AMT-based commercial vehicle national sixth NGE ejection starting control system and method
By designing a commercial vehicle National VI natural gas engine ejection start control system based on AMT, using the control module connected by hard wire and CAN wire, the precise control of engine speed and torque is achieved, which solves the problem of delay in starting response of natural gas engines in commercial vehicles, and significantly improves the starting speed and response speed.
Patent Information
- Application Number
- CN202510084632.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-05-06
AI Technical Summary
When the existing commercial vehicle natural gas engines match AMT, the starting response delay and slow starting speed are difficult to meet the needs of users, especially in harsh transportation conditions.
A commercial vehicle National VI natural gas engine ejection start control system is designed based on AMT. The system includes a natural gas engine ECU, AMT's TCU and AMT shift handle control module. It can achieve precise control of the engine speed and torque through hard wire and CAN wire connection, quickly increase the engine speed and control the clutch to quickly combine to achieve ejection start.
It effectively overcomes the torque delay of natural gas engines, significantly improves the starting speed, reduces the starting torque response delay time, and is close to the response speed of diesel engines, meeting the starting needs of commercial vehicles under harsh working conditions.
Smart Images
Figure CN119928809A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of engines and relates to a natural gas engine, and in particular to a National VI NGE launch control system and method for commercial vehicles based on AMT. Background Art
[0002] In recent years, the demand for commercial vehicles equipped with natural gas and AMT (Automated Mechanical Transmission) has skyrocketed. Due to the combustion characteristics of natural gas itself, such as small compression ratio, low calorific value, slow combustion speed and other factors, the transient torque response of NGE (Natural Gas Engine) is slower than that of diesel engine.
[0004] The hysteresis of torque response causes some users in special working conditions to report problems such as slow starting speed and slow starting response. Especially for users in some harsh transportation conditions such as commercial vehicles hauling coal, there is an urgent need to solve these problems. Summary of the invention
[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a National VI NGE launch control system and method for commercial vehicles based on AMT, so as to solve the technical problems of delayed starting response and slow starting speed of existing commercial vehicle AMT matched with natural gas engine.
[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:
[0007] A commercial vehicle National VI natural gas engine launch control system based on AMT, the system includes a natural gas engine ECU, an AMT TCU and an AMT shift handle control module respectively connected to CAN lines; the natural gas engine ECU is connected to the accelerator pedal through a hard line; the AMT TCU is connected to the clutch through a hard line.
[0008] It also includes a launch control multimedia switch connected to the CAN line.
[0009] Also included is a launch control hardwire switch that is hardwired to the AMT's TCU.
[0010] The launch switch signal is transmitted to the AMT's TCU through the AMT shift handle control module, the launch multimedia switch and the launch hard-line switch.
[0011] The present invention also protects a method for launching a National VI natural gas engine for a commercial vehicle based on AMT, which adopts the National VI natural gas engine launch control system for a commercial vehicle based on AMT as described above.
[0012] The method comprises the following steps:
[0013] In the first step, after the driver inputs the launch start switch signal to the AMT's TCU, the AMT's TCU controls the speed and torque of the natural gas engine through the TSC message, increasing the speed of the natural gas engine from idle speed to high speed.
[0014] In the second step, when the engine speed reaches a high speed and stabilizes, the driver shifts gears and then steps on the accelerator pedal. The accelerator pedal signal is input to the engine ECU through a hard line. The engine ECU simultaneously inputs the accelerator pedal signal to the AMT's TCU through the TSC message. After receiving the accelerator pedal signal input, the AMT's TCU controls the clutch in the AMT to engage quickly.
[0015] The third step is that during the rapid engagement of the clutch, the TCU continuously increases the target speed of the natural gas engine from the initial high speed to the engine speed corresponding to the maximum power point of the natural gas engine. The torque of the natural gas engine is steadily and rapidly increased through the torque control of the AMT's TCU. With the engagement of the clutch and the continuous increase in the torque of the natural gas engine, the vehicle enters the launch start process and the clutch enters the semi-clutch sliding process.
