Proximity sensor signal acquisition system and method

Abstract

The invention provides a proximity sensor signal acquisition system and method. The proximity sensor signal acquisition system comprises a main controller, a first signal acquisition circuit and a second signal acquisition circuit, the first signal acquisition circuit comprises a first signal generator, a first processing circuit and a first analog-to-digital converter; the second signal acquisition circuit comprises a second signal generator, a second processing circuit, a second analog-to-digital converter, a decoder and a relay; the number of the first signal generators, the first processing circuits and the relays is equal to that of the proximity sensors; the number of the second signal generators and the second processing circuits is smaller than that of the proximity sensors. According to the invention, proximity sensor signal acquisition is carried out through the first signal acquisition circuit, and fault isolation can be automatically carried out and the second signal acquisition circuit is started to take over proximity sensor signal acquisition when a fault occurs in a certain path. A redundancy acquisition circuit is designed by adopting a smaller proportion number, so that the cost is low, the circuit structure is simple, the occupied space is small and the reliability is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal acquisition, and in particular relates to a proximity sensor signal acquisition system and method. Background Art

[0002] Proximity sensors are non-contact sensors. Because they are non-contact and reduce mechanical damage and extend their service life, they are widely used in position detection and indication of landing gear retraction and extension systems of large aircraft. The inductance value of the proximity sensor of the landing gear retraction and extension system needs to be obtained through the acquisition circuit. Because the proximity sensor signal is very important for the retraction and extension of the landing gear system, it is generally required that the landing gear level proximity sensor and its acquisition circuit have the same life as the aircraft. Compared with the characteristics of inductive proximity sensors, such as simple internal structure, no wearing parts, and long service life, the probability of failure of the proximity sensor acquisition circuit is higher. Therefore, in the process of designing the proximity sensor and the inductance value acquisition and processing circuit, the possibility of failure of the proximity sensor and the acquisition and processing circuit needs to be considered.

[0003] Considering that the proximity sensor and the acquisition circuit work for a long time, the components age and the parameters of the components in the circuit assembly drift, and the distance is displayed when it should be close, and the proximity is displayed when it should be far away. In addition, the proximity sensor is usually installed outside the body and is susceptible to lightning strikes, which may easily cause signal overvoltage and overcurrent in the internal processing circuit, causing irreversible damage to the circuit and other factors leading to circuit failure. Therefore, it is also necessary to design the proximity sensor and the inductance value acquisition and processing circuit with redundancy.

[0004] The traditional method is to use dual sensors and dual redundant circuits at the same location (i.e., the number of proximity sensors and acquisition and processing circuits is 1:1) or to use a single sensor and dual redundant circuits at the same location (i.e., the number of proximity sensors and acquisition and processing circuits is 1:2). This greatly increases the equipment cost, occupies a large space and has a relatively complex structure. Summary of the invention

[0005] The purpose of the present invention is to provide a proximity sensor signal acquisition system and method in view of the deficiencies in the prior art, which has a simple structure and low equipment cost.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A proximity sensor signal acquisition system, comprising:

[0008] A main controller, a first signal acquisition circuit, and a second signal acquisition circuit;

[0009] The first signal acquisition circuit includes a first signal generator, a first processing circuit, and a first analog-to-digital converter. The first processing circuit includes a first amplifier and a first low-pass filter. The first end of the first signal generator is connected to the main controller, and the second end of the first signal generator is connected to the proximity sensor. The first end of the first amplifier is connected to the proximity sensor, the second end of the first amplifier is connected to the first end of the first low-pass filter, the second end of the first low-pass filter is connected to the first end of the first analog-to-digital converter, and the second end of the first analog-to-digital converter is connected to the main controller.

[0010] The second signal acquisition circuit includes a second signal generator, a second processing circuit, a second analog-to-digital converter, a decoder, and a relay. The second processing circuit includes a second amplifier and a second low-pass filter. The first end of the second signal generator is connected to the main controller, the second end of the second signal generator is connected to the first end of the relay, the second end of the relay is connected to the proximity sensor, the first end of the decoder is connected to the main controller, and the second end of the decoder is connected to the third end of the relay. The first end of the second amplifier is connected to the proximity sensor, the second end of the second amplifier is connected to the first end of the second low-pass filter, the second end of the second low-pass filter is connected to the first end of the second analog-to-digital converter, and the second end of the second analog-to-digital converter is connected to the main controller.

