A system and method for reusing the output shaft speed of a transmission in an engineering vehicle

Abstract

This invention belongs to the field of vehicle technology, specifically providing a system and method for multiplexing the output shaft speed of an engineering vehicle's transmission. The system includes a vehicle controller, a vehicle instrument cluster, and a transmission controller connected via a CAN bus. The vehicle controller is connected to a transmission input shaft speed sensor via a first relay. The vehicle controller is also connected to a transmission output shaft speed sensor via a second relay. A third relay is connected to both the vehicle instrument cluster and the second relay. The transmission controller is connected to both the first and second relays. The vehicle controller controls the operation of the corresponding relays based on the transmission type configured in the vehicle, connecting the signal paths of the corresponding sensors. After the sensor signal paths are connected, the vehicle controller determines the operating mode and controls the relevant relays accordingly. This provides accurate and reliable speed values, effectively improving the safety of the upper structure's operating mode.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and specifically to a system and method for reusing the output shaft speed of a transmission in an engineering vehicle. Background Technology

[0002] Engineering vehicles are equipped with transfer cases and power take-offs (PTOs) to enable operation in situations such as parking and axle breakage. When superstructure work is carried out on this type of chassis, on the one hand, the output shaft speeds of the PTO and transfer case need to be known; on the other hand, the vehicle speed calculation is different from that of ordinary tractor trucks and cargo trucks, and needs to be combined with the transmission ratio of the transfer case.

[0003] When operating, this type of engineering chassis requires extremely high real-time accuracy and precision in controlling the transmission chain speed. For example, for pumping chassis, it is crucial to prevent insufficient power due to excessively low speed, which could lead to uneven concrete distribution during pumping or even equipment blockage and damage; conversely, it is essential to prevent excessively high speeds when combined with the pumping equipment, which could cause a sudden pressure surge and result in severe impact and equipment failure. Therefore, accurate control of the transmission chain speed signal is absolutely necessary.

[0004] In traditional operating modes, since the gearbox output shaft speed sensor is not connected to the vehicle control unit (VCU), the only way to obtain the drivetrain speed is to add a speed sensor to the power take-off unit (PTO) and then use this sensor to infer the drivetrain speed. This method of obtaining drivetrain speed through inversion reduces the reliability of the drivetrain data. Summary of the Invention

[0005] In traditional operating modes, since the gearbox output shaft speed sensor is not connected to the vehicle control unit (VCU), the only way to obtain the transmission chain speed is to add a speed sensor to the power take-off unit (PTO) and then use this sensor to infer the transmission chain speed. This method of obtaining the transmission chain speed by inversion reduces the reliability of the transmission chain data. This invention provides a system and method for multiplexing the gearbox output shaft speed of engineering vehicles.

[0006] In a first aspect, the technical solution of the present invention provides an engineering vehicle gearbox output shaft speed multiplexing system, including a vehicle controller, a vehicle instrument and a gearbox controller connected via a CAN bus;

[0007] The vehicle controller is connected to the transmission input shaft speed sensor via a first relay; the vehicle controller is connected to the transmission output shaft speed sensor via a second relay; the vehicle controller is also connected to a third relay, which is connected to the vehicle instrument panel and the second relay respectively; the transmission controller is connected to the first relay and the second relay respectively, and the transmission controller is connected to the vehicle controller via the vehicle instrument panel.

[0008] The vehicle controller controls the operation of the corresponding relays to connect the signal paths of the corresponding sensors based on the type of transmission configured in the vehicle.

[0009] After the sensor signal path is connected, the vehicle controller determines the operating mode and controls the relevant relays.

[0010] As a preferred embodiment of the technical solution of the present invention, the vehicle controller is used to determine whether the vehicle is equipped with an AMT transmission or a manual transmission by reading the ETC2 message sent by the transmission controller.

[0011] When the vehicle is equipped with an AMT transmission, the vehicle controller controls the first relay coil to connect the transmission input shaft speed sensor signal to the transmission controller; the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the transmission controller.

[0012] When the vehicle is equipped with a manual transmission, the vehicle controller controls the first relay to connect the transmission input shaft speed sensor signal to the vehicle controller.

[0013] As a preferred embodiment of the technical solution of the present invention, the vehicle controller is used to acquire the gearbox gear position signal, the transfer case position signal, the power take-off position signal, the front axle position signal, and the work switch signal, and to determine whether it is in work mode based on the acquired signals.