[0016] The fourth step is that as the vehicle speed increases after the launch control, the speed of the natural gas engine and the input shaft speed of the AMT will eventually be synchronized, the entire launch control process is completed, and the vehicle completes the launch control.
[0017] The idle speed is 600 rpm; the high speed is greater than or equal to 1000 rpm.
[0018] After the speed of the natural gas engine increases from the idle speed of 600rpm to the high speed of 1000rpm, the starting torque response delay of the natural gas engine is 50ms to 70ms.
[0019] Compared with the prior art, the present invention has the following technical effects:
[0020] (I) The present invention can effectively overcome the torque delay of the natural gas engine and improve the starting speed. The AMT increases the engine idle speed by controlling the engine speed and torque. As the speed increases, the torque delay of the natural gas engine will gradually decrease. After the engine reaches the target speed, the AMT quickly engages the clutch to achieve the effect and purpose of launching the vehicle.
[0021] (II) The present invention provides an effective and fast commercial vehicle ejection start solution based on the use and performance characteristics of natural gas engines and AMT to meet the needs of domestic heavy truck drivers. Unlike small passenger cars, small passenger cars, whether equipped with gasoline engines or diesel engines, have a relatively small weight and a fully loaded total mass of generally less than 5 tons. In addition, small cars are mainly AT (Automatic Transmission). Large heavy commercial trucks weigh 40 to 50 tons when fully loaded. The ejection start control is difficult, especially for the combined control of the dry clutch. It is necessary to have a fast ejection start and ensure a certain degree of comfort. Compared with the AT torque converter, it has a natural disadvantage and requires a lot of calculation control to meet the final user's use needs.
[0022] (III) In the present invention, the starting torque response of the natural gas engine for commercial vehicles is approximately between 250ms and 300ms, and after the idle speed of the natural gas engine is increased from 600rpm to 1000rpm, the starting torque response delay of the natural gas engine is between 50ms and 70ms, which has greatly improved the response speed of the natural gas engine, approaching the level of a diesel engine, and preparing the torque response for launch start. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a launch control system for the National VI natural gas engine of commercial vehicles based on AMT.
[0024] Figure 2 Comparison of TSC torque response delay of electric motors, diesel engines, and gas engines.
[0025] Figure 3 This is a schematic diagram of the control principle of the ejection start theory.
[0026] Figure 4 This is a schematic diagram of the calculation and control logic of the ejection start.
[0027] Figure 5 This is a diagram showing the control effect of the launch start real vehicle test machine.
[0028] The meanings of the numbers in the figure are: 1-natural gas engine ECU, 2-AMT TCU, 3-AMT shift handle control module, 4-CAN line, 5-hard line, 6-accelerator pedal, 7-clutch, 8-launch start multimedia switch, 9-launch start hard line switch.
[0029] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION
[0030] It should be noted that, unless otherwise specified, all modules, devices and components in the present invention are modules, devices and components known in the prior art. For example, the AMT shift handle control module is an AMT shift handle control module known in the art.
[0031] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.
[0032] Embodiment 1:
[0033] This embodiment provides a launch control system for a National VI natural gas engine of a commercial vehicle based on AMT. Figure 1 As shown, the system includes a natural gas engine ECU (Electronic Control Unit) 1, an AMT TCU (Telematics Control Unit) 2 and an AMT shift handle control module 3, which are respectively connected to a CAN (Controller Area Network) line 4; the natural gas engine ECU1 is connected to an accelerator pedal 6 via a hard line 5; and the AMT TCU2 is connected to a clutch 7 via a hard line 5.
[0034] like Figure 1 As shown, a launch control multimedia switch 8 connected to the CAN line 4 is also included.
[0035] like Figure 1 As shown, it also includes a launch start hardline switch 9 connected to the TCU 2 of the AMT through a hardline 5.
[0036] like Figure 1 As shown, the launch start switch signal is transmitted to the TCU2 of the AMT through the AMT shift handle control module 3, the launch start multimedia switch 8 and the launch start hard-line switch 9 respectively.