[0011] The number of the first signal generators, the number of the first processing circuits, and the number of the relays are equal to the number of the proximity sensors; the number of the second signal generators and the number of the second processing circuits are less than the number of the proximity sensors;

[0012] The second end of the second signal generator is connected in parallel to a plurality of the relays; and the first end of the second amplifier is connected in parallel to a plurality of proximity sensors.

[0013] The present invention collects and processes the signal of the proximity sensor through the first signal acquisition circuit, and can also synchronously take over the signal acquisition and processing of the proximity sensor through the second signal acquisition circuit when a certain circuit fails; compared with the dual-redundancy circuit, the present invention adopts a smaller proportional number for redundant acquisition circuit design, which can ensure that the proximity sensor signal is normally obtained when the acquisition circuit fails, and has the advantages of reduced cost, simple circuit structure, small space occupation and high reliability.

[0014] Furthermore, the quantitative relationship between the second signal generator and the proximity sensor is as follows:

[0015]

[0016] Wherein, s is the number of the second signal generators, n is the number of the proximity sensors, and [] indicates taking the integer part of the number in the brackets.

[0017] Furthermore, the quantitative relationship between the second processing circuit and the proximity sensor is shown in the following formula:

[0018]

[0019] Wherein, t is the number of the second processing circuits, n is the number of the proximity sensors, and [] indicates taking the integer part of the number in the brackets.

[0020] Based on the same inventive concept, the present invention also provides a proximity sensor signal acquisition method, comprising the following process:

[0021] Connecting the first signal generator, the first processing circuit, and the first analog-to-digital converter of the n proximity sensors, disconnecting the decoder, disconnecting the second signal generator, the second processing circuit, the second analog-to-digital converter, and the relay of the n proximity sensors, and collecting the signals of the n proximity sensors;

[0022] When the main controller cannot receive the signal from the i-th proximity sensor, the first signal generator, the first processing circuit, and the first analog-to-digital converter of the i-th proximity sensor are disconnected, the decoder is turned on, and the second signal generator, the second processing circuit, the second analog-to-digital converter, and the relay of the i-th proximity sensor are connected, i=1, 2, ..., n.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention collects and processes the signal of the proximity sensor through the first signal collection circuit, and can also automatically isolate the fault when a certain circuit fails and enable the second signal collection circuit to take over the proximity sensor signal collection; compared with the dual redundancy circuit, the present invention adopts a smaller proportional number for redundant collection circuit design, which can ensure that the proximity sensor signal is normally obtained when the collection circuit fails, and has the advantages of reduced cost, simple circuit structure, small space occupation and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a first signal acquisition circuit of a proximity sensor of the present invention;

[0026] Figure 2 A schematic diagram of a first and a second signal acquisition circuit of a proximity sensor of the present invention;

[0027] Figure 3 is a schematic diagram of a first signal acquisition circuit of eight proximity sensors of the present invention;

[0028] Figure 4is a schematic diagram of the first and second signal acquisition circuits of eight proximity sensors of the present invention;

[0029] Figure 5 The figure is a flow chart of the proximity sensor signal acquisition method of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below in conjunction with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0031] Example

[0032] This embodiment provides a proximity sensor signal acquisition system, which aims to solve the problem that the proximity sensor and the acquisition circuit work for a long time, resulting in aging of components, drift of component parameters in the circuit assembly, and displaying far away when it should be close, and close when it should be far away. In addition, the proximity sensor is usually installed outside the body, which is susceptible to lightning strikes and other effects, which may easily cause the internal processing circuit to have signal overvoltage and overcurrent, causing irreversible damage to the circuit, and other factors that may cause the proximity sensor signal acquisition circuit to fail. A proximity sensor acquisition system with simple circuit structure, small footprint, low cost and high reliability is proposed, which can ensure that the fault path proximity sensor signal is normally obtained without using a dual-redundancy circuit.

[0033] like Figure 1-4 The proximity sensor signal acquisition system of this embodiment includes: a main controller, a first signal acquisition circuit, and a second signal acquisition circuit.

[0034] The first signal acquisition circuit includes a first signal generator, a first processing circuit, and a first analog-to-digital converter (ADC chip). The first processing circuit includes a first amplifier and a first low-pass filter. The first end of the first signal generator is connected to the main controller, and the second end of the first signal generator is connected to the proximity sensor. The first end of the first amplifier is connected to the proximity sensor, the second end of the first amplifier is connected to the first end of the first low-pass filter, the second end of the first low-pass filter is connected to the first end of the first analog-to-digital converter, and the second end of the first analog-to-digital converter is connected to the main controller.

