Analog signal output device for air spring controller

Abstract

The embodiment of the utility model provides analog signal output equipment for an air spring controller. The analog signal output equipment comprises a main control chip, a PWM amplitude conversion unit, a PWM-to-analog unit, a state selection unit and an IO signal conversion unit, wherein the IO signal conversion unit converts an IO signal into a preset output voltage signal; the PWM amplitude conversion unit performs amplitude conversion on the multiple paths of PWM signals output by the main control chip to correspondingly generate multiple paths of converted PWM signals; the PWM-to-analog unit is used for correspondingly converting a part of the converted PWM signals into multiple paths of analog signals; the state selection unit controls output signals corresponding to the multipath conversion PWM signals and the multipath analog signals, so that the normal working state of a sensor of the air spring controller is simulated through the output signals corresponding to the multipath conversion PWM signals and the multipath analog signals and the preset output voltage signals. According to the invention, the normal working state and fault state of the input sensor of the air spring controller can be simulated.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to the field of automobile air-conditioning temperature and pressure sensor parts technology. Background Art

[0002] When the air spring controller is working, it is connected to multiple sensors of different types and numbers to receive and process the rotation angle, acceleration, temperature, pressure signals collected by the sensors, so as to make corresponding decisions. Therefore, judging the performance of the sensor and how to deal with sudden sensor failures are extremely important for vehicle intelligent driving. When testing the software functions of the air spring controller, fault testing is required to deal with sudden situations such as sensor abnormalities. At present, the sensor input tests used for air spring controllers are built with different types of real sensors and can only be adjusted manually or using a more expensive HIL bench. If performed manually, there are problems of low test efficiency and inconvenience. If a HIL bench is used, although the efficiency is improved, the price is expensive. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide an analog signal output device for an air spring controller, which is used to simulate the signal of an input sensor of the air spring controller.

[0004] The present application provides an analog signal output device for an air spring controller, comprising: a main control chip, a PWM amplitude conversion unit, a PWM to analog unit, a state selection unit and an IO signal conversion unit; wherein: the serial port interface of the main control chip receives external control instructions, generates multiple PWM signals, outputs IO signals to the IO signal conversion unit, and generates state instructions for controlling the state selection unit based on the external control instructions; the IO signal conversion unit converts the IO signal into a preset output voltage signal; the PWM amplitude conversion unit is connected to the main control chip, performs amplitude conversion on the multiple PWM signals output by the main control chip, and generates corresponding state instructions for controlling the state selection unit. into a multiplexed PWM signal; the PWM-to-analog unit is connected to the PWM amplitude conversion unit, and converts a portion of the converted PWM signals output by the PWM amplitude conversion unit into corresponding multiplexed analog signals; the state selection unit is respectively connected to the PWM amplitude conversion unit and the PWM-to-analog unit, and controls the multiplexed PWM signals and the output signals corresponding to the multiplexed analog signals respectively based on the state instructions output by the main control chip, so as to simulate the normal working state of the sensor of the air spring controller through the multiplexed PWM signals and the output signals corresponding to the multiplexed analog signals and the preset output voltage signal output by the IO signal conversion unit.

[0005] In one implementation of the present application, the main control chip generates multiple PWM signals using a timer.

[0006] In one embodiment of the present application, the IO signal conversion unit includes a first transistor and a second transistor; wherein, the base of the first transistor receives the IO signal output by the main control chip, the emitter is grounded, the collector is connected to the base of the second transistor, the emitter of the second transistor is connected to a preset voltage, and the collector outputs a preset output voltage signal.

[0007] In one embodiment of the present application, the voltage of the IO signal is 3.3V, and the preset voltage is 12V.

[0008] In one embodiment of the present application, the PWM-to-analog unit includes a plurality of groups of PWM-to-analog modules, and each group of the PWM-to-analog modules converts one of the converted PWM conversion signals into one of the analog signals.

[0009] In one embodiment of the present application, each group of the PWM-to-analog modules includes an RC filter circuit to convert the converted PWM conversion signal into the analog signal.

[0010] In one embodiment of the present application, the state selection unit includes a plurality of switch selection units, and each switch selection unit corresponds to one conversion PWM signal or one analog signal.

