A heavy truck adaptive cab suspension control system and method

Abstract

The present application belongs to the field of truck cab damping, and discloses a heavy truck adaptive cab suspension control system and method, which comprises a displacement sensor (1), a controller (2) and an adjustable damping shock absorber (3); a plurality of adjustable damping shock absorbers (3) are connected with the controller (2) in parallel, the displacement sensor (1) is used for collecting cab motion response signals and inputting the signals into the controller (2); the controller (2) collects vehicle operating parameters when the vehicle is running through a CAN bus, pre-processes the collected parameters, and outputs a calibrated current to the adjustable damping shock absorber. The displacement sensor can accurately obtain the displacement of the suspension, the differential of the displacement can accurately obtain the motion speed and displacement of the suspension, and the motion condition of the cab suspension can be accurately judged according to the speed and displacement information, so as to adjust the cab suspension system to a suitable damping force value.

Description

Technical Field

[0001] This invention belongs to the field of truck cab vibration reduction, and particularly relates to a heavy-duty truck adaptive cab suspension control system and method. Background Technology

[0002] Heavy-duty trucks typically employ chassis suspension and cab mounting systems to attenuate road vibrations, with the cab mounting system's damping performance being crucial for driving comfort. Therefore, improving the damping performance of the cab mounting system is an effective way to enhance driver comfort. Currently, heavy-duty truck cab mounting systems use a traditional passive damping method combining springs and shock absorbers. Once the damping system parameters are determined, it can only passively respond to transmitted vibrations and cannot adapt to the varying requirements of different road conditions. Domestic road conditions are complex, with heavy-duty trucks operating on highways, national roads, provincial roads, and even lower-grade county roads and unpaved surfaces. Traditional damping cab mounting systems are no longer adequate for the demands of heavy-duty trucks operating under complex and changing conditions. The market urgently needs a cab mounting system with adaptive damping adjustment to ensure the vehicle is always in optimal damping condition and improve vehicle comfort.

[0003] Passenger car chassis suspension systems and cab suspension systems share many technical similarities. Adjustable damping suspension systems are already used in many mid-to-high-end passenger cars. Existing suspension damping adjustment technology mainly employs a semi-active damping force control method. This involves using acceleration sensors to collect the road surface excitation on the suspension, employing a relatively complex control strategy based on the excitation, calculating the required damping value for the vehicle through a controller, and finally adjusting the damping force through adjustable damping shock absorbers. Since one end of the suspension is in contact with the road surface and the other end is connected to the cab, the road surface can be considered stationary. Therefore, the suspension's speed and displacement can be obtained simply by integrating the acceleration signals acquired by the acceleration sensors mounted on the suspension. The cab suspension system is connected to the chassis at one end and the cab at the other. Therefore, to obtain the cab suspension displacement, similar to the semi-active suspension design used in passenger cars, acceleration sensors need to be installed on both sides of the chassis and the cab. The speed and displacement of the suspension can only be obtained by integrating and subtracting the two acceleration signals. This presents two problems. First, the cost of two accelerometers is high. Second, the integration of acceleration signals to obtain velocity and displacement data itself has a large deviation. If the two acceleration signals are integrated separately and then subtracted to obtain velocity and displacement data, the integration error of the two signals will accumulate, and the deviation of the final velocity and displacement data will not meet the needs of engineering applications.

[0004] Similar cab suspension damping control schemes use collected sensor data to determine the vehicle's driving state and then calculate the required damping force for the shock absorbers based on that state. However, because the sensors collect signals from the vehicle's already exhibited response state, they cannot obtain driver input and provide controller commands before the vehicle responds in an emergency, thus failing to pre-determine the required cab suspension damping force. Consequently, vehicle comfort and safety cannot be adequately guaranteed. Summary of the Invention

[0005] The technical problem this invention aims to solve is that: the cab suspension speed and displacement calculated by multiple acceleration sensors through one or two integrations have large deviations, making them unsuitable for engineering applications; in emergency situations, it is impossible to obtain the driver's operating actions and issue controller commands before the vehicle responds, thus failing to provide the required cab suspension damping force value in advance, and consequently, the vehicle's comfort and safety cannot be well guaranteed.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0007] A heavy-duty truck adaptive cab suspension control system includes a displacement sensor 1, a controller 2, and an adjustable damping shock absorber 3; multiple adjustable damping shock absorbers 3 connected in parallel are connected to the controller 2; the displacement sensor 1 is used to collect the cab motion response signal and input it to the controller 2; the controller 2 collects vehicle operating parameters during vehicle operation via a CAN bus, preprocesses the collected parameters, and outputs a calibrated current to the adjustable damping shock absorber.

[0008] Preferably, the number of adjustable damping shock absorbers 3 is 4.

[0009] Preferably, the number of displacement sensors 1 is 4.