[0035] The second signal acquisition circuit includes a second signal generator, a second processing circuit, a second analog-to-digital converter (ADC chip), a decoder, and a relay. The second processing circuit includes a second amplifier and a second low-pass filter. The first end of the second signal generator is connected to the main controller, the second end of the second signal generator is connected to the first end of the relay, the second end of the relay is connected to the proximity sensor, the first end of the decoder is connected to the main controller, and the second end of the decoder is connected to the third end of the relay. The first end of the second amplifier is connected to the proximity sensor, the second end of the second amplifier is connected to the first end of the second low-pass filter, the second end of the second low-pass filter is connected to the first end of the second analog-to-digital converter, and the second end of the second analog-to-digital converter is connected to the main controller.

[0036] The number of the first signal generators, the number of the first processing circuits, and the number of the relays are equal to the number of the proximity sensors; the number of the second signal generators and the number of the second processing circuits are less than the number of the proximity sensors.

[0037] The second end of the second signal generator is connected in parallel with a plurality of relays; the first end of the second amplifier is connected in parallel with a plurality of proximity sensors.

[0038] The quantitative relationship between the second signal generator and the proximity sensor is shown in the following formula:

[0039]

[0040] Wherein, s is the number of the second signal generators, n is the number of the proximity sensors, and [] indicates taking the integer part of the number in the brackets.

[0041] The quantitative relationship between the second processing circuit and the proximity sensor is shown in the following formula:

[0042]

[0043] Wherein, t is the number of the second processing circuits, n is the number of proximity sensors, and [] indicates taking the integer part of the number in brackets.

[0044] The quantitative relationship between the second analog-to-digital converter and the proximity sensor is shown in the following formula:

[0045]

[0046] Wherein, m is the number of the second analog-to-digital converters, n is the number of the proximity sensors, and [] indicates taking the integer part of the number in the brackets.

[0047] The number of decoders is equal to the number of second signal generators.

[0048] The main controller has the functions of controlling the frequency setting and modification of the first signal generator and the second signal generator, controlling the on and off of the first signal generator and the second signal generator, controlling the operation of the decoder, and receiving the digital inductance signal. Among them, the frequency setting is to uniformly set the initial frequency of each proximity sensor channel through the main controller software; the frequency modification is to modify the initial frequency in the main controller software; in controlling the on and off of the first signal generator or the second signal generator, the main controller sets the initial frequency of the first signal generator or the second signal generator to non-zero, which can generate an excitation source; the main controller sets the initial frequency of the first signal generator or the second signal generator to 0, which can disconnect the excitation source; when controlling the operation of the decoder, turning on the decoder enable end and giving different digital quantities to the control pins of the decoder can control the operation of the decoder; selecting the first analog-to-digital converter or the second analog-to-digital converter can normally receive the proximity sensor inductance signal.

[0049] The first signal generator and the second signal generator mainly generate sinusoidal wave frequency signals to provide the required excitation source for the proximity sensor.

[0050] The first processing circuit and the second processing circuit mainly amplify and filter the collected inductance value in the form of voltage to provide input signals suitable for the first analog-to-digital converter and the second analog-to-digital converter.

[0051] The first analog-to-digital converter and the second analog-to-digital converter mainly convert the analog inductance signal into a digital inductance signal.

[0052] The decoder is mainly selected through the input end to ensure that one of the output ends of the second signal acquisition circuit works.

[0053] The relay mainly receives the set 1 signal from the decoder and connects the circuit where the relay is located.

[0054] The first signal acquisition circuit of a proximity sensor is as follows Figure 1 As shown, the circuit excitation end refers to the circuit end of the proximity sensor receiving the signal, and the signal feedback end refers to the circuit end of the proximity sensor feedback signal. The proximity sensor is a passive, two-wire inductive proximity sensor, which consists of a stainless steel shell, a magnetic core contained in the shell, and a coil wound on the magnetic core. When the excitation signal generated by the first signal generator or the second signal generator flows through the proximity sensor coil assembly, the coil in the proximity sensor will generate a magnetic field. When the target moves toward the proximity sensor, the distance between the proximity sensor and the target changes, causing the magnetic resistance of the proximity sensor coil loop to change, thereby affecting the change in the coil inductance. The generated inductance value is transmitted to the acquisition channel of the main controller in the form of analog voltage after amplification, filtering and analog-to-digital conversion. The main controller obtains the corresponding inductance value according to the algorithm.

