A hybrid transmission system suitable for heavy-duty trucks and a control method thereof

Abstract

The application discloses a hybrid power transmission system and a control method suitable for heavy trucks, and relates to the field of automobile gearboxes. The system mainly comprises an engine and a first input assembly: an engine, an engine output shaft, a clutch Y, a first intermediate shaft, a B1 gear of the first intermediate shaft, an A1 gear of the intermediate shaft, a second intermediate shaft, an A2 gear of the intermediate shaft, an A3 gear of the intermediate shaft, an intermediate shaft, a B2 gear of the intermediate shaft, an A3 gear of the intermediate shaft and a B3 gear of the second intermediate shaft; a motor and a second input assembly: a driving motor, a second input shaft, a C1 gear of the second input shaft, a C2 gear of the second input shaft, a high gear of a sub-gearbox, a low gear of the sub-gearbox; a planetary gear assembly: a sun gear, a planet carrier and a ring gear; a clutch E; a clutch R; a clutch T; a brake Q; and a brake W. The hybrid power transmission system suitable for heavy trucks adopts gear transmission, and has high transmission efficiency. The system has different power sources or optimizes the combination of power, thereby improving the use efficiency of power and the performance of the vehicle. In addition, the application also relates to a hybrid power method using the transmission system, which comprises a torque supplementing mode in a gear shifting process and a torque strengthening mode in a reverse gear process. The mode can reduce or even eliminate the jerk of the vehicle caused by power interruption in the gear shifting process and solve the problem of insufficient transmission output torque in the reverse gear process.

Description

Technical Field

[0001] This invention belongs to the field of automotive transmission technology, specifically relating to a hybrid transmission system suitable for heavy-duty trucks. Technical Background

[0002] With energy shortages and environmental pollution becoming increasingly prominent, electric vehicles powered by batteries represent the inevitable trend in automotive reform and replacement. However, for heavy-duty trucks requiring long-distance travel, current battery technology struggles to meet their demands. Therefore, hybrid systems are the best option for trucks in this context, fully utilizing the energy generated by the engine while also satisfying their range requirements. Currently, most trucks worldwide are equipped with transmissions that inevitably experience power interruptions during gear shifts, leading to vehicle jerking, and may encounter insufficient reverse power output in challenging road conditions. Summary of the Invention

[0003] The purpose of this invention is to provide a hybrid power transmission system and its control method suitable for heavy-duty trucks. This transmission system features high power transmission efficiency and diverse transmission routes. Its control method can solve the problems of vehicle jerking during gear shifts and insufficient power during reverse gear.

[0004] The technical solution provided by this invention is as follows:

[0005] This invention provides a hybrid power transmission system suitable for heavy-duty trucks, comprising:

[0006] The engine, which is fixedly connected to the engine output shaft;

[0007] An engine output shaft, which is fixedly connected to the engine;

[0008] The intermediate first shaft is selectively connected to the engine output shaft; the intermediate first shaft B1 gear is fixedly mounted on the intermediate first shaft and meshes with the intermediate shaft A1 gear;

[0009] An intermediate shaft is fixedly mounted with the intermediate shaft A1 gear; and has intermediate shaft A2 gear and intermediate shaft A3 gear loosely fitted; wherein the intermediate shaft A2 gear meshes with the intermediate second shaft B2 gear, and the intermediate shaft A3 gear meshes with the intermediate second shaft B3 gear; an intermediate second shaft is connected to the intermediate first shaft; and has intermediate second shaft B2 gear and intermediate second shaft B3 gear fixedly mounted thereon.

