Electric control device for continuously adjustable semi-active suspension of vehicle and its control method

Abstract

The present invention discloses an electronic control device and method for an automotive damping continuously adjustable semi-active suspension, which is used to control a shock absorber solenoid valve arranged at the body suspension position, and includes: a collection unit, which is used to collect a body vertical height signal and a body vertical acceleration signal including the suspension position; a control unit, which provides a control signal for the shock absorber solenoid valve according to the body vertical height signal and the body vertical acceleration signal of the suspension position; a solenoid valve drive circuit, through which the control unit controls the shock absorber solenoid valve; a plurality of current feedback circuits, which are connected to the control unit through an A / D conversion unit, and feedback the current of the shock absorber solenoid valve to the control unit to correct the error of the drive current of the shock absorber solenoid valve drive circuit. The present invention solves the technical problem between the ride comfort and handling stability of an automobile.

Description

Technical Field

[0001] The present invention relates to the field of automotive continuously variable damping semi-active suspensions, and particularly to an electronic control device and a control method for an automotive solenoid valve-controlled continuously variable damping semi-active suspension. Background Art

[0002] The suspension system can improve the ride comfort and handling stability of an automobile. The continuously variable damping semi-active suspension solves the technical defect that the damping of a passive suspension cannot be adjusted, can independently track the damping force demand signal, and can continuously adjust the damping force to any point in the damping working area. Currently, the continuously variable damping semi-active suspension is mainly divided into two types: magnetorheological (or electrorheological) and solenoid valve-controlled. Among them, the solenoid valve-controlled continuously variable damping semi-active suspension has the advantages of simple structure, rapid response, reliable performance, and low development cost, and has great technical advantages and market potential.

[0003] The solenoid valve-controlled continuously variable damping semi-active suspension needs to take into account both the ride comfort and handling stability of the automobile, and adaptively adjust the damping forces of the four semi-active suspensions according to road conditions, driving conditions, and driver requirements. This puts higher requirements on the electronic control device and control method of the continuously variable damping semi-active suspension. Therefore, it is of great value to design and develop a damping electronic control device and control method with low cost, high precision, reliable performance, and capable of multiple-mode adjustment. Summary of the Invention

[0004] It should be understood that the above general description and the following detailed description of the present disclosure are both exemplary and explanatory, and are intended to provide further explanation of the present disclosure as claimed.

[0005] In view of the above problems, the present invention provides an electronic control device and a control method for real-time dynamic control of an automotive continuously variable damping semi-active suspension.

[0006] The present invention discloses an electronic control device for an automotive continuously variable damping semi-active suspension, which is used to control a shock absorber solenoid valve arranged at the body suspension position, and is characterized by comprising:

[0007] An acquisition unit for acquiring a body vertical height signal and a body vertical acceleration signal including the suspension position;

[0008] A control unit for providing a control signal for the shock absorber solenoid valve according to the body vertical height signal and the body vertical acceleration signal of the suspension position;

[0009] A solenoid valve drive circuit, and the control unit controls the shock absorber solenoid valve through the solenoid valve drive circuit;

[0010] A number of current feedback circuits are connected to the control unit through an A / D conversion unit, feeding back the current of the shock absorber solenoid valve to the control unit to correct the error of the driving current of the shock absorber solenoid valve driving circuit.

[0011] Preferably, an electronic control device for a continuously adjustable semi-active suspension of an automobile further disclosed by the present invention is characterized in that

[0012] The acquisition unit acquires the vertical body height signal of the suspension position through its PWM peripheral interface.

[0013] Preferably, an electronic control device for a continuously adjustable semi-active suspension of an automobile further disclosed by the present invention is characterized in that

[0014] The vertical body height signal and the vertical body acceleration signal are respectively provided by three groups of body sensors located at three suspension positions, and the control unit obtains the vertical body height signal and the vertical body acceleration signal of the fourth suspension position accordingly.

[0015] Preferably, an electronic control device for a continuously adjustable semi-active suspension of an automobile further disclosed by the present invention is characterized in that

[0016] The control unit controls the solenoid valve driving circuit through the PWM output port.

[0017] Preferably, an electronic control device for a continuously adjustable semi-active suspension of an automobile further disclosed by the present invention is characterized in that

[0018] The control unit includes a PSI5 peripheral sensing interface, and reads the signal sent by the vertical body acceleration sensor through the PSI5 peripheral sensing interface.

[0019] Preferably, an electronic control device for a continuously adjustable semi-active suspension of an automobile further disclosed by the present invention is characterized in that

[0020] The control unit further receives a mode selection and controls accordingly, and the mode selection includes one of a standard type, a sport type, and a comfort type.

[0021] Preferably, an electronic control device for a continuously adjustable semi-active suspension of an automobile further disclosed by the present invention is characterized in that

[0022] The electromagnetic drive circuit adopts a high and low side combined drive mode, and simultaneously controls two MOSFET circuits of the high side and the low side through a MOSFET drive chip to ensure the response of the shock absorber solenoid valve.

