategy curve and the maximum uphill value M2 corresponding to the power strategy curve are set, and the proportionality coefficient of the interpolation fusion is K = |M - M1| / |M2 - M1|, where M is the slope value of the current terrain information.

[0014] Preferably, let A = Gn(V) represent the shift curve of the nth gear in the economic shift strategy, A = Fn(V) represent the shift curve of the nth gear in the power shift strategy, and A = D M _n(V) represent the shift curve of the nth gear in the shift strategy curve generated under the slope value M of the current terrain information, and the expression is as follows:

[0015] V = D -1 M _n (A) = (1 - K)G -1 n(A) + KF -1 n(A) (1)

[0016] F -1 n(A) represents the inverse function of Fn(V); D -1 M _n(A) represents the inverse function of D M _n(V), where n = 1, 2,..., N, N is the total number of gears of the gearbox, A is the throttle depth, and V is the vehicle speed.

[0017] Preferably, the step 3) specifically includes the following:

[0018] Step 3.1) Obtain the current gear of the vehicle, and obtain the upshift curve and downshift curve of the current gear according to the current shift strategy curve;

[0019] Step 3.2) According to the current throttle depth of the vehicle, calculate the vehicle speeds of the upshift curve and the downshift curve respectively by combining the expression (1) of the shift curve of the nth gear in the shift strategy curve.

[0020] Step 3.3) Compare the current vehicle speed of the vehicle with the vehicle speeds of the calculated upshift curve and downshift curve, and control whether the transmission shifts gears according to the comparison result.

[0021] Preferably, in the said step 3.3), first judge whether the current vehicle speed is greater than the vehicle speed of the upshift curve. If so, control the transmission to upshift; if not, then judge whether it is less than the vehicle speed of the downshift curve. If so, control the transmission to downshift; if not, then maintain the current gear.

[0022] Preferably, the shift curves of each gear of the economy shift strategy and the shift curves of each gear of the power shift strategy are respectively two-dimensional relationship curves of vehicle speed and throttle depth.

[0023] Preferably, in the said step 1), obtain the current terrain information through an electronic horizon.

[0024] A terrain-based vehicle dynamic shift control system, including a shift controller and a transmission. The shift controller is pre-set with an economy shift strategy and a power shift strategy. It is characterized in that: it further includes an electronic horizon module for obtaining the current terrain information of the vehicle when the vehicle is driving; the shift controller performs dynamic interpolation fusion according to the current terrain information, economy shift strategy and power shift strategy to generate the current shift strategy curve, and controls the transmission to shift gears according to the current shift strategy curve.

[0025] Preferably, the shift controller further includes a gear shift module and a shift strategy curve generation module; the shift strategy curve generation module performs dynamic interpolation fusion according to the current terrain information, the economy shift strategy and the power shift strategy to generate the current shift strategy curve; the gear shift module controls the transmission to shift gears according to the current shift strategy curve.

[0026] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The method and system of the present invention perform dynamic interpolation fusion according to the current terrain information, economy shift strategy and power shift strategy of the vehicle during driving to generate the current shift strategy curve, enabling the vehicle to have a wider adaptability to different terrains and achieving a better dynamic balance between economy and power.

[0028] 2. The method and system of the present invention calculate the proportional coefficient of interpolation fusion through the continuously changing geographical slope of the current terrain, and further combine the economy shift strategy and the power shift strategy to generate the shift strategy curve, and a continuous shift strategy curve can be obtained, improving the smoothness of gear shifting.

[0029] 3. The method and system of the present invention calculate the vehicle speeds of the upshift curve and the downshift curve respectively through the current gear position of the vehicle and the throttle depth in combination with the expression of the shift strategy curve, compare them with the current vehicle speed, and control whether the transmission shifts gears according to the comparison result, which can improve the driving performance of the driver and enhance the intelligent level of automatic gear shifting of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flowchart of the method of the present invention.

