Gear shifting safety redundancy protection system and method for tractor

Abstract

A tractor gear shifting safety redundancy protection system comprises a controller, an FNR reversing handle and an engine ECU, the FNR reversing handle outputs an N-gear signal to a bus, the engine ECU transmits rotating speed information to the bus, the controller receives and stores the rotating speed information of the engine at the previous moment, after the N-gear signal is obtained, whether the current rotating speed changes compared with the previous moment or not is compared, and if yes, the engine ECU transmits the rotating speed information to the bus. And judging whether the N-gear signal is invalid or not, and giving an instruction. And if the rotating speed information does not change, the controller performs data interaction with the engine ECU according to a preset CAN communication protocol, and sends a flameout instruction.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle safety control, and in particular to a tractor gear shift safety redundancy protection system and method. Background Art

[0002] When the tractor is driving, the power of the engine is transmitted to the wheels through the transmission system such as the gearbox. The engine needs to output enough power to overcome the resistance of the vehicle (including air resistance, rolling resistance, etc.). When switching to N gear, the power transmission is cut off, the engine load suddenly decreases, and the engine speed will increase. Subsequently, the engine ECU senses the load change and reduces the fuel injection amount, causing the engine speed to drop to idle state. However, in some abnormal conditions, such as the hydraulic valve group is stuck, the signal transmission is interrupted and the clutch is not cut off, etc., the engine speed may remain at the current speed and does not change after the N gear signal is input, resulting in the vehicle being unable to stop normally, threatening driving safety. Summary of the invention

[0003] Based on this, the present invention provides a tractor gear shift safety redundant protection system and method. When the vehicle inputs the N gear signal, the failure of the N gear signal is promptly identified by monitoring and comparing the engine speed, and a shutdown command is taken to shut down the engine to ensure that the vehicle can be parked safely and avoid potential safety accidents.

[0004] Specifically, the tractor gear shift safety redundant protection system includes a controller, an FNR reversing handle, and an engine ECU. The FNR reversing handle outputs an N gear signal to a bus, and the engine ECU transmits the speed information to the bus. The controller receives and stores the engine speed information at the previous moment. After obtaining the N gear signal, the controller compares whether the current speed has changed compared with the previous moment, determines whether the N gear signal is invalid, and issues an instruction.

[0005] Furthermore, if the speed information does not change, the controller exchanges data with the engine ECU according to a preset CAN communication protocol and sends a shutdown command.

[0006] Second, the tractor gear shift safety redundant protection method includes: S1: The controller obtains and stores the engine speed information V0 at the previous moment through the bus; S2: Receive the N gear signal and obtain the current engine speed V1; S3: Compare the speeds V1 and V0 to determine whether V1 is equal to V0; Yes, that is, the engine speed has not changed, and it is judged that the current N gear signal is invalid, and there is a risk that the vehicle cannot be stopped; S4: The controller starts the redundant protection program, communicates with the engine ECU, and sends it a shutdown command to shut down the engine to ensure parking safety.

[0007] In the above step S3, if V1>V0, and then it is reduced to idle speed, that is, the engine speed changes, it is judged that the current vehicle can be parked normally. At this time, the controller has responded after obtaining the N gear signal, and the responding electronic control circuit and hydraulic circuit are working normally. The controller has instructed the electromagnetic reversing valve to act, and the electromagnetic reversing valve is closed, so that the hydraulic clutch is separated from the power source.

[0008] The present invention has at least the following beneficial effects: Significantly improve safety: The switching safety redundant protection method of the present invention effectively solves the safety problem that the vehicle cannot stop normally due to the failure of the N gear signal. Under abnormal conditions such as the hydraulic valve group being stuck and the signal transmission being interrupted, the hydraulic clutch is not cut off and is not separated from the power source. Through accurate monitoring and comparison of the engine speed, the fault can be judged and responded in time to avoid the vehicle being out of control, greatly reducing the risk of safety accidents such as collisions.

[0009] Simple and efficient: The entire protection method is based on the existing vehicle bus system and engine ECU communication architecture, without the need for vehicle hardware modification and complex system reconstruction. Efficient redundant protection function can be achieved simply by collecting, analyzing and processing the engine speed signal through the controller, and transmitting simple communication instructions with the engine ECU. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 , is a communication principle block diagram of the redundant protection method of the present invention; Figure 2 , is a flow chart of the control method of the present invention; 1-controller, 2-FNR gear signal, 3-reversing valve, 4-engine ECU. DETAILED DESCRIPTION

[0011] The following will be combined with the accompanying drawings to clearly and completely describe the implementation methods of the present invention. Obviously, the described embodiments are only some embodiments of the present invention. Based on the described embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The terms "connected" and "connected" in the present invention should be understood in a broad sense.

