A control method and system for the shifting process of a two-state logic automatic transmission

Abstract

The present invention relates to the technical field of automatic transmissions, and discloses a control method and system for the shifting process of a two-state logic automatic transmission. The control method first collects parameter signals of the automatic transmission; according to the collected parameter signals, pre-processing before the shifting process of the automatic transmission is performed to determine the rotational speed change rate and the gear ratio step; according to the gear ratio step and the input shaft rotational speed change rate, the clutch switching mode is determined; according to the determined clutch control method, the shifting process of the automatic transmission is completed. The present invention can improve the shifting quality of vehicles equipped with two-state logic automatic transmissions.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic transmissions, and more specifically, to a method and system for controlling the shifting process of a two-state logic automatic transmission. Background Art

[0002] The double internal meshing planetary gear mechanism is a new type of planetary gear mechanism that has emerged in recent years. An automatic transmission composed of this planetary gear mechanism is called a two-state logic automatic transmission. This automatic transmission has the advantages of a simple shifting process and a large number of gears, greatly improving the power performance, economy, and comfort of vehicles equipped with this type of automatic transmission.

[0003] To improve the transmission efficiency of the equipped vehicle, the number of gears of the automatic transmission is increasing. However, due to space structure and size limitations, the current automatic transmission has a maximum of 16 gears. The two-state logic automatic transmission uses a new type of gear mechanism, breaking through the structural and space limitations and being able to achieve 32-speed transmission (such as the two-state logic automatic transmission disclosed in an automatic planetary transmission with 32 gears, application number 201811444529.7), greatly improving the transmission efficiency. However, with the increase in the number of gears, the shifting control method based on transmission will become more complex, increasing the shifting time and weakening the shifting response characteristics. Therefore, it is necessary to develop a shifting process control method suitable for this two-state logic automatic transmission to improve the shifting quality of the automatic transmission. Summary of the Invention

[0004] In view of this, the present invention provides a method for controlling the shifting process of a two-state logic automatic transmission, which can improve the shifting quality of vehicles equipped with a two-state logic automatic transmission.

[0005] The technical solution adopted by the present invention is as follows: A method for controlling the shifting process of a two-state logic automatic transmission, and the specific steps of this control method are as follows:

[0006] First, collect the parameter signals of the automatic transmission to determine the input shaft speed change rate and the gear ratio step.

[0007] Then, determine the clutch switching mode according to the gear ratio step, the input shaft speed change rate, and the number of shifting elements.

[0008] Finally, complete the shifting process of the automatic transmission according to the determined clutch switching mode.

[0009] As a preferred embodiment of the present invention: The parameter signals include the input shaft speed, the target gear, the actual gear, and the input shaft torque.

[0010] As a preferred embodiment of the present invention: The determination of the clutch switching mode is specifically as follows:

[0011] Compare the calculated change rate of the input shaft speed with the set threshold values, where the threshold values include a negative threshold and a positive threshold, and determine whether the change rate of the input shaft speed is between the set negative threshold and positive threshold;

[0012] Based on the target gear and the actual gear, determine whether an upshift process or a downshift process is required:

[0013] If an upshift process is required, calculate the upshift gear ratio and determine whether it is a two-element upshift: If it is a two-element upshift, further determine the clutch switching mode based on the calculated upshift gear ratio and the change rate of the input shaft speed: When the upshift gear ratio is greater than or equal to the set upshift gear ratio threshold and the change rate of the input shaft speed is between the set negative threshold and positive threshold, perform fast-switch control on the clutch; otherwise, perform oil-filled slip control on the clutch control; If it is not a two-element upshift, perform oil-filled slip control on the clutch;

[0014] If a downshift process is required, calculate the downshift gear ratio and determine whether it is a two-element downshift. If it is a two-element downshift, further determine the clutch switching mode based on the calculated upshift gear ratio and the change rate of the input shaft speed: When the downshift gear ratio is less than or equal to the set downshift gear ratio threshold and the change rate of the input shaft speed is between the set negative threshold and positive threshold, perform fast-switch control on the clutch control; otherwise, perform oil-filled slip control on the clutch; If it is not a two-element downshift, perform oil-filled slip control on the clutch.

[0015] As a preferred embodiment of the present invention: When performing oil-filled slip control on the clutch, determine the control pressure according to the input shaft torque and perform pressure correction through the change rate of the input shaft speed.

[0016] As a preferred embodiment of the present invention: The upshift gear ratio threshold is 0.8; the downshift gear ratio threshold is 1.2.