[0031] Figure 2 It is a system diagram of the present invention.

[0032] Figure 3 It is an upshift curve diagram of the economy shift strategy and the power shift strategy of the present invention.

[0033] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be further described below through specific embodiments.

[0035] A terrain-based vehicle dynamic shift control method presets an economy shift strategy and a power shift strategy in a shift controller. The shift curves of each gear of the economy shift strategy and the shift curves of each gear of the power shift strategy are two-dimensional relationship curves of vehicle speed and throttle depth, and both include an upshift curve and a downshift curve. The built-in economy strategy curve is more biased towards the vertical axis of the curve coordinate space. In practical applications, the shift curves of each gear of the economy shift strategy and the power shift strategy can also be three-parameter relationship curves of vehicle speed, throttle depth, and acceleration.

[0036] See Figure 3 the upshift curve diagrams of the economy shift strategy and the power shift strategy. Assuming they are the shift curves between the second gear and the third gear, including two upshift curves. At the same throttle depth or opening, the vehicle speed for shifting from the second gear to the third gear of the economy shift strategy is less than that of the power shift strategy.

[0037] See Figure 1 , the method of the present invention includes the following steps:

[0038] Step 1) When the vehicle is running, obtain the current terrain information of the vehicle. Specifically, the current terrain can be obtained through an electronic horizon, and the current terrain can include slope data, curve data, speed limit data, etc. In the embodiment provided by the present invention, preferably, obtain the slope data, that is, slope M.

[0039] In the present invention, the electronic horizon includes map data, GPS / Beidou positioning, a forward search engine, etc. It is characterized in that the positioning longitude and latitude position of the vehicle and the forward direction information of the vehicle are parsed according to the GPS / Beidou satellite positioning system, and the geographical information in front of the vehicle is searched on the electronic horizon map, and the geographical information in front is transmitted to the shift controller through the CAN bus or the Ethernet bus.

[0040] Step 2) The shift controller performs dynamic interpolation fusion according to the current terrain information, the economic shift strategy, and the power shift strategy to generate the current shift strategy curve. This step specifically includes:

[0041] Step 2.1) Calculate the proportionality coefficient of the interpolation fusion according to the current terrain information. Specifically, preset the maximum downhill value M1 corresponding to the economic strategy curve and the maximum uphill value M2 corresponding to the power strategy curve. For example, the maximum downhill value M1 can be set to a -3-degree slope, and the maximum uphill value M2 can be set to a +3-degree slope. Then the economic shift strategy is used when the maximum downhill value is -3, and the power shift strategy is used when the maximum uphill value is +3. The proportionality coefficient of the interpolation fusion is K = |M - M1| / |M2 - M1|, where M is the slope value of the current terrain information.

[0042] In the present invention, the calculation of the proportionality coefficient of the interpolation fusion is related to the currently obtained terrain data, which is not limited to the slope value and can also be other data.

[0043] Step 2.2) Generate the current shift strategy curve according to the proportionality coefficient of the interpolation fusion, the shift curve of the corresponding gear in the economic shift strategy, and the shift curve of the corresponding gear in the power shift strategy. In the present invention, if the economic shift strategy and the power shift strategy are two-dimensional relationship curves, the generated current shift strategy curve is also a two-dimensional relationship curve of vehicle speed and throttle depth. If the economic shift strategy and the power shift strategy are three-parameter relationship curves, the generated shift strategy curve is also a three-parameter relationship curve of vehicle speed, throttle depth, and acceleration. The shift strategy curve also includes an upshift curve and a downshift curve.

[0044] Specifically, set A = D M _n(V) represents the shift curve of the nth gear in the real-time shift strategy curve generated under the current terrain M, and the following expression can be obtained:

[0045] V = D -1 M _n (A) = (1 - K)G -1 n(A) + KF -1 n(A) (1)

[0046] This expression indicates that when the throttle is at A, the speed value of the shift strategy curve is the interpolation of two curves (the economy shift strategy and the power shift strategy) with a ratio of k.