[0014] As a preferred embodiment of the technical solution of the present invention, when it is determined that the transmission is a manual transmission and the mode is not in operation, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle instrument, and the vehicle instrument is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed.

[0015] When it is determined that the transmission is manual and in operation mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle controller. The vehicle controller is responsible for collecting the transmission output shaft speed sensor data to verify the speed signal on the transmission chain.

[0016] As a preferred embodiment of the technical solution of the present invention, when the vehicle is equipped with an AMT transmission, the transmission controller calculates the vehicle speed according to the operating mode and sends a vehicle speed signal message.

[0017] When the vehicle is equipped with a manual transmission and is not in working mode, the vehicle instrument calculates the vehicle speed according to the working mode and sends a vehicle speed signal message.

[0018] When the vehicle is equipped with a manual transmission and is in operation mode, the vehicle controller calculates the vehicle speed according to the operation mode and sends a vehicle speed signal message.

[0019] The vehicle's instrument panel reads the vehicle speed signal message to display the vehicle speed.

[0020] As a preferred embodiment of the technical solution of the present invention, the vehicle controller communicates with the vehicle instrument through PWM pulse signals. The PWM pulse signals use different frequencies to represent the devices connected to the current gearbox output shaft sensor, and the PWM pulse signals use a set range of duty cycles to correspond to the vehicle speed values ​​within a set vehicle speed range.

[0021] When the vehicle instrument panel cannot read the vehicle speed signal message, the vehicle speed is identified and displayed by recognizing the PWM pulse signal.

[0022] As a preferred embodiment of the technical solution of this invention, the vehicle speed calculation logic is: V=P*3600*2πR / n / I 总

[0023] In the formula, V represents the vehicle speed, P represents the frequency, R represents the tire rolling radius, and I represents the speed. 总 This indicates the overall speed ratio of the transmission chain, and n represents the number of pulses per revolution of the gearbox output shaft sensor.

[0024] I 总 In non-operational mode: I 总 =i T *i FDX *(i H or i L )*i 后桥 ;

[0025] I 总 In operation mode: I 总 =i T *i FDX *i PTO .

[0026] As a preferred embodiment of the technical solution of the present invention, during parking operations, the vehicle controller reads the engine speed value N. engine , Gearbox input shaft speed N T_IN , gearbox output shaft speed N T_OUT Transfer case countershaft speed N FDX Power take-off output shaft speed N PTO Front axle positioning signal and wheel speed values ​​sent by ABS;

[0027] When the clutch is fully engaged, and the transmission is not in neutral, the transfer case is in neutral, the PTO engagement signal is valid, and the front axle engagement signal is invalid, the following conditions are met:

[0028] N engine =N T_IN =N T_OUT / i T =N FDX / i T =N PTO / (i T *iPTO )

[0029] Among them, the gear ratio i T Transfer case gear ratio i FDX PTO transmission ratio i PTO ;

[0030] If the equations for both sides of the rotation speed are not true, then the position sensor is determined to be faulty.

[0031] After the clutch signal transitions from 1 to 0 for a time interval T4, N is executed. engine The verification, if N T_IN =N T_OUT / i T But N engine ≠N T_IN The system indicates that the clutch is worn and has failed, and outputs a warning message through the vehicle's instrument panel.

[0032] After the clutch signal jumps from 1 to 0 for time T4, and after the power take-off (PTO) position signal jumps from 0 to 1 for time T5, i is executed. PTO The verification, if N T_OUT、 =N FDX But N FDX ≠N PTO / i PTO The system is suspected of having a problem with the power take-off transmission system, and a warning message is output through the vehicle's instrument panel.

[0033] As a preferred embodiment of the technical solution of the present invention, the vehicle controller is provided with a first drive interface, a second drive interface, a third drive interface, an input shaft speed input interface, and an output shaft speed input interface;

[0034] The first drive interface is connected to one end of the first relay coil, the other end of the first relay coil is grounded, the normally open contact of the first relay is connected to the input shaft speed input interface, the normally closed contact of the first relay is connected to the gearbox controller, and the common contact of the first relay is connected to the gearbox input shaft speed sensor.

[0035] The second drive interface is connected to one end of the second relay coil, the other end of the second relay coil is grounded, the normally open contact of the second relay is connected to the common contact of the third relay, the normally closed contact of the second relay is connected to the gearbox controller, and the common contact of the second relay is connected to the gearbox output shaft speed sensor.