[0010] This invention also provides a control method for a heavy-duty truck adaptive cab suspension system. This method is based on the aforementioned heavy-duty truck adaptive cab suspension control system and specifically includes the following steps:

[0011] Step 1: After activating the adaptive cab suspension system, determine whether the power supply, communication, and various components of the adaptive cab suspension system are normal: determine whether it can communicate with the vehicle via CAN to obtain signals such as vehicle speed, steering wheel angle, and braking pressure, and whether it can obtain suspension displacement signals through displacement sensor signals;

[0012] Step 2: Determine if the system is working: When the vehicle speed is less than the minimum vehicle speed V0 required for the adaptive control system to start, the system does not work and does not output current to the adjustable damping shock absorber. The adjustable damping shock absorber will output the basic damping force value according to the inherent characteristics of the shock absorber structure. When the vehicle speed is greater than V0, the system works and proceeds to Step 3.

[0013] Step 3: Operating Condition Identification and Judgment

[0014] When the steering wheel angular velocity is greater than or equal to the minimum steering wheel angular velocity R required to trigger the steering condition, the system performs emergency steering mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force according to the preset combination of steering damping force values ​​to reduce the vehicle's roll vibration amplitude.

[0015] When the brake cylinder pressure is greater than or equal to the minimum brake cylinder pressure P required to trigger the braking condition, the system performs braking mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force according to the preset damping force value for suppressing pitch, thereby reducing the pitch vibration amplitude of the vehicle.

[0016] When the cab suspension movement speed v calculated by the displacement sensor is less than the critical speed V1 of the damper for switching to good road mode, the system performs good road mode control. The controller sends a current signal to the adjustable damping damper, and the four adjustable damping dampers output damping force in combination according to the preset smaller damping force value to reduce the vertical vibration amplitude of the vehicle.

[0017] When V1≤cab suspension movement speed v calculated by displacement sensor < damper critical speed V2 for bad road mode switching, the system performs standard mode control. The controller sends current signal to the adjustable damping damper, and the four adjustable damping dampers output damping force according to the preset medium damping force value combination to reduce the vertical vibration amplitude of the vehicle.

[0018] When V2 ≤ the cab suspension movement speed v calculated by the displacement sensor, the system performs bad road mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force in combination according to the preset larger damping force value to reduce the vertical vibration amplitude of the vehicle.

[0019] When the system malfunctions or does not enter the above modes, the system will not output current to the adjustable damping shock absorber. The adjustable damping shock absorber will output the basic damping force value according to the inherent characteristics of the shock absorber structure, ensuring that the cab suspension system has basic vibration damping performance.

[0020] This invention has the following advantages: The displacement sensor can accurately obtain the suspension displacement; by differentiating the displacement, the movement speed and displacement of the suspension can be accurately obtained; and based on the speed and displacement information, the movement of the cab suspension can be accurately determined, thereby adjusting the cab suspension system to a suitable damping force value. This avoids the problem of large deviations in the cab suspension speed and displacement calculated by using multiple acceleration sensors through one or two integrations, which makes it unsuitable for engineering applications. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the heavy-duty truck adaptive cab suspension control system of the present invention;

[0022] Figure 2 This is a schematic diagram of the control method for the adaptive cab suspension system of heavy-duty trucks according to the present invention. Detailed Implementation

[0023] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, the adaptive suspension control system of this invention mainly consists of a displacement sensor, a controller, and an adjustable damping shock absorber. When the vehicle is in motion, vehicle operating parameters are input to the controller via CAN bus and cable. The cab motion response signal collected by the displacement sensor is also input to the controller. The controller preprocesses the collected signals (differentiating the steering wheel angle signal to obtain the steering wheel angular velocity, and differentiating the cab suspension displacement signal to obtain the cab suspension motion speed). The controller makes judgments based on the pre-set control logic and outputs a calibrated current to the adjustable damping shock absorber to achieve the required damping force combination, thus ensuring the system has the best vibration reduction effect.

[0025] like Figure 2 As shown, the present invention also provides a control method for an adaptive cab suspension system for heavy-duty trucks, which specifically includes the following steps:

[0026] Step 1: After activating the adaptive cab suspension system, determine whether the power supply, communication, and components of the adaptive cab suspension system are normal: determine whether it can communicate with the vehicle via CAN to obtain signals such as vehicle speed, steering wheel angle, and braking pressure, and whether it can obtain suspension displacement signals through displacement sensor signals.

[0027] Step 2: Determine if the system is working: When the vehicle speed is less than V0 (the minimum vehicle speed at which the adaptive control system starts), the system does not work and does not output current to the adjustable damping shock absorber. The adjustable damping shock absorber will output the basic damping force value according to the inherent characteristics of the shock absorber structure. When the vehicle speed is greater than V0, the system works and proceeds to step 3.