[0047] Among them, A = Gn(V) represents the shift curve of the nth gear in the economy shift strategy, and G -1 n(A) represents the inverse function of Gn(V); A = Fn(V) represents the shift curve of the nth gear in the power shift strategy, and F -1 n(A) represents the inverse function of Fn(V); D -1 M _n(A) represents the inverse function of D M _n(V), where n = 1, 2,..., N, N is the total number of gears of the transmission, A is the throttle depth, and V is the vehicle speed.

[0048] Step 3) The shift controller controls the transmission to shift gears according to the current shift strategy curve. This step specifically includes the following:

[0049] Step 3.1) Obtain the current gear of the vehicle, and obtain the upshift curve and downshift curve of the current gear according to the current shift strategy curve.

[0050] Step 3.2) According to the current throttle depth of the vehicle, combine the expression (1) of the shift curve of the nth gear of the current shift strategy curve to calculate the vehicle speeds of the upshift curve and the downshift curve respectively; that is, substitute the current throttle and the upshift curve of the current gear into the expression (1) above to obtain the vehicle speed of the upshift curve. Substitute the current throttle and the downshift curve of the current gear into the expression (2) above to obtain the vehicle speed of the downshift curve.

[0051] Step 3.3) Compare the current vehicle speed of the vehicle with the calculated vehicle speeds of the upshift curve and the downshift curve, and control whether the transmission shifts gears according to the comparison result.

[0052] Specifically, first judge whether the current vehicle speed is greater than the vehicle speed of the upshift curve. If so, control the transmission to upshift; if not, then judge whether it is less than the vehicle speed of the downshift curve. If so, control the transmission to downshift, and if not, keep the current gear.

[0053] The present invention also proposes a vehicle dynamic shift control system based on terrain, including a shift controller and a transmission. The shift controller is preset with an economy shift strategy and a power shift strategy. It also includes an electronic horizon module for obtaining the current terrain information when the vehicle is driving; the shift controller performs dynamic interpolation fusion according to the current terrain information, the economy shift strategy and the power shift strategy to generate the current shift strategy curve, and controls the transmission to shift gears according to the current shift strategy curve.

[0054] In the present invention, the shift controller is one or more microprocessors operating according to a preset program. The shift controller can receive the vehicle speed, the throttle depth from the accelerator pedal, and the current terrain information from the electronic horizon module through the CAN bus or the Ethernet bus. The transmission is connected to the shift controller. The input torque of the transmission comes from the torque output by the engine, and controls the vehicle to travel in a selected specific gear according to the command of the shift controller to output driving torque to the drive wheels.

[0055] The shift controller of the present invention is provided with a gear shift module and a shift strategy curve generation module. The shift strategy curve generation module performs dynamic interpolation fusion according to the current terrain information, the economic shift strategy, and the power shift strategy to generate the current shift strategy curve. The gear shift module controls the gear shift of the transmission according to the current shift strategy curve.

[0056] In the present invention, for the continuously changing geographical slope of ordinary roads, a pre-stored fixed upshift and downshift strategy is adopted, and a method of intermediate interpolation transformation is used to generate a continuously changing shift strategy curve corresponding to the external slope in real time, so that the vehicle has a wider adaptability to different terrain and topography, and has both power performance and economy.

[0057] The above is only the specific implementation manner of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantive modification made to the present invention using this concept shall fall within the scope of infringement of the protection scope of the present invention.

Claims

1. A terrain-based vehicle dynamic shift control method, which pre-sets an economic shift strategy and a power shift strategy, is characterized in that Including the following steps: Step 1): When the vehicle is running, obtain the current terrain information of the vehicle; Step 2): The shift controller performs dynamic interpolation fusion according to the current terrain information, the economy shift strategy and the power shift strategy to generate the current shift strategy curve; Step 3): The shift controller controls the gearshift of the gearbox according to the current shift strategy curve.