[0036] The third drive interface is connected to one end of the third relay coil, the other end of the third relay coil is grounded, the normally open contact of the third relay is connected to the output shaft speed input interface, and the normally closed contact of the third relay is connected to the vehicle instrument panel.

[0037] Secondly, the present invention provides a method for reusing the output shaft speed of a transmission in an engineering vehicle, comprising the following steps:

[0038] The vehicle controller determines whether the vehicle is equipped with an AMT transmission or a manual transmission by reading the ETC2 message sent by the transmission controller.

[0039] When a vehicle is equipped with an AMT transmission, the vehicle controller connects the transmission input shaft speed sensor signal to the transmission controller by controlling the first relay coil, and connects the transmission output shaft speed sensor signal to the transmission controller by controlling the second and third relays.

[0040] When the vehicle is equipped with a manual transmission, the vehicle controller connects the transmission input shaft speed sensor signal to the vehicle controller by controlling the first relay.

[0041] The vehicle controller determines the operating mode and controls the relevant relays accordingly.

[0042] As a preferred embodiment of the technical solution of the present invention, the steps of the vehicle controller determining the operating mode and controlling the relevant relays include:

[0043] The vehicle controller acquires the gearbox gear position signal, transfer case position signal, power take-off position signal, front axle position signal, and work switch signal, and determines whether it is in work mode based on the acquired signals.

[0044] When the transmission is in manual mode and not in operating mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle instrument panel, which is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed.

[0045] When the transmission is in manual mode and the operating mode is active, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle controller. The vehicle controller is responsible for collecting the transmission output shaft speed sensor data to verify the speed signal on the drivetrain.

[0046] As can be seen from the above technical solutions, the present invention has the following advantages:

[0047] By identifying vehicle configuration and operating mode, the core of the drivetrain—the gearbox output shaft speed signal—is distributed to different controllers for acquisition based on the vehicle configuration and operating mode, achieving multiplexing across multiple operating conditions. This allows for effective verification of the speed signal's rationality and provides accurate and reliable speed values, significantly improving the safety of the superstructure's operating modes. Multiplexing the speed signal eliminates the need for a power take-off (PTO) position speed sensor, reducing costs; furthermore, it allows for data verification using two sensors, increasing system redundancy and improving the reliability of drivetrain data.

[0048] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects.

[0049] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic block diagram of a system according to an embodiment of the present invention.

[0052] Figure 2 This is a schematic block diagram of a system according to another embodiment of the present invention.

[0053] Figure 3 This is a flowchart illustrating the process of determining the configuration position of the gearbox output shaft sensor according to an embodiment of the present invention.

[0054] Figure 4 This is a schematic flowchart of a method according to an embodiment of the present invention. Detailed Implementation

[0055] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0056] like Figure 1 As shown, this embodiment of the invention provides a transmission output shaft speed multiplexing system for engineering vehicles, including a vehicle controller, a vehicle instrument panel, and a transmission controller connected via a CAN bus;

[0057] The vehicle controller is connected to the transmission input shaft speed sensor via a first relay; the vehicle controller is connected to the transmission output shaft speed sensor via a second relay; the vehicle controller is also connected to a third relay, which is connected to the vehicle instrument panel and the second relay respectively; the transmission controller is connected to the first relay and the second relay respectively, and the transmission controller is connected to the vehicle controller via the vehicle instrument panel.

[0058] The vehicle controller controls the operation of the corresponding relays to connect the signal paths of the corresponding sensors based on the type of transmission configured in the vehicle.

[0059] After the sensor signal path is connected, the vehicle controller determines the operating mode and controls the relevant relays.

[0060] It should be noted that the vehicle controller is used to determine whether the vehicle is equipped with an AMT transmission or a manual transmission by reading the ETC2 message sent by the transmission controller.

[0061] When the vehicle is equipped with an AMT transmission, the vehicle controller controls the first relay coil to connect the transmission input shaft speed sensor signal to the transmission controller; the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the transmission controller.

[0062] When the vehicle is equipped with a manual transmission, the vehicle controller controls the first relay to connect the transmission input shaft speed sensor signal to the vehicle controller.

[0063] In some embodiments, the vehicle controller is used to acquire the gearbox gear position signal, transfer case position signal, power take-off position signal, front axle position signal, and work switch signal, and determine whether it is a work mode based on the acquired signals.