[0037] In this embodiment, the driver first inputs the launch switch signal according to the use requirements. There are many conditions where commercial vehicles need to use the launch switch, such as the large resistance start condition. According to the actual application requirements of the current domestic market, three types of launch switch signal inputs are planned. Drivers and vehicle manufacturers can choose to use different switch signal inputs according to their respective vehicle model requirements.
[0038] There are three types of launch switch signals. The first is that the panel switch is hard-wired to the TCU to input the simulated launch switch signal; the second is that the multimedia touch screen panel inputs the simulated launch switch signal to the TCU through a message; the third is the control module integrated into the AMT's shift handle to simulate the launch switch signal. The current mainstream handle control modes of domestic commercial vehicle AMT include power mode, economy mode, escape mode, off-road mode, etc.
[0039] In this embodiment, the natural gas engine is a National VI natural gas engine.
[0040] Embodiment 2:
[0041] This embodiment provides a method for launching a National VI natural gas engine for a commercial vehicle based on an AMT. The method adopts the launch control system for a National VI natural gas engine for a commercial vehicle based on an AMT given in Example 1.
[0042] like Figure 3 As shown, the method comprises the following steps:
[0043] In the first step, after the driver inputs the launch switch signal to the AMT's TCU2, the AMT's TCU2 controls the speed and torque of the natural gas engine through the TSC (Torque / Speed Control) message, increasing the speed of the natural gas engine from idle speed to high speed.
[0044] The idle speed is 600 rpm; the high speed is greater than or equal to 1000 rpm.
[0045] Figure 2 Comparison of TSC torque response delay of electric motor, diesel engine and gas engine. Figure 2 In the figure: TSC1 is the required torque of the gearbox; Tq1 is the actual response torque of the motor; Tq2 is the actual response torque of the diesel engine; Tq3 is the actual response torque of the natural gas engine; △T1 is the torque response delay time of the motor; △T2 is the torque response delay time of the diesel engine; △T3 is the torque response delay time of the natural gas engine.
[0046] The control difficulty of the present invention lies in overcoming and controlling the torque response delay of the natural gas engine. Figure 2 It can be seen that the torque response delay △T1 of the motor is less than 10ms, the torque response delay △T2 of the diesel engine is about 20ms, and the torque response delay △T3 of the natural gas engine is 300ms due to the combustion characteristics of natural gas. The torque response delay of the natural gas engine is much greater than the torque characteristics of the motor and diesel engine.
[0047] In this embodiment, as shown in Table 1, after actual tests, for commercial vehicle natural gas engines, 1000 rpm is the minimum speed that can overcome the torque delay of the natural gas engine. During the speed increase process, the TCU2 of the AMT must ensure a stable and accurate high-speed control target of the engine. If the speed is unstable, it will lead to subsequent starting failures and insufficient starting ability.
[0048] Table 1 Torque response delay time corresponding to different natural gas engine speeds and torques
[0049]
[0050]
[0051] In Table 1, Tq is the actual engine torque percentage; N1 is the actual engine speed; and MAP1 corresponds to the torque response delay time.
[0052] In this embodiment, the starting torque response delay of the commercial vehicle diesel engine is approximately between 10ms and 20ms, and the motor response speed is less than 10ms. The starting torque response of the commercial vehicle natural gas engine is approximately between 250ms and 300ms. After the speed of the natural gas engine is increased from the idle speed of 600rpm to the high speed of 1000rpm, the starting torque response delay of the natural gas engine is 50ms to 70ms, which has greatly improved the response speed of the natural gas engine, approaching the level of the diesel engine, and preparing the torque response for the launch start.