[0055] like Figure 2For the same proximity sensor, the hardware is equivalent to setting up two loops, where Figure 2 Processing circuit and Figure 1 The processing circuit in is the same as that in the circuit, including an amplifier and a low-pass filter. The receiving and feedback circuit of the proximity sensor signal when the normal road finger circuit does not fail is the first signal acquisition circuit; the receiving and feedback circuit of the proximity sensor signal after the road finger circuit fails is added, that is, the second signal acquisition circuit. In order to ensure the service life of components, in the initial state, the first signal generator and the first analog-to-digital converter in the first signal acquisition circuit are connected in the main controller software, and the second signal generator and the second analog-to-digital converter in the second signal acquisition circuit are disconnected to ensure that the first signal acquisition circuit works and the service life of the components of the second signal acquisition circuit is not affected. When the main controller cannot receive the inductance signal of the proximity sensor of the first signal acquisition circuit, it is considered that the first signal acquisition circuit is faulty. Considering that if the fault occurs in the first analog-to-digital converter, the first signal generator can still send out a normal excitation source. At this time, there will be two excitation sources in the circuit acting on the same proximity sensor at the same time. This situation is not allowed. Therefore, it is necessary to disconnect the first signal generator and the first analog-to-digital converter in the first signal acquisition circuit in the main controller software and connect the second signal generator and the second analog-to-digital converter in the second signal acquisition circuit. At the same time, it is necessary to turn on the decoder enable terminal, give the corresponding digital quantity to the control pin of the decoder, control the decoder output pin connected to the corresponding relay to 1, and power on the corresponding relay. Only then can the second signal acquisition circuit be fully connected to ensure that the excitation source generated by the second signal generator passes through the proximity sensor, so that the main controller can still receive the correct inductance signal of the proximity sensor. See the flowchart of automatic switching from normal operation of the above circuit to failure. Figure 5 shown.

[0056] like Figure 3 The figure shows the first signal acquisition circuit diagram of 8 proximity sensors. Each proximity sensor has an inductance value generation and inductance value acquisition process. Considering that the proximity sensor and the circuit have been working for a long time, the components have aged and the parameters of the components in the circuit assembly have drifted. When it is close, it will be displayed as far away, and when it is far away, it will be displayed as close. In addition, the proximity sensor is installed outside the body and is susceptible to lightning strikes, which may cause signal overvoltage and overcurrent in the internal circuit, resulting in failure of the acquisition circuit (the inductive proximity sensor has a simple internal structure, no wearing parts, and a long service life. Therefore, the possibility of failure is very small, so failure caused by the proximity sensor itself is not considered). In order not to affect the normal operation of the circuit, an alternative circuit design is required for the acquisition circuit. See Figure 4The first signal acquisition circuit and the second signal acquisition circuit of the eight proximity sensors shown in the figure (ADCz represents the second analog-to-digital converter, signal generator z1 represents the second signal generator, and processing circuits z1 and z2 are second processing circuits). Compared with the full double-redundancy circuit, this embodiment adopts a smaller ratio number for redundant acquisition circuit design, such as Figure 4 The ratio of the number of proximity sensors to the number of second signal generators is 8:1, and the ratio of the number of proximity sensors to the number of second processing circuits is 4:1.

[0057] Figure 4 A second signal acquisition circuit is added. Considering the service life of the electronic components of the second signal acquisition circuit, in the initial state, the first signal generator and the first analog-to-digital converter of the first signal acquisition circuit of each proximity sensor are set to the on state through the main controller software (the initial non-zero frequency of the first signal acquisition circuit channel is uniformly set in the ARM end software of the main controller and sent to the main controller via the bus. The main controller controls the first signal generator to generate a sine wave of the frequency to act on the circuit through the SPI interface, and the corresponding position of the control register in the first signal generator is set to 0 through the software to ensure that the first signal generator can emit a normal frequency), so as to ensure the normal working state of the proximity sensor; the second signal generator and the second analog-to-digital converter of the second signal acquisition circuit are set to the off state (the initial zero frequency of the second signal acquisition circuit channel is uniformly set in the ARM end software of the main controller and sent to the main controller via the bus. The main controller controls the second signal generator to generate a zero-frequency sine wave to act on the circuit through the SPI interface or the corresponding position of the control register in the second signal generator is set to 1 through the software to shield the second signal generator from emitting a normal frequency), so as to ensure that the second signal acquisition circuit is in a non-working state.