[0010] The intermediate third axis is connected to the intermediate second axis;

[0011] A drive motor, comprising a stator and a rotor; the stator is fixed to the housing of the transmission system;

[0012] The second input shaft is connected to the rotor and is fitted with a second input shaft C1 gear and a second input shaft C2 gear. The planetary gear set includes a sun gear, planet gears, a planet carrier, and a ring gear. The high-gear and low-gear gears of the auxiliary gearbox are fixedly connected to the planet carrier and mesh with the second input shaft C1 gear and the second input shaft C2 gear, respectively. The sun gear is fixed to the intermediate third shaft. The ring gear is selectively connected to the transmission system housing or the planet carrier. The sun gear meshes with the planet gears.

[0013] The fourth axis in the middle is connected to the planetary carrier;

[0014] The output shaft is selectively connected to the gear ring and the intermediate fourth shaft.

[0015] Preferably, the intermediate shaft is selectively connected to the intermediate shaft A2 gear and the intermediate shaft A3 gear via a splined hub and a sliding sleeve E; the second input shaft is selectively connected to the second input shaft C1 gear and the second input shaft C2 gear via a splined hub and a sliding sleeve F.

[0016] Preferably, the clutch housing in the transmission system is connected to the output shaft;

[0017] The clutch R driving end is connected to the gear ring; the clutch T driving end is connected to the intermediate fourth shaft.

[0018] Preferably, in the transmission system, the planetary carrier is connected to the driving end of the brake W, and the driven end of the brake W is connected to the transmission system housing; the ring gear is connected to the driving end of the clutch E, and the driven end of the clutch E is connected to the planetary carrier; the ring gear is connected to the driving end of the brake Q, and the driven end of the brake Q is connected to the transmission system housing. This invention also provides a control method for a hybrid transmission system suitable for heavy-duty trucks. When the hybrid transmission system for heavy-duty trucks is in a shifting gear position, as the clutch used to selectively connect the engine output shaft and the intermediate first shaft gradually disengages, the vehicle's electronic control unit calculates the reduction in transmitted torque based on the change in clutch position. Simultaneously, the motor controls the power input of the drive motor according to the reduced value using a sliding mode control method, thereby reducing or eliminating the impact caused by power interruption during gear shifting.

[0019] The hybrid transmission system for heavy-duty trucks, when in reverse gear, features both an engine-only power output mode and an engine-and-drive-motor combined torque output mode. The decision to engage the drive motor-enhanced torque mode is based on the vehicle's operating conditions and the driver's needs.

[0020] The beneficial effects of this invention are:

[0021] The present invention provides a hybrid transmission system and control method suitable for heavy trucks, which adopts a power hybrid of engine and motor, and can select different power sources or optimize the power combination according to different working conditions and needs, thereby improving the power utilization efficiency and vehicle performance.

[0022] This invention provides a hybrid transmission system and control method suitable for heavy-duty trucks. It employs a multi-stage transmission, including a planetary gear set, multi-gear design, motor, and second input assembly. This allows for the selection of different gears and transmission ratios according to different driving conditions and needs, improving vehicle handling and stability. It also enables power decoupling and redistribution, increasing output torque. While improving system performance and efficiency, it also reduces system complexity and cost. Furthermore, by selecting different clutch engagement methods or control methods, this invention achieves smooth power transmission and stable vehicle operation, improving ride comfort and driving smoothness.

[0023] This invention provides a hybrid transmission system and its control method suitable for heavy-duty trucks, which has broad application and market prospects. Its overall design is scientifically sound, convenient and stable to use, energy-saving, highly efficient, and environmentally friendly. Attached Figure Description

[0024] Figure 1 A simplified structural diagram of a hybrid transmission system suitable for heavy-duty trucks.

[0025] Figure 2 A cross-sectional schematic diagram of a hybrid transmission system suitable for heavy-duty trucks.