2. The vehicle dynamic shift control method based on terrain according to claim 1, characterized in that: The specific content of step 2) includes: Step 2.1): Calculate the proportional coefficient of the interpolation fusion according to the current terrain information; Step 2.2): Generate the current shift strategy curve according to the proportional coefficient of the interpolation fusion, the shift curve of the corresponding gear in the economy shift strategy and the shift curve of the corresponding gear in the power shift strategy.

3. The vehicle dynamic shift control method based on terrain according to claim 2, wherein: Preset the maximum downhill value M1 corresponding to the economy strategy curve and the maximum uphill value M2 corresponding to the power strategy curve. The proportional coefficient of the interpolation fusion is K = |M - M1| / |M2 - M1|, where M is the slope value of the current terrain information.

4. A vehicle dynamic shift control method based on terrain according to claim 1 or 3, characterized in that: Let A = Gn(V) represent the shift curve of the nth gear in the economy shift strategy, A = Fn(V) represent the shift curve of the nth gear in the power shift strategy, and A = D M _n(V) represents the shift curve of the nth gear in the shift strategy curve generated under the slope value M of the current terrain information, and the expression is as follows: V = D -1 M _n(A) = (1 - K)G -1 n(A) + KF -1 n(A) (1) F -1 n(A) represents the inverse function of Fn(V); D -1 M _n(A) represents D M _n(V)'s inverse function, where n = 1, 2,..., N, N is the total number of gears of the gearbox, A is the throttle depth, and V is the vehicle speed of the vehicle.

5. The vehicle dynamic shift control method based on terrain according to claim 4, characterized in that: The specific content of step 3) includes the following: Step 3.1): Obtain the current gear of the vehicle, and obtain the upshift curve and downshift curve of the current gear according to the current shift strategy curve; Step 3.2): According to the current throttle depth of the vehicle, calculate the vehicle speeds of the upshift curve and the downshift curve respectively by combining the expression (1) of the shift curve of the nth gear in the shift strategy curve; Step 3.3): Compare the current vehicle speed of the vehicle with the vehicle speeds of the calculated upshift curve and downshift curve, and control whether the gearbox shifts gears according to the comparison result.

6. The vehicle dynamic shift control method based on terrain according to claim 5, wherein: In step 3.3), first judge whether the current vehicle speed is greater than the vehicle speed of the upshift curve. If so, control the gearbox to upshift; if not, then judge whether it is less than the vehicle speed of the downshift curve. If so, control the gearbox to downshift. If not, keep the current gear.

7. A vehicle dynamic shift control method based on terrain according to claim 1, characterized in that: The shift curves of each gear of the economy shift strategy and the shift curves of each gear of the power shift strategy are respectively two-dimensional relationship curves of vehicle speed and throttle depth.

8. The vehicle dynamic shift control method based on terrain according to claim 1, characterized in that: In step 1), the current terrain information is obtained through an electronic horizon.

9. A terrain-based vehicle dynamic shift control system, including a shift controller and a gearbox. An economy shift strategy and a power shift strategy are preset in the shift controller, and it is characterized in that: It also includes an electronic horizon module, which is used to obtain the current terrain information of the vehicle when the vehicle is running; the shift controller performs dynamic interpolation fusion according to the current terrain information, the economy shift strategy and the power shift strategy to generate the current shift strategy curve, and controls the gearshift of the gearbox according to the current shift strategy curve.

10. The vehicle dynamic shift control system based on terrain according to claim 9, characterized in that: The shift controller further includes a gearshift module and a shift strategy curve generation module; the shift strategy curve generation module performs dynamic interpolation fusion according to the current terrain information, the economy shift strategy and the power shift strategy to generate the current shift strategy curve; the gearshift module controls the gearshift of the gearbox according to the current shift strategy curve.

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