[0012] Combination Figure 1The tractor gear shift safety redundant protection system includes a controller, an FNR reversing handle, and an engine ECU. The FNR reversing handle outputs the N gear signal to the bus, and the engine ECU transmits the speed information to the bus. During the normal operation of the vehicle, the vehicle's electronic control system, i.e., the controller 1, continuously monitors the gear signal and the engine operating parameters, including the engine speed information, through the bus. When the driver switches the FNR gear signal 2 to the N gear, the gear signal is output to the bus. On the one hand, the controller 1 quickly obtains this signal change and outputs an electrical signal to the solenoid valve group. In the present invention, the reversing valve 3 is used as an example for explanation. The reversing valve 3 is closed, the hydraulic oil is cut off from being delivered to the wet clutch, and the clutch is separated from the engine flywheel.

[0013] On the other hand, when switching to N gear, the power transmission is cut off, the engine load suddenly decreases, the engine speed will increase, and then the engine ECU senses the load change and reduces the fuel injection amount, causing the engine speed to drop to idle.

[0014] If the hydraulic system valve group is stuck, signal transmission is interrupted, or other abnormal conditions occur, the hydraulic clutch will not be disconnected from the power source, which may cause a collision or other safety accidents. At this time, the controller accurately monitors the engine speed and obtains speed information from the bus. After receiving the N gear signal, it compares the current speed with the previous speed information to determine whether the speed has changed, thereby determining whether there is a parking trend and responding. It can detect faults in time and start redundant protection to prevent the vehicle from being out of control and reduce the risk of accidents.

[0015] Combination Figure 2 , the tractor gear shift safety redundant protection method includes: S1: The controller obtains and stores the engine speed information V0 at the previous moment through the bus; S2: Receive the N gear signal and obtain the current engine speed V1; S3: Compare the speeds V1 and V0 to determine whether V1 is equal to V0; Yes, that is, the engine speed has not changed, and it is judged that the current N gear signal is invalid, and there is a risk that the vehicle cannot be stopped; S4: The controller starts the redundant protection program, communicates with the engine ECU, and sends it a shutdown command to shut down the engine to ensure parking safety.

[0016] The engine speed sensor transmits the current speed to the engine ECU, which is then processed by the ECU and transmitted to the bus. The controller obtains the current speed V1 through the bus and compares it with the speed V0 stored at the previous moment. If the two are equal, it means that the engine speed has not decreased due to the gear shift to N gear. At this time, the controller determines that the N gear signal is invalid and immediately activates the redundant protection mechanism.

[0017] The controller exchanges data with the engine ECU according to the preset CAN communication protocol and sends a shutdown command. After receiving the command, the engine ECU gradually cuts off the fuel injection and ignition systems according to the shutdown program set inside it, stops the engine, and finally achieves safe parking of the vehicle, effectively avoiding the dangerous situation of the vehicle being unable to stop due to the failure of the N gear.

[0018] In the above step S3, if V1>V0, then the engine speed is reduced to idle speed, that is, the engine speed first increases and then decreases after receiving the N gear signal, and it is judged that the current vehicle can be parked normally. At this time, the controller has responded after obtaining the N gear signal, and the electronic control circuit and hydraulic circuit that separate the clutch from the power source are working normally, that is, the controller has instructed the electromagnetic reversing valve to act, the electromagnetic reversing valve is closed, and the hydraulic clutch is separated from the power source.

[0019] In the present invention, the entire protection method is based on the existing vehicle bus system and engine ECU communication architecture, and there is no need to modify the vehicle hardware and reconstruct the system. Efficient redundant protection function can be achieved by simply collecting, comparing and judging the engine speed signal through the controller and transmitting simple communication instructions with the engine ECU.

[0020] The above-mentioned vehicle parking safety redundant protection method and device can significantly improve the safety and reliability of the vehicle parking process, reduce the safety risks caused by system failures, and provide strong protection for the life and property safety of drivers and passengers.

Claims

1. The tractor gear shift safety redundant protection system is characterized by: Including controller, FNR reversing handle, engine ECU, The FNR reversing handle outputs the N gear signal to the bus; The engine ECU transmits the speed information to the bus; The controller receives and stores the engine speed information of the previous moment. After obtaining the N gear signal, it compares whether the current speed has changed compared with the previous moment, determines whether the N gear signal is invalid, and issues an instruction.

2. The tractor gear shift safety redundant protection system according to claim 1, characterized in that: When the speed information does not change, the controller exchanges data with the engine ECU according to a preset CAN communication protocol and sends a shutdown instruction.

3. A tractor gear shift safety redundant protection method, comprising: S1: The controller obtains and stores the engine speed information V0 at the previous moment through the bus; S2: Receive the N gear signal and obtain the current engine speed V1; S3: Compare the speeds V1 and V0 to determine whether V1 is equal to V0; Yes, that is, the engine speed has not changed, and it is judged that the current N gear signal is invalid, and there is a risk that the vehicle cannot be stopped; S4: The controller starts the redundant protection program, communicates with the engine ECU, and sends it a shutdown command to shut down the engine to ensure parking safety.

4. The vehicle safety redundancy protection method according to claim 3, characterized in that: In the above step S3, if V1>V0, then the speed is reduced to idle speed, and it is determined that the current vehicle can be parked normally.

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