[0053] In this embodiment, the torque delay of the natural gas engine can be effectively solved by increasing the engine idle speed before the driver shifts gears and steps on the accelerator. If the engine speed is increased after the gear is shifted and the accelerator is stepped on, the natural gas engine needs to increase the speed from 600rpm and cannot overcome the hysteresis caused by the torque response, and the effect of launching the vehicle when the accelerator is stepped on cannot be achieved. Increasing the engine idle speed is an effective method to speed up the torque response speed of the natural gas engine. After overcoming the slow torque response characteristics of the natural gas, the full power of the engine can be finally exerted through the control of the clutch 7 and the engine torque to achieve the strongest launch effect.
[0054] In the second step, when the engine speed increases to a high speed and stabilizes, the driver shifts gears, and then steps on the accelerator pedal 6. The accelerator pedal 6 signal is input to the engine ECU through a hard line, and the engine ECU simultaneously inputs the accelerator pedal 6 signal to the AMT's TCU2 through the TSC message. After receiving the input requirement of the accelerator pedal 6 signal, the AMT's TCU2 controls the clutch 7 in the AMT to engage quickly.
[0055] In the third step, during the rapid engagement of clutch 7, TCU continuously increases the target speed of the natural gas engine from the high speed at the beginning to the engine speed corresponding to the maximum power point of the natural gas engine, ensuring that the maximum power of the natural gas engine can be exerted under extreme working conditions to complete the launch start. The torque of the natural gas engine is steadily and continuously increased rapidly through the torque control of TCU2 of AMT. With the engagement of clutch 7 and the continuous increase of the torque of the natural gas engine, the vehicle enters the launch start process, and clutch 7 enters the semi-clutch sliding process.
[0056] As the vehicle speed increases after the launch control, the speed of the natural gas engine and the input shaft speed of the AMT will eventually be synchronized, the entire launch control process is completed, and the vehicle completes the launch control.
[0057] In this embodiment, since the clutch 7 is engaged at a fast speed during the slipping process, care should be taken to prevent the engine from being stalled due to a slow response of the transient torque.
[0058] Further, such as Figure 4 As shown, the calculation method and control logic of this method are as follows:
[0059] Figure 4 , △N1 is the first target speed difference; △N2 is the second target speed difference; ST is the launch start state, ST=0 indicates static; ST=1 indicates dynamic racing start; ST=2 indicates racing start is completed.
[0060] When ST=0, it indicates that the vehicle is stationary at this time, and the driver has not stepped on the accelerator pedal 6. According to the actual torque response time t_Tq of the natural gas engine and the torque time t_TSC1 of the natural gas engine, the torque response delay time △T of the natural gas engine is calculated, as shown in Table 2. According to △T, MAP2 is calibrated to obtain the static engine target speed N2. The static target speed difference △N1 of N2-N1 is used to perform the speed closed-loop control of PID1. PID1 is the no-load PID (Proportion Integration Differentiation) control parameter when the clutch 7 is not engaged. The engine required torque TSC1 (Torque / Speed Control 1) required to achieve the target speed N2 is obtained. The engine is controlled by TSC1 to jet to finally stabilize the actual engine speed N1 at the static target engine speed N2, so as to reduce the torque response delay when the clutch 7 is subsequently engaged. According to the MAP1 measured natural gas engine torque response delay data in Table 1, it can be seen that the lower the speed and the lower the torque, the greater the torque response delay of the natural gas engine. If a smaller engine torque response delay is required, a higher engine static target speed N2 is required.
[0061] Table 2 shows the stationary target engine speed MAP2 corresponding to different torque response delay times
[0062] △T 400ms 300ms 200ms 100ms 50ms 10ms N2 1200 1000 900 800 700 600
[0063] In Table 2, ΔT is the torque response delay time, and N2 is the stationary engine target speed.