[0023] The present invention also discloses a control method for an automotive continuously variable damping semi-active suspension, which is characterized by comprising:

[0024] Step 1, initialization;

[0025] Step 2, obtaining the body vertical height and body vertical acceleration including the mode signal and the three suspension positions;

[0026] Step 3, obtaining the fourth body vertical height and body vertical acceleration according to the three body vertical heights and body vertical accelerations;

[0027] Step 4, performing sub-task control for different operating states of the whole vehicle, including uniform motion, acceleration, braking, steering and instability, including body vertical vibration control, body pitch control, body roll control, wheel vertical vibration control and vehicle instability control;

[0028] Step 5, judging the operating state of the whole vehicle through threshold according to the decision parameters, switching the sub-tasks including vertical vibration control, pitch attitude control, roll attitude control and instability control in a priority manner, and obtaining the final decision current;

[0029] Step 6, converting the decision current into the corresponding PWM output, collecting the actual current value of the corresponding solenoid valve through the current feedback circuit, and using the current value after error correction to control the continuously variable damping shock absorber solenoid valve.

[0030] Preferably, the present invention further discloses a control method for an automotive continuously variable damping semi-active suspension, which is characterized in that

[0031] The three suspension positions in Step 2 include the left front, right front and left rear suspension positions;

[0032] In Step 3, the fourth suspension position includes the right rear suspension, the body vertical speed thereof is obtained according to the body vertical speed at the right front suspension according to the vehicle speed and wheelbase information, and the relative movement speed thereof is obtained according to the relative movement speeds at the right front and left rear suspensions.

[0033] Preferably, the present invention further discloses a control method for an automotive continuously variable damping semi-active suspension, which is characterized in that

[0034] In Step 4, it further includes:

[0035] The system modes include standard, sport and comfort. The comfort mode adopts skyhook control with adjustable gain, the sport mode adopts groundhook control with adjustable gain, and the standard mode adopts improved skyhook control with adjustable gain.

[0036] The present invention can propose an electronic control device and a control method for a continuously adjustable semi-active suspension of an automobile based on two types of signals from a vehicle body vertical acceleration sensor and a vehicle body height sensor, and perform dynamic real-time control on four continuously adjustable shock absorbers, thereby solving the technical problem between the ride comfort and handling stability of the automobile. Description of the Drawings

[0037] Embodiments of the present disclosure will now be described in detail with reference to the drawings. Preferred embodiments of the present disclosure will now be described in detail, and examples thereof are shown in the drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. In addition, although the terms used in the present disclosure are selected from well-known and commonly used terms, some of the terms mentioned in the description of the present disclosure may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of the present description. In addition, it is required to understand the present disclosure not only by the actual terms used, but also by the meaning implied by each term.

[0038] Below, with reference to the drawings, for those skilled in the technical field, from the detailed description of the present invention, the above and other objects, features and advantages of the present invention will be apparent.

[0039] Figure 1 It is a circuit principle block diagram of the electronic control device of the present invention;

[0040] Figure 2 It is a power supply circuit schematic diagram of the electronic control device of the present invention;

[0041] Figure 3 It is a CAN communication module circuit schematic diagram of the electronic control device of the present invention;

[0042] Figure 4 It is a left front suspension solenoid valve drive circuit schematic diagram of the electronic control device of the present invention;

[0043] Figure 5 It is a boost circuit schematic diagram of the electronic control device of the present invention;

[0044] Figure 6 It is a left front suspension solenoid valve drive current feedback circuit schematic diagram of the electronic control device of the present invention;

[0045] Figure 7 It is a high-frequency signal processing circuit schematic diagram of the electronic control device of the present invention;

[0046] Figure 8 It is a left front suspension height sensor filtering circuit schematic diagram of the electronic control device of the present invention;

[0047] Figure 9 It is a flowchart of the control method of the present invention.

[0048] Reference Signs

[0049] 1 - Electronic control device

[0050] 2 - Microprocessor

[0051] 3 - Power supply circuit

[0052] 4 - CAN communication module

[0053] 5 - Left front suspension (FL) solenoid valve drive circuit

[0054] 6 - Left front suspension (FL) current feedback circuit

[0055] 7 - Right front suspension (FR) solenoid valve drive circuit

[0056] 8 - Right front suspension (FR) current feedback circuit

[0057] 9 - Left rear suspension (RL) solenoid valve drive circuit

[0058] 10 - Left rear suspension (RL) current feedback circuit

[0059] 11 - Right rear suspension (RR) solenoid valve drive circuit

[0060] 12 - Right rear suspension (RR) current feedback circuit

[0061] 13 - BDM interface circuit

[0062] 14 - Clock circuit

[0063] 15 - Reset circuit

[0064] 16 - Body vertical acceleration high-frequency signal processing circuit

[0065] 17 - Right rear suspension (RL) height sensor signal filtering circuit

[0066] 18 - Right front suspension (FR) height sensor signal filtering circuit

[0067] 19 - Left front suspension (FL) height sensor signal filtering circuit

[0068] 20 - Voltage division circuit

[0069] 21 - Mode switch

[0070] 22 - Body height sensor at the left front suspension (FL)

[0071] 23 - Body height sensor at the right front suspension (FR)

[0072] 24 - Body height sensor at the left rear suspension (RL)

