A control system and control method for an AMT gearbox of a fire truck

Abstract

The present invention discloses a control system and a control method for an AMT gearbox of a fire truck, and mainly relates to the technical field of gearbox control. The main structure includes an AMT gear shift controller, an engine ECU and a BBM body controller, wherein the AMT gearbox controller and the engine ECU are connected by a CAN bus bidirectional data connection, and the engine ECU and the BBM body controller are connected by a CAN bus bidirectional data connection. The beneficial effect of the present invention is that it can realize the gear shifting and automatic clutching of the AMT gearbox under different working conditions, accurately control the gear shifting timing and clutch state control, and enhance the gear shifting smoothness and driving experience.

Description

Technical Field

[0001] The present invention relates to the technical field of gearbox control, and in particular to a control system and a control method for an AMT gearbox of a fire truck. Background Art

[0002] At present, domestic fire trucks are mainly equipped with manual transmissions, which have high requirements on the driver's operation when performing firefighting and emergency rescue tasks.

[0003] Foreign brands such as Scania and Mercedes-Benz have gradually applied AMT / AT gearboxes to fire emergency vehicles, greatly improving the driver's operating flexibility and improving the vehicle's attendance efficiency and work efficiency.

[0004] With the application and development of AMT / AT transmission technology in China, it has gradually matured and has been gradually applied and promoted in road transport, tractor and other vehicles, and has been widely recognized.

[0005] However, the adaptation problem of the AMT gearbox of the fire truck still needs to be solved, so a control system and strategy for the AMT gearbox of the fire truck is urgently needed to solve this problem. Summary of the invention

[0006] The purpose of the present invention is to provide a control system and method for an AMT transmission of a fire truck, which can realize the gear shifting and automatic clutching of the AMT transmission under different working conditions, accurately control the gear shifting timing and clutch state control, and enhance the gear shifting smoothness and driving experience.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0008] The main structure includes an AMT transmission controller, an engine ECU and a BBM body controller. The AMT transmission controller and the engine ECU are connected via a CAN bus bidirectional data connection, and the engine ECU and the BBM body controller are connected via a CAN bus bidirectional data connection.

[0009] Preferably, the engine ECU is connected to the engine via a CAN bus, the engine ECU is connected to the accelerator pedal via the CAN bus and realizes two-way data communication, the AMT transmission controller is connected to the transmission, the BBM body controller is connected to the power take-off, and the power take-off is connected to a load.

[0010] A gearbox control method comprises the following steps:

[0011] S1: Determine the state of the fire truck. If it is in the driving state, execute step S2; if it is in the operating state, execute step S3;

[0012] S2: The engine ECU collects the accelerator pedal signal and analyzes and processes it to obtain the net output power. The AMT transmission controller analyzes the net output power to determine whether the vehicle should shift up;

[0013] S3: The AMT transmission controller collects the power take-off signal and limits the transmission gear position to ensure that the vehicle is stationary.

[0014] Preferably, step S2 is specifically as follows: the engine ECU enables the engine to maintain the speed and torque required for the driving condition and output the net output power according to the feedback of the accelerator pedal signal; the AMT transmission controller calculates whether there is sufficient power to keep the vehicle moving at a certain acceleration after upshifting according to the obtained net output power and the current road conditions; if so, upshifting is selected; otherwise, upshifting is prohibited; the road conditions specifically include vehicle weight and slope.

[0015] Preferably, the AMT transmission controller calculates whether there is enough power to keep the vehicle moving at a certain acceleration after the gear is upshifted according to the obtained net output power and the current road conditions. Specifically:

[0016] P=N×n / 9550

[0017] Wherein, P is the engine output power, N is the engine output torque, and n is the engine speed;

[0018] Net engine drive power:

[0019] P 净 =PP 阻

[0020] P 阻 =P 滚阻 +P 风阻 +P 坡阻 +P 加速

[0021] Among them, P 阻 P is the power of the vehicle to overcome driving resistance. 滚阻 The power of the vehicle to overcome rolling resistance, P 风阻 P is the power of the vehicle to overcome wind resistance. 坡阻 P is the power of the vehicle to overcome the slope resistance, 加速 To overcome the acceleration resistance power of the whole vehicle.