[0064] Specifically, in this embodiment of the invention, the first relay is relay C, the second relay is relay A, and the third relay is relay B;

[0065] This system mainly includes the vehicle control unit (VCU), vehicle instrument cluster, engine ECU, and transmission control unit (TCU). The acquired switching signals include: clutch signal, transfer case high gear engagement signal, transfer case low gear engagement signal, power take-off (PTO) engagement signal, and front axle engagement signal; the acquired speed signals include: transmission input shaft speed value N. T_IN , gearbox output shaft speed N T_OUT Transfer case countershaft speed N FDX Power take-off output shaft speed N PTO The collected message information includes: engine speed value; the drive output pins are: relays A / B / C, where the switches controlled by relays A / B / C are double-throw switches.

[0066] This implementation plan enables power take-off in the event of a broken axle during parking operations, and is equipped with a transfer case and a power take-off unit.

[0067] The transfer case has three gears: high, low, and neutral. The corresponding gear ratios are i... H i LThe VCU determines the transfer case gear by checking the gear position signal and sends the specific gear to the vehicle's CAN bus via a TCI message. 0x00 indicates transfer case neutral, 0x01 indicates transfer case low gear, and 0x10 indicates transfer case high gear. This information is used by other controllers for vehicle speed calculation. The operating mode requires the transfer case to be in neutral. The gear position determination logic is shown in Table 1.

[0068] Table 1

[0069]

[0070]

[0071] Job mode determination logic:

[0072] 1. The transmission is not in neutral, and the transfer case is in neutral;

[0073] 2. Engage the handbrake;

[0074] 3. Depress the clutch;

[0075] 4. Front axle position switch is ineffective;

[0076] 5. The rising edge of the operating switch is valid;

[0077] If the rising edge of the work switch is valid after conditions 1 / 2 / 3 / 4 are met, it is considered that the upper equipment work mode has been entered. Before conditions 1 / 2 / 3 / 4 are met, the rising edge of the work switch is invalid.

[0078] In some embodiments, when it is determined that the transmission is a manual transmission and not in working mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle instrument panel, which is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed.

[0079] When it is determined that the transmission is manual and in operation mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle controller. The vehicle controller is responsible for collecting the transmission output shaft speed sensor data to verify the speed signal on the transmission chain.

[0080] When a vehicle is equipped with an AMT transmission, the transmission controller calculates the vehicle speed according to the operating mode and sends a vehicle speed signal message.

[0081] When the vehicle is equipped with a manual transmission and is not in working mode, the vehicle instrument calculates the vehicle speed according to the working mode and sends a vehicle speed signal message.

[0082] When the vehicle is equipped with a manual transmission and is in operation mode, the vehicle controller calculates the vehicle speed according to the operation mode and sends a vehicle speed signal message.

[0083] The vehicle's instrument panel reads the vehicle speed signal message to display the vehicle speed.

[0084] like Figure 2 As shown, the vehicle controller is equipped with a first drive interface, a second drive interface, a third drive interface, an input shaft speed input interface, and an output shaft speed input interface. The first drive interface is connected to one end of the coil of relay C, and the other end of the coil of relay C is grounded. The normally open contact of relay C is connected to the input shaft speed input interface, the normally closed contact of relay C is connected to the transmission controller, and the common contact of relay C is connected to the transmission input shaft speed sensor. The second drive interface is connected to one end of the coil of relay A, and the other end of the coil of relay A is grounded. The normally open contact of relay A is connected to the common contact of relay B, the normally closed contact of relay A is connected to the transmission controller, and the common contact of relay A is connected to the transmission output shaft speed sensor. The third drive interface is connected to one end of the coil of relay B, and the other end of the coil of relay B is grounded. The normally open contact of relay B is connected to the output shaft speed input interface, and the normally closed contact of relay B is connected to the vehicle instrument panel. In this embodiment of the invention, the first drive interface is the relay C drive port, the second drive interface is the relay A drive port, and the third drive interface is the relay B drive port. Based on the above relay connection method, the specific implementation of the transmission input shaft and output shaft speed sensor configuration functions is as follows: Figure 3 As shown;

[0085] After the vehicle is initially powered on, the vehicle instrument panel, TCU, and VCU are initialized respectively.

[0086] The TCU sends out the ETC2 message within the power-on T1 time (default 100ms, configurable);

[0087] Within the power-on time T2 (default 300ms, configurable), the VCU completes the reading of the ETC2 message and the initialization of the drive pins of relays A, B, and C. Within the power-on time T2 (default 300ms, configurable), the VCU reads the ETC2 message. If the message is found, the vehicle is considered to have an AMT transmission; otherwise, it is considered to have a manual transmission.