[0017] In addition, the present invention provides a shift process control system for a two-state logic automatic transmission, and the control system includes:

[0018] A signal acquisition module: used to acquire parameter signals of the automatic transmission;

[0019] A pre-shift process module: used to perform pre-shift process of the automatic transmission according to the parameter signals acquired by the signal acquisition module, and the pre-shift process includes: determining the change rate of speed, the gear ratio, and the number of shift elements;

[0020] A control mode determination module: used to determine the clutch switching mode according to the gear ratio, the change rate of the input shaft speed, and the number of shift elements determined by the pre-shift process module;

[0021] Shift control module: used to determine the clutch control method determined by the module according to the control method, and complete the shift process of the automatic transmission.

[0022] Beneficial effects:

[0023] (1) The present invention aims at the shift time and control quality of a two-state logic automatic transmission, determines the switching mode of the clutch during the shift process, and has great progressive significance for improving the control quality of the two-state logic automatic transmission; this method is applicable to automatic transmission vehicles with multiple gears and multiple-element shifts.

[0024] (2) The control method of the present invention uses the input shaft speed change rate, shift ratio, and number of shift elements as criteria to determine the clutch switching mode. When the set requirements are met, fast switch control is adopted for the clutch, which can effectively improve the shift time.

[0025] (3) When adopting oil filling and slip grinding control for the clutch, the control pressure is determined according to the input shaft torque and the pressure is corrected through the input shaft speed change rate, which can ensure the shift quality. Description of the drawings

[0026] Figure 1 It is a flowchart of the control method for the shift process of the two-state logic automatic transmission of the present invention. Specific implementation manners

[0027] The following further describes the present invention in detail with reference to the drawings and embodiments.

[0028] Embodiment 1:

[0029] This embodiment provides a control method for the shift process of a two-state logic automatic transmission. This control method is applicable to the shift control of the thirty-two-speed automatic planetary transmission disclosed in the application number 201811444529.7; adopting this shift process control method can improve the shift quality of this two-state logic automatic transmission.

[0030] As Figure 1 shown, the specific steps of this control method are as follows:

[0031] Step S1: Collect the parameter signals of the automatic transmission:

[0032] Specifically, the collected parameter signals include the input shaft speed, target gear, actual gear, and input shaft torque of the two-state logic automatic transmission.

[0033] Step S2: According to the parameter signals collected in step S1, perform pre-processing before the shift process of the automatic transmission to determine the speed change rate and gear ratio; the gear ratio refers to the ratio of the target gear transmission ratio to the actual gear transmission ratio;

[0034] The pre - processing before the gear - shifting process is specifically as follows:

[0035] According to the input shaft speed signal, calculate the change rate of the input shaft speed, where the change rate of the input shaft speed is: (input shaft speed at the current moment - input shaft speed at the previous moment) / sampling time;

[0036] Then compare the calculated change rate of the input shaft speed with the set threshold value, and thus divide the change rate of the input shaft speed into three types: large negative, medium, and large positive; specifically, the set threshold values include a negative threshold value and a positive threshold value. When the calculated change rate of the input shaft speed is negative and its absolute value is greater than the absolute value of the negative threshold value, it is considered that the change rate of the input shaft speed is large negative. When the calculated change rate of the input shaft speed is greater than the positive threshold value, it is considered that the change rate of the input shaft speed is large positive. Otherwise, it is considered that the change rate of the input shaft speed is medium; that is, judge whether the change rate of the input shaft speed is between the set negative threshold value and positive threshold value.

[0037] According to the target gear and the actual gear, judge whether to perform an up - shift process or a down - shift process:

[0038] If an up - shift process is required, calculate the up - shift step ratio (target gear ratio / actual gear ratio), and judge whether it is a two - element up - shift (determined by the internal structure of the two - state logic automatic transmission. In the gear - shifting process, it is necessary to control several clutches. If two clutches are controlled, it is a two - element shift. If the number of clutches to be controlled in the gear - shifting process exceeds two, it is a multi - element shift); then enter step S3 for up - shift control;

[0039] If a down - shift process is required, calculate the down - shift step ratio, and judge whether it is a two - element down - shift, and then enter step S4 for down - shift control.

[0040] Step S3: Up - shift process control:

[0041] If it is a two - element up - shift, further determine the clutch switching method based on the up - shift step ratio calculated in step 2 and the change rate of the input shaft speed: When the up - shift step ratio is greater than or equal to the set up - shift step ratio threshold value (in this example, the up - shift step ratio threshold value is 0.8), and the change rate of the input shaft speed is medium, perform fast - switch control on the clutch (that is, quickly fill the clutch with oil to shorten the gear - shifting time). Otherwise, perform oil - filling and slip - grinding control on the clutch (that is, control the clutch through slip - grinding to reduce the gear - shifting impact).