[0022] Preferably, in order to ensure that the vehicle exerts maximum power during driving, step S2 also includes: the AMT transmission controller collects the engine throttle opening, and when the engine speed leaves the maximum power range, the AMT transmission controller limits the speed from continuing to increase, so that the engine always operates in the maximum power area, thereby improving the vehicle's operating efficiency.

[0023] Preferably, the step S3 is specifically as follows: after the AMT transmission controller collects the power take-off signal, it limits the transmission gear shifting to ensure that the vehicle is stationary; at the same time, when the AMT transmission controller detects that the ambient temperature is relatively low, the AMT transmission controller automatically disengages the clutch and disconnects the transmission after collecting the power take-off signal.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. It solves the problem of how to judge the reasonable gear position required by the fire truck when the automatic transmission fire truck is on emergency duty, avoiding the problem of wrong gear shifting timing, which causes the whole vehicle to shake and be unstable.

[0026] 2. Solved the problem that when the vehicle entered the working mode, the operator did not step on the clutch by mistake, resulting in the power take-off failing to drive the load due to the clutch not being disengaged.

[0027] 3. Solved the problem that when the vehicle exits the operating mode, the load impact of the power take-off is too large, and the gearbox is reversed to cause gear knocking or vehicle malfunction.

[0028] 4. By using the AMT transmission controller, the body control unit BBM, the engine ECU and various signals on the vehicle, the state of the AMT transmission can meet the driving and operation requirements of the fire emergency state. Accurately controlling the transmission can simplify the operator's operating steps, which is easier to operate than the current manual transmission. Using this control method, the service life of the transmission and the service life of the vehicle can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural diagram of the present invention.

[0030] Figure 2 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the application equally.

[0032] Embodiment: A control system and control method for an AMT gearbox of a fire truck

[0033] like Figure 1As shown, in order to realize the fire truck matching AMT gearbox to realize fire emergency driving condition and parking operation power take-off control and engine output speed torque matching control. The control system is realized through the AMT gearbox controller, engine ECU controller, BBM upper control unit through program logic judgment, CAN line signal transmission and output control execution terminal.

[0034] This control method controls the engine speed and torque through the accelerator pedal opening signal. The AMT controller controls the AMT gearbox shift timing and the power take-off operation during working conditions through the judgment logic. The engine ECU and BBM are connected in series through the bus system to achieve the following functions:

[0035] 1. Driving condition logic: The engine ECU uses the accelerator pedal signal feedback to keep the engine at the speed and torque required for the driving condition. The AMT transmission controller calculates whether there is enough power to keep the vehicle moving at a certain acceleration after upshifting based on the net output power and current road conditions (vehicle weight, slope). If so, upshifting is selected; otherwise, upshifting is prohibited.

[0036] The AMT transmission controller calculates whether there is enough power to keep the vehicle moving at a certain acceleration after the gear is upshifted based on the obtained net output power and the current road conditions. Specifically:

[0037] P=N×n / 9550

[0038] Wherein, P is the engine output power, N is the engine output torque, and n is the engine speed;

[0039] Net engine drive power:

[0040] P 净 =PP 阻

[0041] P 阻 =P 滚阻 +P 风阻 +P 坡阻 +P 加速

[0042] Among them, P 阻 P is the power of the vehicle to overcome driving resistance. 滚阻 The power of the vehicle to overcome rolling resistance, P 风阻 P is the power of the vehicle to overcome wind resistance. 坡阻 P is the power of the vehicle to overcome the slope resistance, 加速 To overcome the acceleration resistance power of the whole vehicle.