[0073] 25 - Body vertical acceleration sensor at the left front suspension (FL)

[0074] 26 - Body vertical acceleration sensor at the right front suspension (FR)

[0075] 27 - Body vertical acceleration sensor at the left rear suspension (RL)

[0076] 28 - Shock absorber solenoid valve at the left front suspension (FL)

[0077] 29 - Shock absorber solenoid valve at the right front suspension (FR)

[0078] 30 - Shock absorber solenoid valve at the left rear suspension (RL)

[0079] 31 - Shock absorber solenoid valve at the right rear suspension (RR) Detailed implementation mode

[0080] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0081] As shown in the present application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one" and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0082] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the orientation or positional relationships shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0083] For ease of description, spatial relative terms, such as "above", "over", "on the upper surface", "upper", etc., may be used herein to describe the spatial positional relationship of one device or feature shown in the figures with other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "beneath" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations of the spatial relative descriptions used herein will be made.

[0084] In addition, it should be noted that the use of terms such as "first", "second", etc. to define components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present application. In addition, although the terms used in the present application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of the present description. In addition, it is required to understand the present application not only through the actual terms used, but also through the meanings implied by each term.

[0085] To solve the above technical problems, the present invention provides an electronic control device for an automotive damping continuously adjustable semi-active suspension, which includes a microprocessor, a power supply circuit, a CAN communication module, a semi-active suspension solenoid valve drive circuit, an output current feedback circuit, a BDM debugging circuit, a clock circuit, a reset circuit, a vehicle body vertical acceleration high-frequency signal processing circuit, a vehicle body height sensor signal filtering circuit, and a voltage dividing circuit. The input signals of the electronic control device come from a mode switch, a vehicle body height sensor, and a vehicle body vertical acceleration sensor. The output signals of the electronic control device are used to control the solenoid valves of four damping continuously adjustable semi-active suspension shock absorbers, so as to realize the continuous variable adjustment of the damping force of the automotive semi-active suspension.

[0086] Among them, the microprocessor is the core component of the electronic control device of the present invention. In addition to the necessary computing speed to ensure the real-time operation of the control algorithm, it also needs to have four PWM duty cycle output ports to control the output current of the drive circuit, and the driving ability of each path is not less than 1.6A; four ATD sampling interfaces to receive the solenoid valve control current feedback; three PWM sampling ports to read the signals sent by the vehicle body height sensor with a PWM peripheral interface; three PSI5 standard sampling interfaces to read the signals sent by the vehicle body vertical acceleration sensor that conforms to the PSI5 peripheral sensing interface; at least one high-speed CAN interface (500Kbps) is required for communication with the vehicle CAN bus.

[0087] The present invention will be further described below through specific embodiments in conjunction with the drawings.

[0088] As Figure 1 shown is the circuit principle block diagram of the electronic control device of the present invention.

[0089] The present invention provides an electronic control device 1 for an automotive damping continuously adjustable semi-active suspension.

[0090] Among them, the microprocessor 2 is the core component of the electronic control device of the present invention. In addition to the necessary computing speed to ensure the real-time operation of the control algorithm, it also needs to have four PWM duty cycle output ports to control the output current of the drive circuit, and the driving ability of each path is not less than 1.6A; four ATD sampling interfaces to receive the solenoid valve control current feedback; three PWM sampling ports to read the signals sent by the vehicle body height sensor with a PWM peripheral interface; three PSI5 standard sampling interfaces to read the signals sent by the vehicle body vertical acceleration sensor that conforms to the PSI5 peripheral sensing interface; at least one high-speed CAN interface (500Kbps) is required for communication with the vehicle CAN bus.

[0091] Figure 1 In, the input signals of the electronic control device 1 come from the mode switch 21, the vehicle body height sensor 22 at the left front suspension (FL), the vehicle body height sensor 23 at the right front suspension (FR), the vehicle body height sensor 24 at the left rear suspension (RL), the vehicle body vertical acceleration sensor 25 at the left front suspension (FL), the vehicle body vertical acceleration sensor 26 at the right front suspension (FR), and the vehicle body vertical acceleration sensor 27 at the left rear suspension (RL).

[0092] Among them, the vehicle body height sensors 22 at the left front suspension (FL), the vehicle body height sensors 23 at the right front suspension (FR), and the vehicle body height sensors 24 at the left rear suspension (RL) respectively transmit the vehicle body height signals to the microprocessor 2 through the left front suspension (FL) height sensor signal filtering circuit 19, the right front suspension (FR) height sensor signal filtering circuit 18, and the right rear suspension (RL) height sensor signal filtering circuit 17.

[0093] Among them, the vehicle body vertical acceleration sensors 25 at the left front suspension (FL), the vehicle body vertical acceleration sensors 26 at the right front suspension (FR), and the vehicle body vertical acceleration sensors 27 at the left rear suspension (RL) are transmitted to the microprocessor 2 through the vehicle body vertical acceleration high-frequency signal processing circuit 16.

[0094] In addition, the electronic control device 1 also employs a mode switch 21, which transmits the mode selection signal to the microprocessor 2 through the voltage dividing circuit 20.