[0064] When ST=1, it indicates that the vehicle has entered the dynamic state of the driver stepping on the accelerator to start from the static state, as shown in Table 3. At this time, the dynamic engine target speed N3 is obtained by calibrating MAP3 by the opening degree and slope of the accelerator pedal 6. The speed closed-loop control of PID2 is performed through the dynamic target speed difference △N2 of N3-N1. PID2 is the load PID control parameter during the clutch 7 engagement process. The engine demand torque TSC1 required to achieve the target speed N3 is obtained. The engine is controlled by TSC1 to jet to finally stabilize the actual engine speed N1 at the dynamic target engine speed N2 during the slip and engagement process of the clutch 7, completing the torque transmission control of the launch start. When the actual engine speed N1 is equal to the transmission input shaft speed NI, it means that the clutch 7 is synchronized, and ST=2, the entire launch start control is completed.
[0065] Table 3 shows the dynamic target engine speed MAP3 at different throttle openings and different slopes.
[0066]
[0067] In Table 3, AP is the accelerator pedal opening, S is the road slope, and N3 is the dynamic engine target speed.
[0068] As a preferred example of this embodiment, Figure 5 The control test data of the launch control of a 49-ton tractor with a full load is as follows. For a 49-ton load, the time for the launch input shaft speed NI to increase to the normal idle speed of the engine is less than 1.2 seconds, which is much faster than the 2s to 3s of a normal natural gas engine start. The overall starting speed is increased by more than 50%.
Claims
1. A commercial vehicle National VI natural gas engine launch control system based on AMT, the system comprising a natural gas engine ECU (1), an AMT TCU (2) and an AMT shift handle control module (3) respectively connected to a CAN line (4); the natural gas engine ECU (1) is connected to an accelerator pedal (6) via a hard line (5); the AMT TCU (2) is connected to a clutch (7) via a hard line (5); the system is characterized in that: It also includes a launch control multimedia switch (8) connected to the CAN line (4); Also included is a launch control hardwire switch (9) connected to the TCU (2) of the AMT via a hardwire (5); The launch start switch signal is transmitted to the TCU (2) of the AMT through the AMT shift handle control module (3), the launch start multimedia switch (8) and the launch start hard line switch (9).
2. A method for launching a commercial vehicle National VI natural gas engine based on AMT, characterized in that: The method adopts the AMT-based commercial vehicle National VI natural gas engine launch control system as described in claim 1.
3. The AMT-based commercial vehicle National VI natural gas engine launch control method according to claim 2, characterized in that: The method comprises the following steps: In the first step, after the driver inputs the launch switch signal to the AMT TCU (2), the AMT TCU (2) controls the speed and torque of the natural gas engine through the TSC message, thereby increasing the speed of the natural gas engine from the idle speed to the high speed; In the second step, when the engine speed increases to a high speed and stabilizes, the driver performs a gear shifting operation, and then the driver steps on the accelerator pedal (6), and the accelerator pedal (6) signal is input to the engine ECU through a hard line, and the engine ECU simultaneously inputs the accelerator pedal (6) signal to the AMT TCU (2) through a TSC message. After receiving the stepping input requirement of the accelerator pedal (6) signal, the AMT TCU (2) controls the clutch (7) in the AMT to quickly engage; Step 3: During the rapid engagement of the clutch (7), the TCU continuously increases the target speed of the natural gas engine from the initial high speed to the engine speed corresponding to the maximum power point of the natural gas engine. The torque of the natural gas engine is steadily and rapidly increased through the torque control of the TCU (2) of the AMT. As the clutch (7) engages and the torque of the natural gas engine continues to increase, the vehicle enters the launch start process, and the clutch (7) enters the semi-clutch sliding process. The fourth step is that as the vehicle speed increases after the launch control, the speed of the natural gas engine and the input shaft speed of the AMT will eventually be synchronized, the entire launch control process is completed, and the vehicle completes the launch control.
4. The method for launching a commercial vehicle National VI natural gas engine based on AMT as claimed in claim 3, characterized in that: The idle speed is 600 rpm; the high speed is greater than or equal to 1000 rpm.
5. The method for launching a commercial vehicle National VI natural gas engine based on AMT as claimed in claim 4, characterized in that: After the speed of the natural gas engine increases from the idle speed of 600rpm to the high speed of 1000rpm, the starting torque response delay of the natural gas engine is 50ms to 70ms.