[0026] Figure 3 1st gear power transmission route

[0027] Figure 4 2nd gear power transmission route

[0028] Figure 5 3rd gear power transmission route

[0029] Figure 6 4-speed power transmission route

[0030] Figure 7 5-speed power transmission route

[0031] Figure 8 6-speed power transmission route

[0032] Figure 9 7-speed power transmission route

[0033] Figure 10 8-speed power transmission route

[0034] Figure 11 Reverse gear power transmission route

[0035] Figure 12 Reverse 2nd gear power transmission route

[0036] Figure 13 Shift process controller signal transmission process diagram

[0037] Figure 14 Reverse gear torque enhancement controller signal transmission process diagram

[0038] like Figure 1 As shown, this invention provides a hybrid transmission system suitable for heavy-duty trucks, comprising: 1-housing; 2-intermediate shaft A1 gear; 3-intermediate shaft A2 gear; 4-spline hub; 5-sliding sleeve E; 6-intermediate shaft A3 gear; 7-bearing; 8-auxiliary gearbox high-gear; 9-intermediate shaft; 10-bearing; 11-brake Q; 12-brake W; 13-clutch E; 14-gear ring; 15-planetary gear; 16-clutch R; 17-clutch T; 18-clutch housing; 19-bearing; 20-flange; 21-output shaft; 22-intermediate fourth shaft; 23-sun gear; 24-intermediate third shaft; 25-bearing; 26-planetary carrier; 27-auxiliary gearbox low-gear; 28-bearing; 29-coupling; 30-secondary input shaft C2 gear; 31-spline hub; 32-sliding sleeve F. 33-Second input shaft C1 gear; 34-Bearing; 35-Bearing; 36-Intermediate second shaft B3 gear; 37-Second input shaft; 38-Motor stator; 39-Motor rotor; 40-Intermediate second shaft B2 gear; 41-Clutch Y; 42-Bearing; 43-Engine; 44-Engine output shaft; 45-Intermediate first shaft; 46-Intermediate first shaft B1 gear; 47-Intermediate second shaft; 48-Bearing. The hybrid transmission system suitable for heavy trucks mainly consists of the following parts:

[0039] Engine and first transmission assembly: The engine (43) is the power input of the assembly. The driving end of the clutch Y (41) is connected to the engine output shaft (44). The driven end of the clutch Y (41) is connected to the intermediate first shaft (45). The intermediate first shaft B1 gear (46) is fixedly connected to the intermediate first shaft (45). The intermediate first shaft B1 gear (46) meshes with the intermediate shaft A1 gear (2). The intermediate first shaft (45) and the intermediate second shaft (47) are floatingly connected. The intermediate shaft A2 gear (3) and the intermediate shaft A3 gear (6) are loosely mounted on the intermediate shaft (9). The inner spline of the sliding sleeve E (5) can slide on the outer spline of the spline hub (4). The spline hub (4) is fixedly connected to the intermediate shaft (9). The intermediate shaft A2 gear (3) meshes with the intermediate second shaft B2 gear (40). The intermediate shaft A3 gear (6) meshes with the intermediate second shaft B3 gear (36).

[0040] When clutch Y (41) is engaged, engine (43) operates, and power is transmitted from engine (43) to engine output shaft (44). Engine output shaft (44) drives clutch Y (41) to rotate. The driven end of clutch Y (41) drives intermediate first shaft (45) to rotate. Intermediate first shaft (45) drives intermediate first shaft B1 gear (46) to rotate. Intermediate first shaft B1 gear (46) drives intermediate shaft A1 gear (2) to rotate. Intermediate shaft A1 gear (2) drives intermediate shaft (9) to rotate. Splined hub (4) rotates together with intermediate shaft (9). Intermediate second shaft (47) and intermediate third shaft (24) are connected by coupling (29).

[0041] When the sliding sleeve E(5) is in the neutral position, the intermediate shaft A2 gear (3) and intermediate shaft A3 gear (6) rotate freely on the intermediate shaft (9);

[0042] When the sliding sleeve E(5) is in the left position, the power of the splined hub (4) is transmitted to the intermediate shaft A2 gear (3) through the sliding sleeve E(5). The rotation of the intermediate shaft A2 gear (3) drives the intermediate second shaft B2 gear (40) to rotate, and the intermediate second shaft (47) follows the rotation of the intermediate second shaft B2 gear (40).