[0095] The output signal of the electronic control device 1 of the present invention is used to control the left front suspension (FL) shock absorber solenoid valve 28, the right front suspension (FR) shock absorber solenoid valve 29, the left rear suspension (RL) shock absorber solenoid valve 30, and the right rear suspension (RR) shock absorber solenoid valve 31.

[0096] The output of the microprocessor 2 of the electronic control device 1 drives the left front suspension (FL) shock absorber solenoid valve 28, the right front suspension (FR) shock absorber solenoid valve 29, the left rear suspension (RL) shock absorber solenoid valve 30, and the right rear suspension (RR) shock absorber solenoid valve 31 respectively through the left front suspension (FL) solenoid valve drive circuit 5, the right front suspension (FR) solenoid valve drive circuit 7, the left rear suspension (RL) solenoid valve drive circuit 9, and the right rear suspension (RR) solenoid valve drive circuit 11. At the same time, the left front suspension (FL) current feedback circuit 6, the right front suspension (FR) current feedback circuit 8, the left rear suspension (RL) current feedback circuit 10, and the right rear suspension (RR) current feedback circuit 12 feedback the currents of the four solenoid valves back to the microprocessor 2.

[0097] Among them, the semi-active suspension solenoid valve drive circuit includes the left front suspension (FL) solenoid valve drive circuit 5, the right front suspension (FR) solenoid valve drive circuit 7, the left rear suspension (RL) solenoid valve drive circuit 9, and the right rear suspension (RR) solenoid valve drive circuit 11, which respectively amplify the power of the four-way PWM control signals output by the microprocessor 2 to drive the corresponding four semi-active suspension solenoid valves 28 - 31 to work, realizing continuous variable adjustment of the shock absorber damping force; these four drive circuits adopt the high and low side combined drive method to ensure the fast response of the solenoid valve.

[0098] Surrounding the microprocessor 2 also include a power supply circuit 3, a CAN communication module 4, a BDM debugging interface circuit 13, a clock circuit 14, and a reset circuit 15.

[0099] Among them, the CAN communication module 4 is used to realize data interaction between the electronic control device of the present invention and other electronic control devices in the vehicle, read vehicle signals such as vehicle speed, longitudinal acceleration, and yaw rate in real time, and send the operation information of the electronic control device of the present invention to the instrument panel for display.

[0100] The BDM debugging interface circuit 13, the clock circuit 14, and the external reset circuit 15 are peripheral circuits to support the operation of the microprocessor 2, and are respectively used for background debugging of the microprocessor, clock signal generation, and external reset.

[0101] In a preferred embodiment, the present invention uses the MC9S12XEP100 chip in the S12X series of NXP Semiconductor. The on-chip FLASH memory capacity reaches 1MB, supports a maximum external clock frequency of 50M, and has rich interfaces. It can provide an analog-to-digital conversion A / D channel with a maximum precision of 16 bits, 4 high-speed CAN channels, 8 8-bit PWM output channels, 8 enhanced capture timer ECT sampling channels, and 8 TIM acquisition channels, meeting the functional requirements of the damping continuously adjustable semi-active suspension electronic control device proposed by the present invention.

[0102] Figure 2 The schematic diagram of the power supply circuit 3 of the present invention is shown.

[0103] The power supply circuit 3 is one of the essential circuits of the electronic control device of the present invention. The power supply voltage of the above-mentioned microprocessor 2 and other peripheral circuits is 5V. The power supply circuit 3 is required to convert the vehicle-mounted 12V voltage into 5V and maintain the stability of the 5V power supply voltage. This power supply circuit decouples, chokes, and stabilizes the vehicle-mounted 12V power signal, eliminates the volatility of the vehicle-mounted power voltage, and reduces the 12V vehicle-mounted power supply to 5V or 8V to meet the power supply requirements of other circuits.

[0104] In Figure 2 , the pin P1 is connected to the vehicle ignition switch, the pin P2 is connected to the vehicle-mounted 12V power supply, and components such as the rectifier diode U1, diode D1, capacitor C1, capacitor C2, capacitor C7, capacitor C8, magnetic rod L1, and magnetic rod L2 are used to decouple, choke, and stabilize the power signal, eliminating the volatility of the vehicle-mounted power voltage.

[0105] The present invention uses a voltage regulator chip LM7805 to reduce the regulated 12V power signal to 5V. The pin P3 is a 5V voltage source controlled by the ignition switch, and the pins P4 and P5 are powered in parallel to improve the driving ability of the 5V voltage source.

[0106] Figure 3The CAN communication module 4 built according to the present invention is shown as follows.

[0107] The CAN communication module 4 is used to realize the data interaction between the electronic control device of the present invention and other electronic control devices of the vehicle, read vehicle signals such as vehicle speed, longitudinal acceleration, and yaw rate in real time, and send the operation information of the electronic control device of the present invention to the instrument panel for display.