[0011] In one embodiment of the present application, each group of the switch selection units includes: a single-pole four-throw switch; the four static contacts of the single-pole four-throw switch correspond to the short-circuit to ground state, open circuit state, short-circuit to power state and normal state of the output signal respectively.

[0012] In one embodiment of the present application, the duty cycle of the converted PWM signal generated by the PWM amplitude conversion unit varies in a range of 0 to 100%; and the frequency varies in a range of 500 Hz to 2 khz.

[0013] In one implementation of the present application, the serial port interface of the main control chip is communicatively connected to a host computer, and receives the external control instruction from the host computer.

[0014] As described above, the analog signal output device for the air spring controller provided in the embodiment of the present application can simulate the normal working state and fault state of the input sensor of the air spring controller to facilitate the testing of the air spring controller and the simulation of real vehicle phenomena. When testing the air spring controller, the present application can use the host computer control device to simulate the sensor signal to achieve the purpose of automatically testing whether the hardware and software of the air spring controller are normal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A schematic diagram showing the structural principle of an analog signal output device for an air spring controller in one embodiment of the present application is shown.

[0016] Figure 2 A schematic diagram showing the principle structure of an IO signal conversion unit in an analog signal output device for an air spring controller in one embodiment of the present application is shown.

[0017] Figure 3 A schematic diagram showing the principle structure of a group of PWM to analog modules in an analog signal output device for an air spring controller in one embodiment of the present application is shown.

[0018] Figure 4 A schematic diagram showing the principle structure of a group of switch selection units in an analog signal output device for an air spring controller in one embodiment of the present application is shown.

[0019] Component number description

[0020] 100 Analog signal output device for air spring controller 100

[0021] 110 Main control chip

[0022] 120 IO signal conversion unit

[0023] 130 PWM amplitude conversion unit

[0024] 140 PWM to analog unit

[0025] 150 state selection unit DETAILED DESCRIPTION

[0026] The following is an explanation of the embodiments of the present application by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the information disclosed in the present application. The present application can also be implemented or applied through other different specific embodiments, and the details in the present application can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0027] Below Figure 1 and Figure 4 For reference, the embodiments of the present application are described in detail so that those skilled in the art can easily implement the present application. The present application can be embodied in many different forms and is not limited to the embodiments described herein.

[0028] In the representations of the present application, the representations with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the represented specific features, structures, materials or characteristics may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples represented in the present application and the features of the different embodiments or examples, without contradiction.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of this application, "a group" means two or more, unless otherwise clearly and specifically defined.

[0030] In order to clearly describe the present application, components irrelevant to the description are omitted, and the same reference symbols are given to the same or similar components throughout the specification.

[0031] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0032] Although the terms first, second, etc. are used to represent various elements in this article in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising", "including" indicate that there are described features, steps, operations, elements, modules, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or a group of other features, steps, operations, elements, modules, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, the exception of this definition will occur.

[0033] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present application. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0034] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which this application belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and as long as they are not defined, they should not be overly interpreted as ideal or very formal meanings.

[0035] The purpose of the embodiment of the present application is to provide an analog signal output device for an air spring controller, which is used to simulate the signal of an input sensor of the air spring controller.

[0036] The analog signal output device for the air spring controller of this embodiment is described in detail below, so that those skilled in the art can understand the analog signal output device for the air spring controller of this embodiment without creative work.

[0037] This embodiment provides an analog signal output device for an air spring controller. Figure 1 The following is a schematic diagram showing the structure and principle of an analog signal output device for an air spring controller in one embodiment of the present application. Figure 1 As shown, the analog signal output device for the air spring controller in this embodiment includes: a main control chip 110, a PWM amplitude conversion unit 130, a PWM to analog unit 140, a state selection unit 150 and an IO signal conversion unit 120.

[0038] In the present application, the state selection unit 150 can control the output channel to display different states externally, so that the simulated sensor can simulate the normal working state and fault state of the real sensor. The main control chip 110, the PWM amplitude conversion unit 130, the PWM to simulation unit 140, the state selection unit 150 and the IO signal conversion unit 120 in the present application are specifically described below.