[0088] When the vehicle is equipped with an AMT transmission, the VCU controls the C coil of the relay to be de-energized, and the transmission input shaft speed sensor signal is connected to the TCU; the VCU controls the A / B coil of the relay to be de-energized, and the transmission output shaft speed sensor signal is connected to the TCU; the VCU sends a VCU1 message to the vehicle CAN bus.

[0089] Within the power-on time T3 (default 500ms, configurable), the VCU determines the operating mode and drives the relevant relays.

[0090] When the vehicle is equipped with a manual transmission, the VCU controls the relay C coil to be energized, and the transmission input shaft speed sensor signal is connected to the VCU.

[0091] When the transmission is determined to be a manual transmission and not in operating mode, the VCU controls the B coil of the relay to be de-energized and the A coil of the relay to be energized. The transmission output shaft speed sensor signal is connected to the instrument panel, which is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed. The VCU sends a VCU1 message to the vehicle's CAN bus.

[0092] When the transmission is determined to be a manual transmission and in operating mode, the VCU controls relay A coil to be energized and relay B coil to be energized. The VCU is responsible for acquiring the transmission output shaft speed sensor data and verifying the speed signal on the drivetrain. The VCU sends a VCU 1 message to the vehicle's CAN bus.

[0093] The time parameters T1 / T2 / T3 are configurable, but T1 must be satisfied. <T2<T3。

[0094] In some embodiments, the specific process of vehicle speed display and message transmission includes:

[0095] After the vehicle is powered on, when the vehicle is equipped with an AMT transmission, the TCU will start sending the vehicle speed signal TCO1 message normally at the time of "T2+10 task cycle".

[0096] When the system is determined to be a manual transmission and not in working mode, the instrument panel will begin sending the vehicle speed signal TCO1 message normally at the time of "T3+10 task cycle".

[0097] When the transmission is identified as a manual transmission and in operation mode, the VCU starts sending the vehicle speed signal TCO1 message normally at the "T3+10 task cycle" time. In this mode, the VCU collects the speed sensor of the gearbox output shaft, but does not fill the vehicle speed message. The message is continuously sent and the vehicle speed is 0.

[0098] Ten task cycles are used for processing including vehicle speed calculation; the instrument reads the vehicle speed value from TCO1 and displays the vehicle speed.

[0099] The vehicle speed calculation logic is as follows:

[0100] V = P * 3600 * 2πR / n / I 总

[0101] In the formula, V represents the vehicle speed, P represents the frequency, R represents the tire rolling radius, and I represents the speed. 总 This indicates the overall speed ratio of the transmission chain, and n indicates the number of pulses per revolution of the gearbox output shaft sensor.

[0102] I 总In non-operational mode: I 总 =i T *i FDX *(i H or i L )*i 后桥 ;

[0103] I 总 In operation mode: I 总 =i T *i FDX *i PTO ;

[0104] In non-operation mode, vehicle speed verification can be performed by cross-checking the calculated TCO1 value, the wheel speed value provided by ABS, and the vehicle speed value calculated by the built-in recorder. VCU and ABS verification: In non-operation mode, the VCU reads the bus TCO1 vehicle speed value and the EBC1 wheel speed value sent by ABS for verification. If the absolute value of the difference between the two is within 3km / h, it is considered reasonable. If it exceeds this value, the vehicle speed calculation is considered incorrect.

[0105] In some embodiments, the vehicle controller communicates with the vehicle instrument panel via PWM pulse signals. The PWM pulse signals use different frequencies to represent the devices connected to the current transmission output shaft sensor, and the PWM pulse signals use a set range of duty cycles to correspond to the vehicle speed values ​​within a set speed range. When the vehicle instrument panel cannot read the vehicle speed signal message, the vehicle speed is identified and displayed by recognizing the PWM pulse signals.

[0106] To prevent problems with the vehicle's CAN bus, hard-wired verification has been added between the VCU and the instrument cluster, as well as between the TCU and the instrument cluster, using PWM pulse signals.

[0107] The PWM pulse signals between the VCU and the instrument cluster use different frequencies to represent the current transmission output shaft sensor connected to the device.

[0108] When the frequency is 200Hz, it indicates that the gearbox output shaft sensor is connected to the AMT controller.

[0109] When the frequency is 400Hz, it indicates that the gearbox output shaft sensor is connected to the instrument.

[0110] When the frequency is 600Hz, it indicates that the gearbox output shaft sensor is connected to the VCU controller.