[0108] The high-speed CAN transceiver U8 uses the TJA1050 chip. Among them, the RXD and TXD pins of the CAN transceiver U8 are connected to the PM0 and PM1 interfaces of the microprocessor 2, and the CANH and CANL pins of the CAN transceiver U8 are connected to the vehicle CAN bus, that is Figure 3 the identification lines 33 and 34 in

[0109] Figure 4 The schematic diagram of the left front suspension solenoid valve drive circuit 5 of the present invention is shown as follows.

[0110] Figure 1 The left front suspension (FL) solenoid valve drive circuit 5, the right front suspension (FR) solenoid valve drive circuit 7, the left rear suspension (RL) solenoid valve drive circuit 9, and the right rear suspension (RR) solenoid valve drive circuit 11 in

[0111] In this preferred embodiment, the VND14NV04 field effect transistor in the OMNIFET II series of STMicroelectronics is used for power amplification, and its maximum drive current is 12A.

[0112] For the electromagnetic drive in this electronic control device, a high and low side combined drive method is adopted. Among them, M1 is a high side drive MOSFET, and its Gate pole is controlled by HO0. M2 is a low side drive MOSFET, and its Gate pole is controlled by LO0. The IR2181S chip is used to drive the field effect transistor, and its input comes from the same PWM signal to ensure that the high and low side drives are opened or closed simultaneously; Figure 4 The 39th and 40th pins in Figure 5 are respectively connected to the control ends of the shock absorber solenoid valves. The high side drive requires a high voltage signal to open the Gate pole of the high side drive M1. The present invention uses the chip PAM2421 to generate a high level, and a 17V boost signal is generated by configuring two resistors R30 and R31 for opening the high side Gate pole, as

[0113] Figure 6 The schematic diagram of the left front suspension solenoid valve drive current feedback circuit of the electronic control device of the present invention is shown as follows.

[0114] Figure 1The left front suspension (FL) current feedback circuit 6, the right front suspension (FR) current feedback circuit 8, the left rear suspension (RL) current feedback circuit 10, and the right rear suspension (RR) current feedback circuit 12 are used to perform hardware output error correction on the solenoid valve drive current.

[0115] Figure 6 In the design of the current feedback circuit, the voltage differential amplifier AD8200 is adopted, and its pin 40 and pin S0 are connected to Figure 4 both ends of the sampling resistor R34. The output voltage range after the sampling resistor and the differential amplifier is 0.6 - 3.2V, which is read in through the ATD sampling port of the microprocessor. The output current on the solenoid valve and the sampling value of the ATD satisfy a linear relationship. Through this relationship, the microprocessor can obtain the output current of each solenoid valve in real time for hardware output error correction.

[0116] Figure 7 The schematic diagram of the high - frequency signal processing circuit 16 of the electronic control device of the present invention is shown.

[0117] The high - frequency signal processing circuit 16 is used to collect the vehicle body vertical acceleration signal and input the processed signal to the microprocessor 2. The vehicle body vertical acceleration sensors 25 at the left front suspension (FL), 26 at the right front suspension (FR), and 27 at the left rear suspension (RL) of the present invention all adopt the PSI5 interface, and the signal is in the form of Manchester coding.

[0118] In this preferred embodiment, the L9658 of STMicroelectronics is selected as the interface chip for the vehicle body vertical acceleration sensor. The L9658 has 4 independent programmable peripheral sensor interface channels, and this channel is configured with a Manchester decoder, which can directly analyze the acceleration signal and send the decoded acceleration signal to the microprocessor 2 through the SPI method.

[0119] Figure 8 The schematic diagram of the left front suspension height sensor filtering circuit of the present invention is shown.

[0120] The right rear suspension (RL) height sensor signal filtering circuit 17, the right front suspension (FR) height sensor signal filtering circuit 18, and the left front suspension (FL) height sensor signal filtering circuit 19 are used to collect the vehicle body height sensor signal and input the processed signal to the microprocessor 2. Figure 8 The height sensor of the exemplified left front suspension height sensor filtering circuit has a total of 3 wires. Among them, pin 23 is connected to the 5V provided by the power supply module, pin 24 is connected to GND, and pin 8 is the signal wire, which is sent to the microprocessor through the PWM signal method with a fixed frequency and variable duty cycle.

[0121] The voltage dividing circuit 20 is used to collect the signals of the mode switch and input them to the microprocessor.

[0122] The mode switch 21 is used for driver demand input and usually has mode selection functions such as "standard type", "sport type" and "comfort type".

[0123] The body height sensors 22 at the left front suspension (FL), 23 at the right front suspension (FR) and 24 at the left rear suspension (RL) are used to measure the relative height values of the unsprung mass and sprung mass of the vehicle, which characterize the degree of suspension stretching or compression.

[0124] Furthermore, the body height sensor is used to measure the relative height value between the body and the wheel, which characterizes the degree of suspension stretching or compression. A complete height sensor includes two parts: a sensor body and a link bracket. The sensor body is installed on the body, and the link bracket is installed on the wheel. During the operation of the vehicle, the relative position between the body and the wheel changes continuously, driving the link bracket to move and converting it into a change of the height sensor through a ball joint. The number of body height sensors can be four or three. If a four-body height sensor layout scheme is adopted, they are respectively arranged at the four suspensions of the left front, right front, left rear and right rear to monitor the vertical height values at the four suspensions in real time. If a three-body height sensor layout scheme is adopted, they are respectively arranged at the three suspensions of the left front, right front and left rear of the body, and the body height value at the right rear suspension can be estimated from the values of the other three body height sensors.