[0043] When the sliding sleeve E(5) is in the right position, the power of the splined hub (4) is transmitted to the intermediate shaft A3 gear (6) through the sliding sleeve E(5). The rotation of the intermediate shaft A3 gear (6) drives the intermediate second shaft B3 gear (36) to rotate, and the intermediate second shaft (47) follows the rotation of the intermediate second shaft B3 gear (36).

[0044] Motor and Second Input Assembly: The motor is the power input for this assembly. The motor stator (38) is mounted on the housing (1), and the motor rotor (39) is connected to the second input shaft (37). The second input shaft C1 gear (33) and the second input shaft C2 gear (30) are loosely mounted on the second input shaft (37). The splined hub (31) is fixedly mounted on the second input shaft (37), and the internal spline of the sliding sleeve F (32) can slide on the external spline of the splined hub (31). The second input shaft C1 gear (33) meshes with the high-gear gear (8) of the auxiliary gearbox, and the second input shaft C2 gear (30) meshes with the low-gear gear (27) of the auxiliary gearbox.

[0045] The motor rotor (39) drives the second input shaft (37) to rotate, and the second input shaft (37) drives the splined hub (31) to rotate.

[0046] When the sliding sleeve F(32) is in the neutral position, the second input shaft C1 gear (33) and the second input shaft C2 gear (30) rotate freely on the second input shaft (37).

[0047] When the sliding sleeve F(32) is in the left position, the power of the splined hub (31) is transmitted to the second input shaft C1 gear (33) through the sliding sleeve F(32), and the second input shaft C1 gear (33) drives the auxiliary gearbox high gear (8) to rotate.

[0048] When the sliding sleeve F(32) is in the right position, the power of the splined hub (31) is transmitted to the second input shaft C2 gear (30) through the sliding sleeve F(32), and the second input shaft C2 gear (30) drives the auxiliary gearbox low gear (27) to rotate.

[0049] The planetary gear set assembly includes a sun gear (23), planet gears (15), a planet carrier (26), and a ring gear (14); the high-gear gear (8) and the low-gear gear (27) of the auxiliary gear set are fixedly connected to the planet carrier (26) and mesh with the second input shaft C1 gear and the second input shaft C2 gear, respectively; the sun gear (23) is fixedly mounted on the intermediate third shaft (24).

[0050] Planetary gear (15) is loosely fitted on planet carrier (26). Planetary gear (15) meshes with ring gear (14). Ring gear (14) is connected to the driving end of brake Q (11), the driving end of clutch E (13), and the driving end of clutch R (16), respectively. The driven end of clutch E (13) is connected to planet carrier (26). Planet carrier (26) is connected to the driving end of clutch T (17). Brake Q (11) and brake W (12) are fixed on housing (1). Clutch housing (18) is fixedly connected to output shaft (21). Output shaft (21) is connected to flange (20).

[0051] When brake Q (11) is engaged, clutch T (17) is engaged, and brake W (12), clutch E (13), and clutch R (16) are disengaged, the gear ring (14) is fixed to the housing (1) via brake Q (11); power is input from the sun gear (23), transmitted to the planet carrier (26) via planet gear (15), and output from the planet carrier (26). The planet carrier (26) drives the intermediate fourth shaft (22) to rotate, and drives the clutch housing (18) to rotate via clutch T (17). Power is then transmitted from the clutch housing (18) to the flange (20) via the output shaft (21).

[0052] When clutch E(13) is engaged, clutch T(17) is engaged, and brakes Q(11), W(12), and R(16) are disengaged, the ring gear (14) and planetary carrier (26) are locked together by clutch E(13); power is input from the sun gear (23), which puts the planetary gear set in a direct drive state. The planetary carrier (26) and ring gear (14) rotate together and are transmitted to the clutch housing (18) through the intermediate fourth shaft (22) and clutch T(17), and then transmitted to the flange (20) through the output shaft (21).