[0111] When the frequency between the VCU and the instrument cluster is 600 Hz, a duty cycle of 5% to 100% is used to correspond to vehicle speed values ​​of 5 km / h to 100 km / h.

[0112] When the vehicle speed is less than 5 km / h, the continuous output duty cycle is 5%;

[0113] When the frequency between the VCU and the instrument is 400Hz, the TCU and the instrument use a duty cycle of 5% to 100% to correspond to the vehicle speed values ​​of 5km / h-100km / h. When the vehicle speed is less than 5km / h, the duty cycle is continuously 5%.

[0114] When the instrument panel cannot read the vehicle speed message, the vehicle speed is identified and displayed by recognizing the PWM pulse. This prevents abnormal vehicle speed display when the instrument panel cannot connect to the CAN line, which could affect the driver's judgment and cause driving danger.

[0115] It should be noted that when the operator presses the work mode switch, the VCU judges the handbrake signal, vehicle speed signal, and neutral signal, determines the order, and determines the entry of the work mode control switching pin. It then controls the relay to close, and connects the pulse signal to the VCU. The VCU calculates the output shaft speed and sends the upper body work mode to the vehicle network. When the instrument receives this signal, it stops displaying the vehicle speed and calculating the mileage, and controls the vehicle speed pointer to return to zero.

[0116] During parking operations, the vehicle controller reads the engine speed value N. engine , Gearbox input shaft speed N T_IN , gearbox output shaft speed N T_OUT Transfer case countershaft speed N FDX Power take-off output shaft speed N PTO Front axle positioning signal and wheel speed values ​​sent by ABS;

[0117] Taking the 4x2 model as an example, when the clutch is fully engaged, and the transmission is not in neutral, the transfer case is in neutral, the PTO engagement signal is valid, and the front axle engagement signal is invalid, the following conditions must be met:

[0118] N engine =N T_IN =N T_OUT / i T =N FDX / i T =N PTO / (i T *i PTO )

[0119] Among them, the gear ratio i T Transfer case gear ratio i FDX PTO transmission ratio i PTO ;

[0120] According to the drivetrain position, the aforementioned speed signals are installed sequentially from front to back at their respective positions on the drivetrain. Based on the failure probability distribution, the scenario of two adjacent sensors failing simultaneously is ignored. The signal verification strategy is as follows: in the equation, if neither the equation for the speed on the left nor the right side is true, it is considered that the sensor at that position is faulty. For example: N engine ≠N T_IN And N T_IN ≠N T_OUT / i T Then N is considered T_IN The signal is incorrect.

[0121] After the clutch signal transitions from 1 to 0 for a period of time T4 (calibrable, default 2.5 seconds), N is executed. engine The verification, if N T_IN =N T_OUT / i T But N engine ≠N T_IN The system indicates that the clutch is worn and has failed, and outputs a warning message through the vehicle's instrument panel.

[0122] After the clutch signal transitions from 1 to 0 for time T4 (calibrable, default 2.5 seconds), and after the power take-off (PTO) position signal transitions from 0 to 1 for time T5 (calibrable, default 1 second), i... PTO The verification, if N T_OUT、 =N FDX But N FDX ≠N PTO / i PTO The system is suspected of having a problem with the power take-off transmission system, and a warning message is output through the vehicle's instrument panel.

[0123] like Figure 4 As shown in the figure, an embodiment of the present invention provides a method for reusing the output shaft speed of a transmission in an engineering vehicle, comprising the following steps:

[0124] Step 1: The vehicle controller determines whether the vehicle is equipped with an AMT transmission or a manual transmission by reading the ETC2 message sent by the transmission controller;

[0125] Step 2: When the vehicle is equipped with an AMT transmission, the vehicle controller connects the transmission input shaft speed sensor signal to the transmission controller by controlling the first relay coil, and connects the transmission output shaft speed sensor signal to the transmission controller by controlling the second and third relays; proceed to step 4.

[0126] Step 3: When the vehicle is equipped with a manual transmission, the vehicle controller connects the transmission input shaft speed sensor signal to the vehicle controller by controlling the first relay; proceed to step 4.

[0127] Step 4: The vehicle controller determines the operating mode and controls the relevant relays accordingly.

[0128] In some embodiments, the steps of the vehicle controller determining the operating mode and controlling the relevant relays include:

[0129] Step 41: The vehicle controller acquires the transmission gear position signal, transfer case position signal, power take-off position signal, front axle position signal, and work switch signal, and determines whether it is in work mode based on the acquired signals;

[0130] Step 42: When the transmission is manual and not in working mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle instrument panel, which is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed.