[0125] This preferred embodiment uses a new generation of intelligent non-contact position sensors produced by Continental of Germany, and the output voltage is a variable duty cycle signal with a constant period, and the duty cycle is linearly related to the suspension height.

[0126] The body vertical acceleration sensors 25 at the left front suspension (FL), 26 at the right front suspension (FR) and 27 at the left rear suspension (RL) are used to measure the vertical acceleration values at the hard points of the body suspension in real time.

[0127] Furthermore, the body vertical acceleration sensor is used to measure the vertical acceleration value at the hard point of the body suspension in real time. The number of body vertical acceleration sensors can be four or three. If a four-body vertical acceleration sensor layout scheme is adopted, they are respectively arranged at the upper hard points of the four suspensions of the left front, right front, left rear and right rear of the body to monitor the vertical acceleration values at the hard points of the body suspension in real time. If a three-body vertical acceleration sensor layout scheme is adopted, they are respectively arranged at the upper hard points of the three suspensions of the left front, right front and left rear of the body, and the vertical acceleration value at the upper hard point of the right rear suspension of the body can be estimated from the values of the other three vertical acceleration sensors.

[0128] In this preferred embodiment, a digital chassis acceleration sensor produced by Continental of Germany is adopted, and the output is a digital signal that meets the PSI5 interface standard.

[0129] The solenoid valves 28 for the left front suspension (FL) shock absorber, the solenoid valve 29 for the right front suspension (FR) shock absorber, the solenoid valve 30 for the left rear suspension (RL) shock absorber, and the solenoid valve 31 for the right rear suspension (RR) shock absorber are electro-controlled pilot-operated proportional throttle valves, with an input control current of 0 - 1.6 A and a response frequency exceeding 1 GHz.

[0130] Figure 9 The following shows the flow chart of the control method of the present invention applying the present invention.

[0131] The present invention proposes a control method for an automotive damping continuously adjustable semi-active suspension. Each step includes initialization S1, signal reading S2, state estimation S3, sub-task control S4, multi-task priority switching control S5, and PWM control output S6. The following specifically introduces each step in sequence:

[0132] Initialization S1 includes sensor signal initialization, CAN signal initialization, and initialization of the damping continuously adjustable shock absorber solenoid valve.

[0133] Among them, sensor signal initialization refers to the body height sensors 22 at the left front suspension (FL), the body height sensors 23 at the right front suspension (FR), the body height sensors 24 at the left rear suspension (RL), the body vertical acceleration sensors 25 at the left front suspension (FL), the body vertical acceleration sensors 26 at the right front suspension (FR), and the body vertical acceleration sensors 27 at the left rear suspension (RL), respectively completing the register initialization configuration of the corresponding ports. The CAN signals refer to vehicle speed signals, steering wheel angle signals, steering wheel angular velocity signals, vehicle longitudinal acceleration signals, and yaw rate signals, and complete the register initialization configuration of the CAN module.

[0134] Signal reading S2 obtains the mode switch, the special sensor signals of the damping continuously adjustable shock absorber system, and the vehicle CAN signals. Among them, the signals of the body height sensors 22 at the left front suspension (FL), the body height sensors 23 at the right front suspension (FR), and the body height sensors 24 at the left rear suspension (RL) are directly read in the form of PWM signals. The signals of the body vertical acceleration sensors 25 at the left front suspension (FL), the body vertical acceleration sensors 26 at the right front suspension (FR), and the body vertical acceleration sensors 27 at the left rear suspension (RL) are read through Manchester decoder and parsed in the form of SPI. The vehicle CAN signals are read in the form of messages and parsed according to the DBC protocol.

[0135] State estimation S3 estimates two types of states, namely the suspension system motion state and the vehicle motion state. The suspension system motion state includes the body vertical motion speed, the relative suspension motion speed, and the wheel vertical motion speed. The body vertical speeds at the left front (FL), right front (FR), and left rear (RL) suspensions are obtained respectively from the signals of the body vertical acceleration sensors installed at the left front (FL), right front (FR), and left rear (RL) suspensions through an integral filtering algorithm. The body vertical speed at the right rear (RR) suspension is estimated from the body vertical speed at the right front (FR) suspension based on vehicle speed and wheelbase information. The relative suspension motion speeds at the left front (FL), right front (FR), and left rear (RL) suspensions are obtained respectively from the signals of the body height sensors installed at the left front (FL), right front (FR), and left rear (RL) suspensions through a differential filtering algorithm. The relative motion speed at the right rear (RR) suspension is estimated from the relative motion speeds at the right front (FR) and left rear (RL) suspensions. The four wheel vertical motion speeds are obtained through geometric operation relationships between the body vertical speeds and the relative motion speeds at the four suspensions. The vehicle motion state includes acceleration, braking, steering, and instability, which are measured in real time by longitudinal acceleration sensors, steering wheel angle sensors, yaw rate sensors, etc. equipped in other vehicle electronic control systems and transmitted through the CAN bus.