[0028] Step 3, Operating Condition Identification and Judgment:

[0029] When the steering wheel angular velocity is greater than or equal to R (the minimum steering wheel angular velocity that triggers the steering condition), the system performs emergency steering mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force according to the preset combination of steering damping force values ​​to reduce the vehicle roll vibration amplitude.

[0030] When the brake cylinder pressure is ≥ P (the minimum brake cylinder pressure required to trigger braking), the system performs braking mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force according to the preset damping force value for suppressing pitch, thereby reducing the pitch vibration amplitude of the vehicle.

[0031] When the cab suspension movement speed v calculated by the displacement sensor is less than V1 (the critical speed of the damper when switching to good road mode), the system performs good road mode control. The controller sends a current signal to the adjustable damping damper, and the four adjustable damping dampers output damping force in combination according to the preset smaller damping force value to reduce the vertical vibration amplitude of the vehicle.

[0032] When the cab suspension movement speed V1≤v<V2 (the critical speed of the shock absorber when switching to bad road mode) is calculated based on the displacement sensor, the system performs standard mode control. The controller sends a current signal to the adjustable damping shock absorber, and the four adjustable damping shock absorbers output damping force in combination according to the preset medium damping force value to reduce the vertical vibration amplitude of the vehicle.

[0033] When the cab suspension movement speed V2 ≤ v calculated by the displacement sensor, the system performs bad road mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force in combination according to the preset larger damping force value, thereby reducing the vertical vibration amplitude of the vehicle.

[0034] When the system malfunctions or does not enter the above modes, the system will not output current to the adjustable damping shock absorber. The adjustable damping shock absorber will output the basic damping force value according to the inherent characteristics of the shock absorber structure, ensuring that the cab suspension system has basic vibration damping performance.

[0035] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art will be able to make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. A heavy-duty truck adaptive cab suspension control system, characterized in that, It includes a displacement sensor (1), a controller (2), and an adjustable damping shock absorber (3); multiple adjustable damping shock absorbers (3) arranged in parallel are connected to the controller (2), the displacement sensor (1) is used to collect the cab motion response signal and input it to the controller (2); the controller (2) collects the vehicle operating parameters when the vehicle is driving through the CAN bus, preprocesses the collected parameters, and outputs the calibrated current to the adjustable damping shock absorber; The control method of this control system includes the following steps: Step 1: After activating the adaptive cab suspension system, determine whether the power supply, communication, and various components of the adaptive cab suspension system are normal: determine whether it can communicate with the vehicle via CAN to obtain vehicle speed, steering wheel angle, and brake pressure signals, and whether it can obtain suspension displacement signals through displacement sensor signals; Step 2: Determine if the system is working: When the vehicle speed is less than the minimum vehicle speed V0 required for the adaptive control system to start, the system does not work and does not output current to the adjustable damping shock absorber. The adjustable damping shock absorber will output the basic damping force value according to the inherent characteristics of the shock absorber structure. When the vehicle speed is greater than V0, the system works and proceeds to Step 3. Step 3: Operating Condition Identification and Judgment When the steering wheel angular velocity is greater than or equal to the minimum steering wheel angular velocity R required to trigger the steering condition, the system performs emergency steering mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force according to the preset combination of steering damping force values ​​to reduce the vehicle's roll vibration amplitude. When the brake cylinder pressure is greater than or equal to the minimum brake cylinder pressure P required to trigger the braking condition, the system performs braking mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force according to the preset damping force value for suppressing pitch, thereby reducing the pitch vibration amplitude of the vehicle. When the cab suspension movement speed v calculated by the displacement sensor is less than the critical speed V1 of the damper for switching to good road mode, the system performs good road mode control. The controller sends a current signal to the adjustable damping damper, and the four adjustable damping dampers output damping force in combination according to the preset smaller damping force value to reduce the vertical vibration amplitude of the vehicle. When V1≤cab suspension movement speed v calculated by displacement sensor < damper critical speed V2 for bad road mode switching, the system performs standard mode control. The controller sends current signal to the adjustable damping damper, and the four adjustable damping dampers output damping force according to the preset medium damping force value combination to reduce the vertical vibration amplitude of the vehicle. When V2 ≤ the cab suspension movement speed v calculated by the displacement sensor, the system performs bad road mode control. The controller sends a current signal to the adjustable damping shock absorbers, and the four adjustable damping shock absorbers output damping force in combination according to the preset larger damping force value to reduce the vertical vibration amplitude of the vehicle. When the system malfunctions or does not enter the above modes, the system will not output current to the adjustable damping shock absorber. The adjustable damping shock absorber will output the basic damping force value according to the inherent characteristics of the shock absorber structure, ensuring that the cab suspension system has basic vibration damping performance.

2. The heavy-duty truck adaptive cab suspension control system according to claim 1, characterized in that, The number of displacement sensors (1) is 4.

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