[0131] Step 43: When the transmission is manual and in operation mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle controller. The vehicle controller is responsible for collecting the transmission output shaft speed sensor signal to verify the speed signal on the transmission chain.

[0132] In some embodiments, the vehicle controller is provided with a first drive interface, a second drive interface, a third drive interface, an input shaft speed input interface, and an output shaft speed input interface. The first drive interface is connected to one end of a first relay coil, the other end of the first relay coil is grounded, the normally open contact of the first relay is connected to the input shaft speed input interface, the normally closed contact of the first relay is connected to the transmission controller, and the common contact of the first relay is connected to the transmission input shaft speed sensor. The second drive interface is connected to one end of a second relay coil, the other end of the second relay coil is grounded, the normally open contact of the second relay is connected to the common contact of the third relay, the normally closed contact of the second relay is connected to the transmission controller, and the common contact of the second relay is connected to the transmission output shaft speed sensor. The third drive interface is connected to one end of a third relay coil, the other end of the third relay coil is grounded, the normally open contact of the third relay is connected to the output shaft speed input interface, and the normally closed contact of the third relay is connected to the vehicle instrument panel. Based on the above relay connection method, the specific implementation of the transmission input shaft and output shaft speed sensor configuration functions includes the following:

[0133] After the vehicle is initially powered on, the vehicle instrument panel, TCU, and VCU are initialized respectively.

[0134] The TCU sends out the ETC2 message within the power-on T1 time (default 100ms, configurable);

[0135] Within the power-on time T2 (default 300ms, configurable), the VCU completes the reading of the ETC2 message and the initialization of the drive pins of relays A, B, and C. Within the power-on time T2 (default 300ms, configurable), the VCU reads the ETC2 message. If the message is found, the vehicle is considered to have an AMT transmission; otherwise, it is considered to have a manual transmission.

[0136] When the vehicle is equipped with an AMT transmission, the VCU controls the C coil of the relay to be de-energized, and the transmission input shaft speed sensor signal is connected to the TCU; the VCU controls the A / B coil of the relay to be de-energized, and the transmission output shaft speed sensor signal is connected to the TCU; the VCU sends a VCU 1 message to the vehicle CAN bus.

[0137] Within the power-on time T3 (default 500ms, configurable), the VCU determines the operating mode and drives the relevant relays.

[0138] When the vehicle is equipped with a manual transmission, the VCU controls the relay C coil to be energized, and the transmission input shaft speed sensor signal is connected to the VCU.

[0139] When the system is determined to be a manual transmission and not in operating mode, the VCU controls the B coil of the transmission to be de-energized and the A coil of the transmission to be energized. The transmission output shaft speed sensor signal is connected to the instrument panel, which is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed. The VCU sends a VCU 1 message to the vehicle's CAN bus.

[0140] When the system is determined to be a manual transmission and in operating mode, the VCU energizes both relay A and relay B coils. The VCU is responsible for acquiring the transmission output shaft speed sensor data and verifying the speed signals on the drivetrain. The VCU sends a VCU 1 message to the vehicle's CAN bus.

[0141] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A speed reuse system for the output shaft of a transmission in an engineering vehicle, characterized in that, This includes the vehicle controller, vehicle instrument cluster, and transmission controller, all connected via a CAN bus. The vehicle controller is connected to a transmission input shaft speed sensor via a first relay; the vehicle controller is connected to a transmission output shaft speed sensor via a second relay; the vehicle controller is also connected to a third relay, which is connected to both the vehicle instrument panel and the second relay; the transmission controller is connected to both the first relay and the second relay. The vehicle controller controls the operation of the corresponding relays to connect the signal paths of the corresponding sensors based on the type of transmission configured in the vehicle. After the sensor signal path is connected, the vehicle controller determines the operating mode and controls the relevant relays accordingly. When it is determined that the transmission is manual and not in working mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle instrument panel, which is then responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed. When it is determined that the transmission is manual and the operating mode is active, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle controller. The vehicle controller is responsible for collecting the transmission output shaft speed sensor data to verify the speed signal on the transmission chain. The vehicle controller is used to determine whether the vehicle is equipped with an AMT transmission or a manual transmission by reading the ETC2 message sent by the transmission controller. When the vehicle is equipped with an AMT transmission, the vehicle controller controls the first relay coil to connect the transmission input shaft speed sensor signal to the transmission controller; the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the transmission controller. When the vehicle is equipped with a manual transmission, the vehicle controller controls the first relay to connect the transmission input shaft speed sensor signal to the vehicle controller. The vehicle controller is used to acquire transmission gear position signals, transfer case gear signals, power take-off position signals, front axle position signals, and work switch signals, and to determine whether it is in work mode based on the acquired signals.