[0136] Sub-task control S4 performs sub-task control for different vehicle operating states, including body vertical vibration control, body pitch control, body roll control, wheel vertical vibration control, and vehicle instability control.

[0137] Among them, different control methods are adopted for body vertical vibration control in different system modes. In the comfort mode, aiming to improve comfort, skyhook control with adjustable gain is adopted. In the sport mode, aiming to improve handling and stability, groundhook control with adjustable gain is adopted. In the standard mode, an improved skyhook control strategy with adjustable gain is adopted, taking into account both comfort and handling and stability. For body roll attitude control, a roll state estimation method is first designed based on the Kalman filter, and the desired additional anti-roll moment of the vehicle is output using sliding mode variable structure control, and the active anti-roll control of the vehicle is achieved through the damping force of the damping adjustable shock absorber. The body pitch attitude control is similar to the body roll attitude control. The wheel vertical motion control mainly focuses on controlling the tire grip of the wheels and is only enabled in the sport mode, that is, groundhook control with adjustable gain is adopted. Instability control means that when the vehicle experiences lateral instability, the semi-active suspension should take into account handling and stability. The difference between the actual yaw rate and the ideal reference yaw rate is used as the steering characteristic control deviation, and the additional yaw moment is obtained based on the sliding mode variable structure control method. Then, by analyzing the influence of the load transfer amount on both sides of the vehicle on the vehicle steering characteristics, the lateral stability of the vehicle is improved.

[0138] The multi-task priority switching control S5, based on the sub-task control S4, uses decision parameters such as vehicle speed, longitudinal acceleration, steering wheel angle, and yaw rate to judge the vehicle running state through threshold values, and switches different control tasks in a priority manner to obtain the final decision current.

[0139] The specific switching method is as follows:

[0140]

[0141] The control output S6 converts the decision current obtained by the multi-task priority switching control S5 into the corresponding PWM output through interpolation, collects the actual current value of the corresponding solenoid valve through the current feedback circuit, and uses the current value after error correction to control the solenoid valve of the continuously variable damping shock absorber.

[0142] In summary, the electronic control device and its control method of the present invention can propose an electronic control device for an automotive continuously variable damping semi-active suspension including a power supply circuit, a CAN communication module, a solenoid valve drive circuit, an output current feedback circuit, a BDM debugging circuit, a clock circuit, a reset circuit, a vehicle body vertical acceleration high-frequency signal processing circuit, a vehicle body height sensor signal filtering circuit, and a voltage dividing circuit, based on two types of signals from the vehicle body vertical acceleration sensor and the vehicle body height sensor, as well as a control method including initialization, signal reading, state estimation, sub-task control, multi-task priority switching control, and PWM output, to perform dynamic real-time control on four continuously variable damping shock absorbers, thereby solving the technical problem between vehicle ride comfort and handling stability.

[0143] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

[0144] At the same time, this application uses specific terms to describe the embodiments of this application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0145] Some aspects of the present application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above-mentioned hardware or software can all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor can be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, aspects of the present application may be embodied as a computer product located in one or more computer-readable media, which includes computer-readable program code. For example, the computer-readable media may include, but is not limited to, magnetic storage devices (such as hard disks, floppy disks, magnetic tapes...), optical disks (such as compact disks CD, digital versatile disks DVD...), smart cards, and flash memory devices (such as cards, sticks, key drives...).

[0146] The computer-readable media may contain a propagated data signal that contains computer program code, for example, on a baseband or as part of a carrier wave. The propagated signal may have various forms of representation, including electromagnetic form, optical form, etc., or a suitable combination of forms. The computer-readable media can be any computer-readable media other than computer-readable storage media, which can be connected to an instruction execution system, apparatus, or device to achieve communication, propagation, or transmission for use of the program. The program code located on the computer-readable media can be propagated through any suitable media, including radio, cable, fiber optic cable, radio frequency signal, or similar media, or any combination of the above media.

[0147] Similarly, it should be noted that, in order to simplify the presentation of the disclosure of the present application and thus help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, sometimes multiple features are grouped into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the subject matter of the present application are more than those mentioned in the claims. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.

[0148] In some embodiments, numbers are used to describe components and the quantity of attributes. It should be understood that such numbers used in the description of embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may vary according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used to confirm the breadth of the scope in some embodiments of the present application are approximate values, in specific embodiments, such numerical settings are made as precise as possible within the feasible range.