[0039] In this embodiment, the serial port interface of the main control chip 110 receives external control instructions, generates multiple PWM signals, outputs IO signals to the IO signal conversion unit 120, and generates state instructions for controlling the state selection unit 150 based on the external control instructions.

[0040] In a specific implementation of this embodiment, the serial port interface of the main control chip 110 is connected to the host computer for communication, and receives the external control instruction from the host computer.

[0041] That is, in this embodiment, the serial port interface of the main control chip 110 can be used to receive control instructions from the host computer, and the host computer control device can be used to simulate the sensor signal to achieve the purpose of automatically testing whether the hardware and software of the air spring controller are normal.

[0042] In a specific implementation of this embodiment, the main control chip 110 generates multiple PWM signals using a timer.

[0043] In this embodiment, the timer can generate multiple PWM signals in a variety of ways. Exemplarily, the output comparison mode of the STM32 timer is used. In addition to the basic PWM output mode, the STM32 timer also has an output comparison mode. This mode can generate multiple PWMs with different frequencies and duty cycles. Specifically, first, the basic parameters of the timer are configured, including a prescaler (TIMx_PSC) and an automatic reload register (TIMx_ARR). These parameters determine the base frequency of the PWM waveform. Then, the duty cycle of each channel is changed by setting the comparison capture register (CCRx) of each channel, thereby generating the required multi-channel PWM signals.

[0044] In some other embodiments, multiple timers may be used to generate multiple PWM signals. For example, each timer is initialized first, and its pre-scaling coefficient (psc) and auto-reload register (arr) are set to determine the frequency of PWM. Then, the duty cycle of each channel is set through a function such as TIM_SetComparex to generate the required multiple PWM signals.

[0045] In this embodiment, the IO signal conversion unit 120 converts the IO signal into a preset output voltage signal.

[0046] Figure 2 The schematic diagram of the principle structure of the IO signal conversion unit 120 in the analog signal output device 100 for the air spring controller in one embodiment of the present application is shown. Figure 2 As shown, in a specific implementation of this embodiment, the IO signal conversion unit 120 includes a first transistor Q1 and a second transistor Q2; wherein the base of the first transistor Q1 receives the IO signal output by the main control chip 110, the emitter is grounded, the collector is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is connected to a preset voltage, and the collector outputs a preset output voltage signal.

[0047] Specifically, in this embodiment, the base of the first transistor Q1 is connected to a 3.3V control signal through an appropriate current-limiting resistor R1, wherein the current-limiting resistor is required to ensure that sufficient base current can be provided at 3.3V to turn on the first transistor Q1. The emitter of the first transistor Q1 is grounded, and the collector is connected to the base of the second transistor Q2 through a resistor R2, and is connected to a 12V power supply through a resistor R3 after passing through the resistor R2. The emitter of the second transistor Q2 is connected to a 12V power supply, and the collector outputs a 12V voltage, wherein a light-emitting diode LED1 can be connected to the collector of the second transistor Q2, and when the second transistor Q2 is turned on by the 12V power supply, an indication is given by the light-emitting diode LED1.

[0048] In this embodiment, illustratively, the voltage of the IO signal is 3.3V, and the preset voltage is 12V, that is, the preset output voltage signal is 12V. The 3.3V IO signal is converted into a 12V signal by the IO signal conversion unit 120 of this embodiment, that is, 3.3V is used to control the conduction of 12V for use by the 12V channel. This application provides a 3.3V to 12V channel so that the analog signal output device can send a 12V voltage signal to the outside (empty spring controller).

[0049] In a specific implementation of this embodiment, the voltage of the IO signal is 3.3V, and the preset voltage is 12V.

[0050] In this embodiment, the PWM amplitude conversion unit 130 is connected to the main control chip 110 , performs amplitude conversion on multiple PWM signals output by the main control chip 110 , and generates multiple converted PWM signals accordingly.

[0051] For example, in this embodiment, the PWM amplitude conversion unit 130 converts a PWM wave with a peak value of 3.3V into a PWM wave with a peak value of 5V. To convert a PWM wave with a peak value of 3.3V into a PWM wave with a peak value of 5V, an NPN transistor, a NOT gate circuit, a level conversion circuit, a MOS tube, etc. can be used.