[0043] At the same time, in order to ensure that the vehicle can exert its maximum power during driving, the AMT transmission controller will write the engine throttle opening response characteristics into the program. When the engine speed leaves the maximum power range, the AMT transmission controller limits the speed to continue to increase, so that the engine always works in the maximum power area, improving the vehicle's operating efficiency. The speed and torque of the transmission and engine are adapted to the rapid acceleration and high torque of the fire truck's emergency response.

[0044] 2. Operation condition logic: When the vehicle is parked and working in place, in order to ensure the safety of the vehicle, the AMT transmission controller will limit the transmission gear selection after receiving the power take-off signal, and distribute the braking force to each wheel by sending a control signal to the ABS controller to ensure that the vehicle is stationary.

[0045] Based on the control of ambient temperature, the AMT transmission controller detects that the ambient temperature is relatively low, the transmission oil will be relatively viscous and the resistance will be greater. In order to reduce the power diversion at the transmission end and save energy, the AMT transmission controller automatically disengages the clutch and disconnects the transmission after detecting the power take-off signal.

[0046] According to the working status and load conditions, the execution end transmits the speed and torque requirements to the engine ECU through the CAN signal of the body control unit BBM. The engine ECU determines the load feedback and drives the AMT transmission controller to drive the power take-off to drive the load such as the fire pump and other terminal operations according to the program control logic.

Claims

1. A gearbox control method for a control system of an AMT gearbox of a fire truck, characterized in that: The control system of the AMT gearbox includes: an AMT gearbox controller, an engine ECU and a BBM body controller, the AMT gearbox controller and the engine ECU are connected by a CAN bus bidirectional data connection, the engine ECU and the BBM body controller are connected by a CAN bus bidirectional data connection, the engine ECU is connected to the engine via the CAN bus, the engine ECU is connected to the accelerator pedal via the CAN bus and realizes bidirectional data communication, the AMT gearbox controller is connected to the gearbox, the BBM body controller is connected to a power take-off, and the power take-off is connected to a load; The control method comprises the following steps: S1: Determine the state of the fire truck. If it is in the driving state, execute step S2; if it is in the operating state, execute step S3; S2: The engine ECU collects the accelerator pedal signal and analyzes and processes it to obtain the net output power. The AMT transmission controller analyzes the net output power to determine whether the vehicle should shift up; S3: The AMT transmission controller collects the power take-off signal and limits the transmission gear position to ensure that the vehicle is stationary; The AMT transmission controller calculates whether there is enough power to keep the vehicle moving at a certain acceleration after the gear is upshifted based on the obtained net output power and the current road conditions. Specifically: in, is the engine output power, The engine output torque is is the engine speed; Net engine drive power: in, To overcome the driving resistance power of the vehicle, To overcome the rolling resistance of the vehicle, To overcome the wind resistance of the vehicle, To overcome the slope resistance power of the vehicle, To overcome the acceleration resistance power of the whole vehicle.

2. A transmission control method according to claim 1, characterized in that: The step S2 is specifically as follows: the engine ECU enables the engine to maintain the speed and torque required for the driving condition and output the net output power according to the feedback of the accelerator pedal signal; the AMT transmission controller calculates whether there is enough power to keep the vehicle moving at a certain acceleration after upshifting according to the obtained net output power and the current road conditions; if so, upshifting is selected; otherwise, upshifting is prohibited; the road conditions specifically include vehicle weight and slope.

3. A transmission control method according to claim 2, characterized in that: To ensure that the vehicle exerts maximum power during driving, step S2 also includes: the AMT transmission controller collects the engine throttle opening. When the engine speed leaves the maximum power range, the AMT transmission controller limits the speed from continuing to increase, so that the engine always operates in the maximum power area, thereby improving the vehicle's operating efficiency.

4. A transmission control method according to claim 1, characterized in that: The step S3 is specifically as follows: after the AMT transmission controller collects the power take-off signal, it limits the transmission gear shifting to ensure that the vehicle is stationary; at the same time, when the AMT transmission controller detects that the ambient temperature is relatively low, the AMT transmission controller automatically disengages the clutch and disconnects the transmission after collecting the power take-off signal.

Images