[0053] When brake W (12) is engaged, clutch R (16) is engaged, and brake Q (11), clutch E (13), and clutch T (17) are disengaged, planet carrier (26) is fixed to housing (1) via brake W (12); power is input from sun gear (23) and transmitted to ring gear (14) via planet gear (15). At this time, the direction of ring gear (14) is opposite to that of sun gear (23). Ring gear (14) drives clutch housing (18) to rotate via clutch R (16). Power is then transmitted from clutch housing (18) to flange (20) via output shaft (21).

[0054] Table 1 Detailed Implementation Plan:

[0055]

[0056] Note: In reverse gear 1, the motor does not output torque; in reverse gear 2, the motor inputs in reverse; in reverse gear 2, the brake W disengages (×).

[0057] "×" separates, "√" combines

[0058] "←" moves left, "→" moves right.

[0059] 1st gear

[0060] Power is transmitted to the transmission system by the engine (43) and the motor rotor (39).

[0061] The first power is transmitted from the engine (43) to the engine output shaft (44). The engine output shaft drives the driving end of the clutch Y (41) to rotate. At this time, the clutch Y (41) is engaged, and the power is transmitted from the driving end of the clutch Y (41) to the driven end of the clutch Y (41). The driven end of the clutch Y (41) then drives the intermediate first shaft (45) to rotate. The intermediate first shaft B1 gear (46) rotates along with the rotation of the intermediate first shaft (45). The intermediate first shaft B1 gear (46) then drives the intermediate shaft A1 gear (2) to rotate. The intermediate shaft A1 gear (2) drives the intermediate shaft (9) to rotate. The splined hub (4) rotates together with the intermediate shaft (9). At this time, the sliding sleeve E(5) is in the left position. The inner spline of the sliding sleeve E(5) meshes with the spline hub (4) and the outer spline of the intermediate shaft A2 gear (3) at the same time. The power is transmitted from the sliding sleeve E(5) to the spline hub (4) to the intermediate shaft A2 gear (3). The intermediate shaft A2 gear (3) drives the intermediate second shaft B2 gear (40) to rotate. The intermediate second shaft (47) rotates with the rotation of the intermediate second shaft B2 gear (40). The power is then transmitted to the intermediate third shaft (24) through the coupling (29). The sun gear (23) rotates with the intermediate third shaft (24). At this time, the brake Q(11) is engaged, and the gear ring (14) is fixed to the housing (1). Planetary gears (15) rotate and revolve around the sun gear (23) as the sun gear (23) rotates. Planet carrier (26) rotates as the planetary gears (15) revolve, and planet carrier (26) drives the intermediate fourth shaft (22) to rotate. At this time, clutch T (17) is engaged, and power is transmitted from the intermediate fourth shaft (22) to the output shaft through clutch T (17), which ultimately drives the flange (20) to rotate.

[0062] The second power is transmitted from the motor rotor (39) to the second input shaft (37). The second input shaft (37) drives the splined hub (31) to rotate. At this time, the sliding sleeve F (32) is in the left position. The inner spline of the sliding sleeve F (32) meshes with the splined hub (31) and the outer spline of the second input shaft C1 gear (33) at the same time. The power is transmitted from the splined hub (31) to the second input shaft C1 gear (33) through the sliding sleeve F (32). The second input shaft C1 gear (33) drives the auxiliary gearbox high gear (8) to rotate. The rotation of the auxiliary gearbox high gear (8) drives the planetary carrier (26) to rotate. At this time, the second power and the first power are combined. The planetary carrier (26) drives the intermediate fourth shaft (22) to rotate. At this time, the clutch T (17) is engaged. The power is transmitted from the intermediate fourth shaft (22) to the output shaft through the clutch T (17), and finally drives the flange (20) to rotate.