[0052] For example, through the switching characteristics of the NPN transistor, the 3.3V PWM signal is converted to 5V. Specifically, a current limiting resistor is added between the PWM signal and the transistor, and an appropriate power supply voltage (here 5V) is connected. When the PWM signal is high, the transistor is saturated and turned on, and the output voltage is close to 5V; when the PWM signal is low, the transistor is cut off and the output voltage is 0V.

[0053] For another example, a NOT gate circuit is used to convert a 3.3V PWM signal to 5V. Specifically, a 74HC04 NOT gate chip is used for level conversion. The power supply terminal of the 74HC04 chip is connected to a 5V voltage, and a 3.3V PWM signal is added to the input terminal. Due to the characteristics of the NOT gate, a 5V PWM wave will be obtained at the output terminal, but the duty cycle will be reversed.

[0054] In a specific implementation of this embodiment, in order to simulate the normal working state of the real sensor by the simulated sensor, the duty cycle and frequency of the 3.3v PWM wave of the PWM amplitude conversion unit provided by the main control chip 110 can be changed. The duty cycle of the converted PWM signal generated by the PWM amplitude conversion unit 130 varies from 0 to 100%; the frequency varies from 500hz to 2khz.

[0055] In this embodiment, the PWM-to-analog unit 140 is connected to the PWM amplitude conversion unit 130 , and converts a portion of the converted PWM signal output by the PWM amplitude conversion unit 130 into multiple analog signals.

[0056] In a specific implementation of this embodiment, the PWM to analog unit 140 includes multiple groups of PWM to analog modules, each group of the PWM to analog modules converts one channel of the converted PWM conversion signal into one channel of analog signal. That is, the PWM to analog unit 140 includes multiple groups of PWM to analog modules, each group of PWM to analog modules corresponds to one channel.

[0057] Exemplarily, each group of the PWM to analog modules converts a PWM wave with a peak value of 5v into a stable voltage value. The converted stable voltage is related to the peak value and duty cycle of the PWM wave, and the specific calculation formula is V=Umax*Duty(v). For example: a PWM wave with an amplitude of 5v and a duty cycle of 50% will be converted into a stable voltage of 2.5v after being converted by the PWM to analog module, 5v*50%=2.5v.

[0058] Among them, converting the PWM wave with a peak value of 5V into a stable voltage value can be achieved by using methods such as RC low-pass filter, Bessel filter, Butterworth filter and single-stage or multi-stage filtering.

[0059] Figure 3 The schematic diagram of the principle structure of a group of PWM to analog modules in the analog signal output device 100 for the air spring controller in one embodiment of the present application is shown. Figure 3As shown, in a specific implementation of this embodiment, each group of the PWM to analog modules includes an RC filter circuit (composed of a resistor R1 and a capacitor C1, a resistor R2 and a capacitor C2), which converts the converted PWM conversion signal into the analog signal accordingly.

[0060] In this embodiment, the state selection unit 150 is connected to the PWM amplitude conversion unit 130 and the PWM to analog unit 140, respectively, and controls the output signals corresponding to the multiplexed PWM signals and the multiplexed analog signals based on the state instructions output by the main control chip 110, so as to simulate the normal working state of the sensor of the air spring controller through the output signals corresponding to the multiplexed PWM signals and the multiplexed analog signals and the preset output voltage signal output by the IO signal conversion unit 120.

[0061] Specifically, in a specific implementation of this embodiment, the state selection unit 150 includes a plurality of switch selection units, and each switch selection unit corresponds to one conversion PWM signal or one analog signal.