[0149] Although the present application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications of the above embodiments are within the scope of the spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A control method for an automotive damping continuously adjustable semi-active suspension, characterized in that, it includes: Step 1, initialization; Step 2, obtaining the body vertical height and body vertical acceleration including the mode signal and three suspension positions; Step 3, obtaining the fourth body vertical height and body vertical acceleration based on the three body vertical heights and body vertical accelerations; Step 4, performing sub-task control for different operating states of the whole vehicle such as uniform speed, acceleration, braking, steering and instability, including body vertical vibration control, body pitch control, body roll control, wheel vertical vibration control and vehicle instability control; Among them, for body roll attitude control, first design a roll state estimation method based on the Kalman filter, and use the sliding mode variable structure control to output the desired additional anti-roll moment of the vehicle, and realize the active anti-roll control of the vehicle through the damping force of the damping adjustable shock absorber; The wheel vertical motion control mainly focuses on controlling the wheel grip and is only enabled in the sports mode, that is, using the gain adjustable skyhook control; For vehicle instability control, the difference between the actual yaw angular velocity and the ideal reference angular velocity is used as the steering characteristic control deviation, and the additional yaw moment is obtained based on the sliding mode variable structure control method. Then, by analyzing the influence of the load transfer amount on both sides of the vehicle on the vehicle steering characteristics, the lateral stability of the vehicle is improved; Step 5, according to the decision-making parameters, judge the operating state of the whole vehicle through threshold values, switch the sub-tasks including vertical vibration control, pitch attitude control, roll attitude control and instability control in a priority manner, and obtain the final decision-making current; Among them, the decision-making parameters include vehicle speed v, longitudinal acceleration a x , steering wheel angle δ, and yaw rate γ. The running state of the whole vehicle is judged through thresholds, and different control tasks are switched in a priority manner to obtain the final decision-making current. The specific switching method is as follows: If v > v th and |a x | < a xth and |δ| < δ th , it is determined that the vehicle state is in uniform linear motion, and the control task is switched to vertical vibration control in priority mode IV; If v > v th and |a x | ≥ a xth and |δ| < δ th , determine that the vehicle state is accelerating or braking, and switch to the control task of pitch attitude control in priority mode III; If v > v th and |a x | < a xth and |δ| ≥ δ th , it is determined that the vehicle state is steering or curve driving, and the priority mode II is used to switch to the control task of roll attitude control; If v > v th and |γ| > γ th , it is determined that the vehicle state is in lateral instability, and the control task is switched to instability control in priority mode I; Step 6, convert the decision-making current into the corresponding PWM output, collect the actual current value of the corresponding solenoid valve through the current feedback circuit, and use the error-corrected current value to control the solenoid valve of the damping continuously adjustable shock absorber.

2. The control method for an automotive damping continuously adjustable semi-active suspension according to claim 1, characterized in that, the three suspension positions in step 2 include the left front, right front and left rear suspension positions; In step 3, the fourth suspension position includes the right rear suspension, and its body vertical speed is obtained according to the body vertical speed at the right front suspension based on the vehicle speed and wheelbase information, and its relative motion speed is obtained according to the relative motion speeds at the right front and left rear suspensions.

3. The control method for an automotive damping continuously adjustable semi-active suspension according to claim 2, characterized in that, in step 4, it further includes: The modes include standard, sports and comfort. The comfort mode uses the gain adjustable skyhook control, the sports mode uses the gain adjustable groundhook control, and the standard mode uses the gain adjustable improved skyhook control.

4. An electronic control device for an automotive damping continuously adjustable semi-active suspension, applicable to the control method for an automotive damping continuously adjustable semi-active suspension according to any one of claims 1 to 3, and the electronic control device for an automotive damping continuously adjustable semi-active suspension is used to control the solenoid valve of the shock absorber arranged at the body suspension position, characterized in that, it includes: An acquisition unit for acquiring the body vertical height signal and body vertical acceleration signal including the suspension position; A control unit that provides a control signal for the shock absorber solenoid valve according to the body vertical height signal and the body vertical acceleration signal of the suspension position; A solenoid valve drive circuit, through which the control unit controls the shock absorber solenoid valve; A plurality of current feedback circuits, connected to the control unit through an A / D conversion unit, to feedback the current of the shock absorber solenoid valve to the control unit for error correction of the drive current of the shock absorber solenoid valve drive circuit.

5. The electronic control device for an automotive damped continuously adjustable semi-active suspension according to claim 4, characterized in that the acquisition unit acquires the body vertical height signal of the suspension position through its PWM peripheral interface.

6. The electronic control device for an automotive damped continuously adjustable semi-active suspension according to claim 5, characterized in that the body vertical height signal and the body vertical acceleration signal are respectively provided by three groups of body sensors located at three suspension positions, and the control unit obtains the body vertical height signal and the body vertical acceleration signal of the fourth suspension position accordingly.

7. The electronic control device for an automotive damped continuously adjustable semi-active suspension according to claim 6, characterized in that it includes: the control unit controls the solenoid valve drive circuit through a PWM output port.

8. The electronic control device for an automotive damped continuously adjustable semi-active suspension according to claim 7, characterized in that the control unit includes a PSI5 peripheral sensing interface, through which the control unit reads the signal sent by the body vertical acceleration sensor.

9. The electronic control device for an automotive damped continuously adjustable semi-active suspension according to claim 8, characterized in that the control unit further receives a mode selection and controls accordingly, and the mode selection includes one of standard type, sport type and comfort type.

10. The electronic control device for an automotive damped continuously adjustable semi-active suspension according to claim 4, characterized in that the solenoid valve drive circuit adopts a high and low side combined drive method, and simultaneously controls two MOSFET circuits on the high side and the low side through a MOSFET drive chip to ensure the response of the shock absorber solenoid valve.

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