[0063] Reverse 1

[0064] Power is transmitted from the engine (43) to the engine output shaft (44). The engine output shaft drives the driving end of the clutch Y (41) to rotate. At this time, the clutch Y (41) is engaged. Power is transmitted from the driving end of the clutch Y (41) to the driven end of the clutch Y (41). The driven end of the clutch Y (41) then drives the intermediate first shaft (45) to rotate. The intermediate first shaft B1 gear (46) rotates with the rotation of the intermediate first shaft (45). The intermediate first shaft B1 gear (46) then drives the intermediate shaft A1 gear (2) to rotate. The intermediate shaft A1 gear (2) transmits power to the splined hub (4) through the intermediate shaft (9). At this time, the sliding sleeve E(5) is in the left position. The inner spline of the sliding sleeve E(5) meshes with the spline hub (4) and the outer spline of the intermediate shaft A2 gear (3) at the same time, thereby transmitting power to the intermediate second shaft B2 gear (40). The intermediate second shaft (47) rotates under the drive of the intermediate second shaft B2 gear (40), transmitting power to the coupling (29), which in turn drives the intermediate third shaft (24) to rotate. Power is transmitted from the intermediate third shaft (24) to the sun gear (23). The sun gear (23) drives the planet gear (15) to rotate. At this time, the brake W(12) is engaged, and the planet carrier (26) is fixed to the housing (1). Power is transmitted from the planetary gear (15) to the ring gear (14). Since the planetary carrier (26) is fixed, the ring gear (14) rotates in the opposite direction to the sun gear (23). Power is transmitted to the driving end of the clutch R (16) through the ring gear (14). The clutch R (16) is closed. The power of the driving end of the clutch R (16) is transmitted to the output shaft (21) through the clutch housing (18). Finally, the output shaft (21) drives the flange (20) to rotate.

[0065] Reverse 2

[0066] At this time, the power is transmitted to the transmission system by the engine (43) and the motor rotor (39).

[0067] The first power is transmitted from the engine (43) to the engine output shaft (44). The engine output shaft drives the driving end of the clutch Y (41) to rotate. At this time, the clutch Y (41) is engaged, and the power is transmitted from the driving end of the clutch Y (41) to the driven end of the clutch Y (41). The driven end of the clutch Y (41) then drives the intermediate first shaft (45) to rotate. The intermediate first shaft B1 gear (46) rotates with the rotation of the intermediate first shaft (45). The intermediate first shaft B1 gear (46) then drives the intermediate shaft A1 gear (2) to rotate. The intermediate shaft A1 gear (2) transmits the power to the splined hub (4) through the intermediate shaft (9). At this time, the sliding sleeve E(5) is in the left position. The inner spline of the sliding sleeve E(5) meshes with the spline hub (4) and the outer spline of the intermediate shaft A2 gear (3) at the same time, thereby transmitting power to the intermediate second shaft B2 gear (40). The intermediate second shaft (47) rotates under the drive of the intermediate second shaft B2 gear (40), transmitting power to the coupling (29), which in turn drives the intermediate third shaft (24) to rotate. Power is transmitted from the intermediate third shaft (24) to the sun gear (23). The sun gear (23) drives the planet gear (15) to rotate. At this time, the brake W(12) is disengaged, the planet carrier (26) is in a rotatable state, and power is transmitted from the planet gear (15) to the gear ring (14).

[0068] The second power is provided by the reverse rotation of the motor. The power is transmitted from the motor rotor (39) to the second input shaft (37). The second input shaft (37) drives the splined hub (31) to rotate. At this time, the sliding sleeve F (32) is in the left position. The inner spline of the sliding sleeve F (32) meshes with the splined hub (31) and the outer spline of the second input shaft C1 gear (33) at the same time. The power is transmitted from the splined hub (31) to the second input shaft C1 gear (33) through the sliding sleeve F (32). The second input shaft C1 gear (33) drives the auxiliary gearbox high gear (8) to rotate. The rotation of the auxiliary gearbox high gear (8) drives the planet carrier (26) to rotate. The rotation direction of the planet carrier (26) is opposite to the rotation direction of the sun gear (23).