[0062] Figure 4 The schematic diagram of the principle structure of a group of switch selection units in the analog signal output device 100 for the air spring controller in one embodiment of the present application is shown. Figure 4 As shown, in a specific implementation of this embodiment, each group of the switch selection units includes: a single-pole four-throw switch; the moving contact 0 of the single-pole four-throw switch can be respectively connected to the four stationary contacts ( Figure 4 1, 2, 3, 4) shown in the figure, the four static contacts of the single-pole four-throw switch correspond to the short-circuit to ground state, open circuit state, short-circuit to power state and normal state of the output signal respectively. Each group of switch selection units is equivalent to a single-pole four-throw switch, and selects a working state according to state instruction category 1 (state_in0) and state instruction category 2 (state_in1), so that the corresponding output channel also shows different states to the outside, so that the simulated sensor can realize the simulation of the normal working state and fault state of the real sensor. Table 1 shows the correspondence between the state of the switch selection unit and the state instruction category.

[0063] Table 1

[0064] Status command category Selected state state_in0=0; state_in1=0; Normal state_in0=1; state_in1=0; Openload (open circuit state) state_in0=0; state_in1=1; ShortGnd (short circuit to ground state) state_in0=1; state_in1=1; ShortPower (short circuit to power state)

[0065] For example, in this embodiment, the connection status of channels 1 to 4 is that the state selection unit 150 is connected to the PWM amplitude conversion unit 130; the connection status of channels 5 to 10 is that the state selection unit 150 is connected to the PWM to analog unit 140, and the PWM to analog unit 140 is further connected to the PWM amplitude conversion unit 130.

[0066] In this embodiment, in order to realize the simulation of abnormal working state of the real sensor by the simulated sensor,

[0067] like Figure 4 As shown, when the main control chip 110 receives a control instruction sent from the outside, it controls the level of the state instruction pin of the state selection unit 150. The level of the pin is set according to the received control instruction, thereby selecting the state of a channel.

[0068] For example, if the control instruction is that channels 1-4 are in a short-circuit state to ground, channels 5-7 are in an open-circuit state, and channels 8-10 are in a short-circuit state to power, then the corresponding state instruction of the state selection unit 150 is:

[0069] The state instruction category 1 of channel 1 is Ch1_state_in0=0; the state instruction category 2 of channel 1 is Ch1_state_in1=1; the state instruction category 1 of channel 2 is Ch2_state_in0=0; the state instruction category 2 of channel 2 is Ch2_state_in1=1; the state instruction category 1 of channel 3 is Ch3_state_in0=0; the state instruction category 2 of channel 3 is Ch3_state_in1=1; the state instruction category 1 of channel 4 is Ch4_state_in0=0; the state instruction category 2 of channel 4 is Ch4_state_in1=1; the state instruction category 1 of channel 5 is Ch5_state_in0=1; the state instruction category 2 of channel 5 is Ch5_state_in1=0; The state instruction category 1 of channel 6 is Ch6_state_in0=1; the state instruction category 2 of channel 6 is Ch6_state_in1=0; the state instruction category 1 of channel 7 is Ch7_state_in0=1; the state instruction category 2 of channel 7 is Ch7_state_in1=0; the state instruction category 1 of channel 8 is Ch8_state_in0=1; the state instruction category 2 of channel 8 is Ch8_state_in1=1; the state instruction category 1 of channel 9 is Ch9_state_in0=1; the state instruction category 2 of channel 9 is Ch9_state_in1=1; the state instruction category 1 of channel 10 is Ch10_state_in0=1; the state instruction category 2 of channel 10 is Ch10_state_in1=1.

[0070] The corresponding analog sensors are also in corresponding working states.

[0071] In order to simulate the normal working state of the real sensor by the simulated sensor, the duty cycle and frequency of the 3.3v PWM wave of the PWM amplitude conversion unit provided by the main control chip 110 can be changed. The duty cycle ranges from 0 to 100%; the frequency ranges from 500hz to 2khz.

[0072] In the normal state, the state selection unit 150 is also connected to the PWM amplitude conversion unit 130 or the PWM to analog unit 140. For example, the designed outputs of channels 1 to 4 have a duty cycle of 44%, 45%, 46%, and 48% of an amplitude of 5V. The output voltages of channels 5 to 10 are 1.6v, 2.1v, 3.2v, 2.5v, 4.3v, and 0.5v; the duty cycles of the 3.3v PWM wave from the main control chip 110 to the PWM amplitude conversion unit are 44%, 45%, 46%, 48%, 32%, 42%, 64%, 50%, 86%, and 10% respectively.