2. The engineering vehicle gearbox output shaft speed reuse system according to claim 1, characterized in that, When a vehicle is equipped with an AMT transmission, the transmission controller calculates the vehicle speed according to the operating mode and sends a vehicle speed signal message. When the vehicle is equipped with a manual transmission and is not in working mode, the vehicle instrument calculates the vehicle speed according to the working mode and sends a vehicle speed signal message. When the vehicle is equipped with a manual transmission and is in operation mode, the vehicle controller calculates the vehicle speed according to the operation mode and sends a vehicle speed signal message. The vehicle's instrument panel reads the vehicle speed signal message to display the vehicle speed.

3. The transmission output shaft speed reuse system for engineering vehicles according to claim 2, characterized in that, The vehicle controller communicates with the vehicle instrument panel through PWM pulse signals. The PWM pulse signals use different frequencies to represent the devices connected to the current transmission output shaft sensor. The PWM pulse signals use a set range of duty cycles to correspond to the vehicle speed values ​​within a set speed range. When the vehicle instrument panel cannot read the vehicle speed signal message, the vehicle speed is identified and displayed by recognizing the PWM pulse signal.

4. The transmission output shaft speed reuse system for engineering vehicles according to claim 2, characterized in that, The vehicle speed calculation logic is: V = P × 3600 × 2πR / n / I 总 In the formula, V represents the vehicle speed, P represents the frequency, R represents the tire rolling radius, and I represents the speed. 总 This indicates the overall speed ratio of the transmission chain, and n indicates the number of pulses per revolution of the gearbox output shaft sensor.

5. The transmission output shaft speed reuse system for engineering vehicles according to claim 1, characterized in that, The vehicle controller is equipped with a first drive interface, a second drive interface, a third drive interface, an input shaft speed input interface, and an output shaft speed input interface; The first drive interface is connected to one end of the first relay coil, the other end of the first relay coil is grounded, the normally open contact of the first relay is connected to the input shaft speed input interface, the normally closed contact of the first relay is connected to the gearbox controller, and the common contact of the first relay is connected to the gearbox input shaft speed sensor. The second drive interface is connected to one end of the second relay coil, the other end of the second relay coil is grounded, the normally open contact of the second relay is connected to the common contact of the third relay, the normally closed contact of the second relay is connected to the gearbox controller, and the common contact of the second relay is connected to the gearbox output shaft speed sensor. The third drive interface is connected to one end of the third relay coil, the other end of the third relay coil is grounded, the normally open contact of the third relay is connected to the output shaft speed input interface, and the normally closed contact of the third relay is connected to the vehicle instrument panel.

6. A method for reusing the output shaft speed of a transmission in an engineering vehicle, applicable to the transmission output shaft speed reusing system of any one of claims 1-5, characterized in that, Includes the following steps: The vehicle controller determines whether the vehicle is equipped with an AMT transmission or a manual transmission by reading the ETC2 message sent by the transmission controller. When a vehicle is equipped with an AMT transmission, the vehicle controller connects the transmission input shaft speed sensor signal to the transmission controller by controlling the first relay coil, and connects the transmission output shaft speed sensor signal to the transmission controller by controlling the second and third relays. When the vehicle is equipped with a manual transmission, the vehicle controller connects the transmission input shaft speed sensor signal to the vehicle controller by controlling the first relay. The vehicle controller determines the operating mode and controls the relevant relays accordingly. The steps by which the vehicle controller determines the operating mode and controls the relevant relays include: The vehicle controller acquires the gearbox gear position signal, transfer case gear position signal, power take-off position signal, front axle position signal, and work switch signal, and determines whether it is in work mode based on the acquired signals; When the transmission is in manual mode and not in operating mode, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle instrument panel, which is responsible for collecting the transmission output shaft speed sensor data for displaying the vehicle speed. When the transmission is in manual mode and the operating mode is active, the vehicle controller controls the second and third relays to connect the transmission output shaft speed sensor signal to the vehicle controller. The vehicle controller is responsible for collecting the transmission output shaft speed sensor data to verify the speed signal on the drivetrain.

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