[0069] At this time, the second power and the first power are combined and the power is transmitted to the driving end of the clutch R (16) through the gear ring (14). The clutch R (16) is closed, and the power of the driving end of the clutch R (16) is transmitted to the output shaft (21) through the clutch housing (18). Finally, the output shaft (21) drives the flange (20) to rotate.

[0070] Torque supplement control during gear shifting

[0071] The intermediate shaft A1 gear (2) has z1 teeth, the intermediate shaft A2 gear (3) has z2 teeth, the intermediate shaft A3 gear (6) has z3 teeth, the intermediate first shaft B1 gear (46) has z4 teeth, the intermediate second shaft B2 gear (40) has z5 teeth, the intermediate second shaft B3 gear (36) has z6 teeth, the auxiliary gearbox high gear (8) has z7 teeth, the auxiliary gearbox low gear (27) has z8 teeth, the sun gear (23) has z9 teeth, the gear ring (14) has z10 teeth, the second input shaft C1 gear (33) has z11 teeth, and the second input shaft C2 gear (30) has z12 teeth.

[0072] When performing motor torque control, the actual power system exhibits numerous nonlinearities, including the system's inherent nonlinear stiffness and damping characteristics, as well as external influencing factors such as ambient temperature. Therefore, the system controller requires good robustness. Here, nonlinear sliding mode control is employed, where the target torque that the motor needs to track is x. d (t), where the difference between the target torque being tracked and the current output torque of the motor is e(t);

[0073] e(t) = x d (txt)

[0074] The auxiliary controller is u aux (t):

[0075]

[0076] ρ is the upper bound of the interference, and ε is the up-frequency coefficient (ε > 0).

[0077] The designed controller u(t) is as follows:

[0078]

[0079] u(t) is the output of the control, e(t) is the deviation value input to the controller, and k is the proportional gain coefficient.

[0080] When the transmission shifts gears and the power input from the engine is interrupted, the electric motor increases its output torque and takes over the power output from the engine for a short period of time, thereby reducing or even eliminating vehicle jerking caused by power interruption during gear shifting.

[0081] The torque that the motor needs to compensate for during gear shifts in each gear. The engine's output torque T1 at the flange can be calculated using the following formula:

[0082] T1 = T m ×i m ×η

[0083] T m For engine output torque; i mη is the speed ratio of the engine power transmission route; η is the transmission efficiency.

[0084] The output torque T2 of the motor at the flange can be calculated using the following formula:

[0085] T2 = T c ×i c ×η

[0086] T c i represents the output torque of the motor. c η is the speed ratio of the motor power transmission route; η is the transmission efficiency.

[0087] Total output torque T out It can be calculated using the following formula:

[0088] T out =T1+T2

[0089] When the transmission is in first gear and a gear change is needed, the output motor needs to output torque T. r1 Calculated using the following formula 2.1;

[0090]

[0091] i c1 The transmission ratio of the motor power output route of the transmission when it is in first gear;

[0092] η1 is the transmission efficiency of this power transmission route.

[0093] When a gear shift is required, the vehicle's electronic control unit (HCU), including the motor controller, clutch controller, and engine controller, issues a shift request. The HCU records the output torque T just before the engine power is interrupted. s and the motor's output torque T at this time t Simultaneously, the engine controller sends a torque reduction command to the engine, and the clutch controller controls the clutch Y to gradually disengage from its driving and driven ends. When there is no speed difference between the driving and driven ends of the clutch, the motor controller controls the motor's torque to track the target T. d1 (t) can be calculated using the following formula.