[0073] In this embodiment, except for the 3.3V to 12V channel, each PWM output channel includes a PWM amplitude conversion unit 130 and a switch selection unit, and each analog signal output channel includes a PWM amplitude conversion unit 130, a PWM to analog module and a switch selection unit.

[0074] In this embodiment, when the analog signal output device 100 for the air spring controller is working, different channels of the analog signal output device send different signals to the outside (air spring controller), including multiple PWM signals, multiple analog (Analog) signals and 12v signals.

[0075] In summary, the analog signal output device for the air spring controller provided in the embodiment of the application can simulate the normal working state and fault state of the input sensor of the air spring controller to facilitate the testing of the air spring controller and the simulation of real vehicle phenomena. When testing the air spring controller, the application can use the host computer control device to simulate the sensor signal to achieve the purpose of automatically testing whether the hardware and software of the air spring controller are normal.

[0076] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. An analog signal output device for an air spring controller, characterized in that: include: Main control chip, PWM amplitude conversion unit, PWM to analog unit, state selection unit and IO signal conversion unit; wherein: The serial port interface of the main control chip receives external control instructions, generates multiple PWM signals, outputs IO signals to the IO signal conversion unit, and generates a state instruction to control the state selection unit based on the external control instructions; The IO signal conversion unit converts the IO signal into a preset output voltage signal; The PWM amplitude conversion unit is connected to the main control chip, and performs amplitude conversion on the multiple PWM signals output by the main control chip to generate multiple converted PWM signals accordingly; The PWM to analog unit is connected to the PWM amplitude conversion unit, and converts a part of the converted PWM signal output by the PWM amplitude conversion unit into a multi-channel analog signal; The state selection unit is respectively connected to the PWM amplitude conversion unit and the PWM to analog unit, and controls the output signals corresponding to the multiplexed PWM signals and the multiplexed analog signals based on the state instructions output by the main control chip, so as to simulate the normal working state and fault state of the sensor of the air spring controller through the output signals corresponding to the multiplexed PWM signals and the multiplexed analog signals and the preset output voltage signal output by the IO signal conversion unit.

2. The analog signal output device for an air spring controller according to claim 1, characterized in that: The main control chip generates multiple PWM signals using a timer.

3. The analog signal output device for an air spring controller according to claim 1, characterized in that: The IO signal conversion unit includes a first transistor and a second transistor; wherein the base of the first transistor receives the IO signal output by the main control chip, the emitter is grounded, the collector is connected to the base of the second transistor, the emitter of the second transistor is connected to a preset voltage, and the collector outputs a preset output voltage signal.

4. The analog signal output device for an air spring controller according to claim 3, characterized in that: The voltage of the IO signal is 3.3V, and the preset voltage is 12V.

5. The analog signal output device for an air spring controller according to claim 1, characterized in that: The PWM to analog unit includes a plurality of groups of PWM to analog modules, and each group of the PWM to analog modules converts one channel of the converted PWM conversion signal into one channel of analog signal.

6. The analog signal output device for an air spring controller according to claim 5, characterized in that: Each group of the PWM-to-analog modules includes an RC filter circuit to convert the converted PWM conversion signal into the analog signal accordingly.

7. The analog signal output device for an air spring controller according to claim 1, characterized in that: The state selection unit includes a plurality of switch selection units, each of which corresponds to a conversion PWM signal or an analog signal.

8. The analog signal output device for an air spring controller according to claim 7, characterized in that: Each group of the switch selection units includes: a single-pole four-throw switch; the four static contacts of the single-pole four-throw switch correspond to the short-circuit to ground state, open circuit state, short-circuit to power state and normal state of the output signal respectively.

9. The analog signal output device for an air spring controller according to claim 1, characterized in that: The duty cycle of the converted PWM signal generated by the PWM amplitude conversion unit varies in the range of 0 to 100%; the frequency varies in the range of 500 Hz to 2 kHz.

10. The analog signal output device for an air spring controller according to claim 1, characterized in that: The serial port interface of the main control chip is connected to the host computer for communication, and receives the external control instruction from the host computer.

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