[0042] If it is not a two - element up - shift, perform oil - filling and slip - grinding control on the clutch.

[0043] When performing oil - filling and slip - grinding control on the clutch, determine the control pressure according to the input shaft torque and perform pressure correction through the change rate of the input shaft speed.

[0044] Thus, the up - shift control is completed.

[0045] Step S4: Downshift process control:

[0046] If it is a two-component downshift, further determine the clutch switching mode based on the downshift ratio and the input shaft speed change rate calculated in Step 2: When the downshift ratio is less than or equal to the set downshift ratio threshold (in this example, the downshift ratio threshold is 1.2), and the input shaft speed change rate is medium, fast switch control is adopted for clutch control; otherwise, oil filling and slip control is adopted for the clutch.

[0047] If it is not a two-component downshift, oil filling and slip control is adopted for the clutch.

[0048] Thus, the downshift control is completed.

[0049] Embodiment 2:

[0050] This embodiment also provides a shift process control system for a two-state logic automatic transmission, including:

[0051] Signal acquisition module: used to acquire the parameter signals of the automatic transmission;

[0052] Pre-shift process module: used to perform pre-shift process of the automatic transmission according to the parameter signals acquired by the signal acquisition module, and determine the speed change rate, shift ratio, and number of shift elements;

[0053] Control mode determination module: used to determine the clutch switching mode according to the shift ratio, input shaft speed change rate, and number of shift elements determined by the pre-shift process module;

[0054] Shift control module: used to complete the shift process of the automatic transmission according to the clutch control method determined by the control mode determination module.

[0055] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A control method for the shifting process of a two-state logic automatic transmission, characterized in that: The specific steps of the control method are as follows: Collect parameter signals of the automatic transmission to determine the input shaft speed change rate and gear ratio step; Determine the clutch switching mode according to the gear ratio step, input shaft speed change rate, and number of shift elements; Complete the gear shifting process of the automatic transmission according to the determined clutch switching mode; The parameter signals include input shaft speed, target gear, actual gear, and input shaft torque; The determination of the clutch switching mode is specifically as follows: Compare the calculated input shaft speed change rate with the set thresholds. The thresholds include a negative threshold and a positive threshold, and determine whether the input shaft speed change rate is between the set negative threshold and positive threshold; Judge whether an upshift process or a downshift process is required according to the target gear and the actual gear: If an upshift process is required, calculate the upshift ratio step and determine whether it is a two-element upshift: If it is a two-element upshift, further determine the clutch switching mode based on the calculated upshift ratio step and the input shaft speed change rate: When the upshift ratio step is greater than or equal to the set upshift ratio step threshold and the input shaft speed change rate is between the set negative threshold and positive threshold, use fast-switch control for the clutch; otherwise, use oil-filled slip control for the clutch control; If it is not a two-element upshift, use oil-filled slip control for the clutch; If a downshift process is required, calculate the downshift ratio step and determine whether it is a two-element downshift. If it is a two-element downshift, further determine the clutch switching mode based on the calculated upshift ratio step and the input shaft speed change rate: When the downshift ratio step is less than or equal to the set downshift ratio step threshold and the input shaft speed change rate is between the set negative threshold and positive threshold, use fast-switch control for the clutch control; otherwise, use oil-filled slip control for the clutch; If it is not a two-element downshift, use oil-filled slip control for the clutch.

2. The method for controlling the shifting process of the two-state logic automatic transmission according to claim 1, wherein: When using oil-filled slip control for the clutch, determine the control pressure according to the input shaft torque and perform pressure correction through the input shaft speed change rate.

3. The method for controlling the shift process of the two-state logic automatic transmission according to claim 1 or 2, characterized in that: The upshift ratio step threshold is 0.8; the downshift ratio step threshold is 1.

2.

4. A shift process control system for a two-state logic automatic transmission, characterized in that: Based on the control method for the gear shifting process of the bistate logic automatic transmission according to any one of claims 1 to 3: The control system includes: A signal acquisition module: used to collect parameter signals of the automatic transmission; A pre-shifting process module: used to perform pre-shifting process of the automatic transmission according to the parameter signals collected by the signal acquisition module. The pre-shifting process includes: determining the speed change rate, gear ratio step, and number of shift elements; A control mode determination module: used to determine the clutch switching mode according to the gear ratio step, input shaft speed change rate, and number of shift elements determined by the pre-shifting process module; A gear shifting control module: used to complete the gear shifting process of the automatic transmission according to the clutch control method determined by the control mode determination module.

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