[0058] When the main controller cannot receive the inductance value signal (in the form of a voltage signal) of the jth proximity sensor, it is considered that the first signal acquisition circuit of the jth proximity sensor is faulty. At this time, the main controller controls the first signal generator and the first analog-to-digital converter of the jth proximity sensor to be disconnected (in the main controller, the initial frequency of the first signal generator of the jth proximity sensor is modified to 0, or the corresponding position of the control register in the first signal generator of the jth proximity sensor is set to 1 through software to shield the first signal generator of the jth proximity sensor from emitting a normal frequency), ensuring that the first signal generator of the jth proximity sensor no longer continues to send a sine wave signal and no longer collects the inductance value signal fed back by the first analog-to-digital converter of the jth proximity sensor, and at the same time, the second signal generator and the second analog-to-digital converter of the jth proximity sensor are connected The method comprises the following steps: (setting the corresponding frequency of the second signal generator of the jth proximity sensor to non-zero through software, and setting the corresponding position of the control register in the second signal generator of the jth proximity sensor to 0 in the software to turn on the second signal generator of the jth proximity sensor to ensure that the normal frequency is emitted) to provide a signal source for the jth proximity sensor, and at the same time turning on the decoder enable terminal, giving the corresponding digital quantities to the three control pins of the decoder, controlling the output pin of the decoder connected to the corresponding relay to be set to 1, and powering on the relay to ensure that the excitation source generated by the second signal generator of the jth proximity sensor passes through the proximity sensor, and the inductance value of the jth proximity sensor can be collected through the second analog-to-digital converter of the jth proximity sensor, so that the main controller can still receive the inductance value of the jth proximity sensor, and the system can work normally; j=1, 2, ..., 8.

[0059] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

Claims

1. A proximity sensor signal acquisition system, characterized in that: include: A main controller, a first signal acquisition circuit, and a second signal acquisition circuit; The first signal acquisition circuit includes a first signal generator, a first processing circuit, and a first analog-to-digital converter. The first processing circuit includes a first amplifier and a first low-pass filter. The first end of the first signal generator is connected to the main controller, and the second end of the first signal generator is connected to the proximity sensor. The first end of the first amplifier is connected to the proximity sensor, the second end of the first amplifier is connected to the first end of the first low-pass filter, the second end of the first low-pass filter is connected to the first end of the first analog-to-digital converter, and the second end of the first analog-to-digital converter is connected to the main controller. The second signal acquisition circuit includes a second signal generator, a second processing circuit, a second analog-to-digital converter, a decoder, and a relay. The second processing circuit includes a second amplifier and a second low-pass filter. The first end of the second signal generator is connected to the main controller, the second end of the second signal generator is connected to the first end of the relay, the second end of the relay is connected to the proximity sensor, the first end of the decoder is connected to the main controller, and the second end of the decoder is connected to the third end of the relay. The first end of the second amplifier is connected to the proximity sensor, the second end of the second amplifier is connected to the first end of the second low-pass filter, the second end of the second low-pass filter is connected to the first end of the second analog-to-digital converter, and the second end of the second analog-to-digital converter is connected to the main controller. The number of the first signal generators, the number of the first processing circuits, and the number of the relays are equal to the number of the proximity sensors; the number of the second signal generators and the number of the second processing circuits are less than the number of the proximity sensors; The second end of the second signal generator is connected in parallel to a plurality of the relays; and the first end of the second amplifier is connected in parallel to a plurality of proximity sensors.

2. The proximity sensor signal acquisition system according to claim 1, characterized in that: The quantitative relationship between the second signal generator and the proximity sensor is shown in the following formula: Wherein, s is the number of the second signal generators, n is the number of the proximity sensors, and [] indicates taking the integer part of the number in the brackets.

3. The proximity sensor signal acquisition system according to claim 1, characterized in that: The quantitative relationship between the second processing circuit and the proximity sensor is shown in the following formula: Wherein, t is the number of the second processing circuits, n is the number of the proximity sensors, and [] indicates taking the integer part of the number in the brackets.

4. A proximity sensor signal acquisition method, characterized in that: The method is carried out by using the proximity sensor signal acquisition system according to any one of claims 1 to 3, The process includes: Connecting the first signal generator, the first processing circuit, and the first analog-to-digital converter of the n proximity sensors, disconnecting the decoder, disconnecting the second signal generator, the second processing circuit, the second analog-to-digital converter, and the relay of the n proximity sensors, and collecting the signals of the n proximity sensors; When the main controller cannot receive the signal from the i-th proximity sensor, the first signal generator, the first processing circuit, and the first analog-to-digital converter of the i-th proximity sensor are disconnected, the decoder is turned on, and the second signal generator, the second processing circuit, the second analog-to-digital converter, and the relay of the i-th proximity sensor are connected, i=1, 2, ..., n.

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