[0094]

[0095] T s1 (t) represents the engine's output torque when shifting gears and reducing torque;

[0096] When a speed difference occurs at the driving and driven ends of the clutch, the motor controller controls the motor to increase torque to track the target torque T. d2 (t) The torque T that the clutch can transmit at this moment, determined by the position of the clutch actuator. f1 (t) is calculated using the formula shown below:

[0097]

[0098] The motor controller gradually increases the motor torque according to the target torque. When the clutch disengages, the transmission performs a gear shift. After the shift is complete, clutch Y engages, at which point T... d3 (t) The torque T that the clutch can transmit at this moment, determined by the position of the clutch actuator. f2 (t) is calculated, as shown in the following formula:

[0099]

[0100] When there is no speed difference between the driving and driven ends of the clutch, T d4 (t) is derived from the engine's torque at this time, and the calculation formula is as follows:

[0101]

[0102] T s2 (t) represents the engine's output torque when it is shifting gears and increasing torque;

[0103] The shift mode is exited only after full engagement, ensuring that the transmission system's output torque remains essentially constant during gear changes, reducing or even eliminating the jerking sensation during shifts. The controller signal transmission process during gear shifts is as follows: Figure 13 As shown.

[0104] Reverse gear torque enhancement control

[0105] When the vehicle enters reverse torque boost mode, the vehicle's electronic control unit (ECU) determines the vehicle's operating condition through vehicle weight, slope, and speed signals, and judges the driver's intention through throttle and brake opening signals. Based on the vehicle's operating condition and the driver's intention, it determines whether to enter drive motor torque boost mode. The specific process is as follows: Figure 14 As shown.

Claims

1. A control method for a hybrid transmission system for a heavy duty vehicle, characterized by, The control method is applied to a hybrid transmission system suitable for heavy trucks, and the control method comprises the following steps: When the hybrid transmission system suitable for heavy trucks is in gear shifting, when a clutch for selectively connecting an engine output shaft and a first intermediate shaft is gradually separated, an automobile electronic control unit calculates a torque reduction value according to a clutch position change, and a motor controls a power input of the motor according to the torque reduction value by using a sliding mode control method, so as to weaken or eliminate an impact caused by power interruption in the gear shifting process; when the hybrid transmission system suitable for heavy trucks is in reverse gear, whether to enter a reverse torque strengthening mode is determined according to a vehicle working condition and a driver intention; when the vehicle enters the reverse torque strengthening mode, the automobile electronic control unit determines the vehicle working condition according to a vehicle weight signal, a vehicle slope signal and a vehicle speed signal, and determines the driver intention according to a throttle opening degree signal and a brake opening degree signal; the required output torque of the motor is calculated according to the vehicle working condition and the driver intention, so as to strengthen an output torque of a transmission output shaft in the reverse gear; The hybrid transmission system suitable for heavy trucks comprises an engine, an engine output shaft, a first intermediate shaft, a second intermediate shaft, a third intermediate shaft, a motor, a second input shaft, a planetary gear set, a fourth intermediate shaft, an output shaft, a clutch housing, a clutch R, a clutch T, a brake W, a clutch E and a brake Q.

2. The control method of the hybrid transmission system for a heavy duty vehicle according to claim 1, characterized by, The intermediate shaft of the transmission system is selectively connected with the intermediate shaft A2 gear and the intermediate shaft A3 gear through the spline hub and the sleeve E; the second input shaft is selectively connected with the second input shaft C1 gear and the second input shaft C2 gear through the spline hub and the sleeve F.

3. The control method of the hybrid transmission system for a heavy duty vehicle according to claim 1, characterized by, The intermediate first shaft and the intermediate second shaft of the transmission system are floatingly connected; the intermediate second shaft and the intermediate third shaft are connected through a shaft coupling; the intermediate shaft is installed in the transmission system shell through a bearing seat; the second input shaft is installed in the transmission system shell through a bearing seat.

Images