CN210719210U

CN210719210U - Multi-channel proximity sensor digital resolving module

Info

Publication number: CN210719210U
Application number: CN201921749576.2U
Authority: CN
Inventors: 何兴雷; 张竹; 陈虹屹; 方晟譞; 赵静; 周小社; 其他发明人请求不公开姓名
Original assignee: Chengdu CAIC Electronics Co Ltd
Current assignee: Chengdu CAIC Electronics Co Ltd
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-06-09
Anticipated expiration: 2029-10-18

Abstract

The utility model discloses a module is solved to multichannel proximity sensor digit aims at solving under the multichannel state proximity sensor digit longer problem of time of resolving. The utility model discloses a following technical scheme realizes: in the calculation of the corresponding inductance value of the multi-channel proximity sensor, each path of signal conditioning circuit receives signals from the corresponding connected proximity sensor and is processed into a digital signal state through filtering and amplification; the AC response signal generated by the proximity sensor sends the sensor signals of different channels to the A/D sampling circuit by switching the multi-channel switch, the channel switching and controlling circuit carries out digital processing on the analog signal sent by the multi-channel switch under the control time sequence of the CPU, and the A/D converting circuit outputs a binary number value corresponding to the AC signal; the CPU circuit receives the binary numerical value sent by the A/D conversion circuit, and Fast Fourier Transform (FFT) is carried out on the multipoint sampling value to calculate the corresponding inductance value.

Description

Multi-channel proximity sensor digital resolving module

Technical Field

The utility model relates to a module is solved to multichannel proximity sensor digit that can use on the airborne equipment.

Technical Field

Inductive sensing is a non-contact measurement technique that can be used to accurately measure the position, motion, or composition of a metal or conductive target, and can also be used to detect compression, tension, or torsion of a spring. The inductive proximity sensor is a sensor for measuring the relative position relationship between objects, and is widely applied to the positions of an aircraft landing gear, a cabin door and the like in the field of aviation, and information such as the position of the landing gear, the closing state of the cabin door and the like is measured. The basic principle is that the change of the position between the sensor and the target is utilized to cause the change of the induction inductance value, and the induction inductance value can be introduced into a back-end signal processing circuit to carry out measurement processing. In the existing aviation equipment, two modes of analog circuit processing and digital calculation are adopted for signal processing of the proximity sensor. Since analog signals are more complex to process than digital signals, and the immunity to interference is also weaker than digital signals. Although the analog circuit processing mode has simple circuit structure and high processing speed, the analog circuit processing mode has no digital interface, has complex equipment, large size and high cost, and does not meet the digital requirement of the current aviation equipment, so the analog circuit processing mode is gradually eliminated. The digital calculation mode is applied to the existing aviation equipment, but because the number of proximity sensors installed on the existing large-scale aircraft is large, and the requirement of the aircraft on the real-time performance of the sensor information is high, the digital calculation equipment for the proximity sensors used on the existing operating aircraft mainly adopts single-channel calculation to ensure the real-time performance of the sensor information in a mode of digitally calculating a single sensor, and the digital calculation time of the proximity sensors in a multi-channel state is long. In the process of data acquisition of the digital displacement sensor, the acquired data only qualitatively reflect the change condition of the displacement, and if the digital displacement sensor is required to be well adapted to a system, the data after multiple codes are required to be processed. The processing method comprises filtering, scale transformation and data fitting. In the actual testing process, the final result is deviated due to the phenomenon that the sensor shakes during the application. These disturbances are mainly manifested in errors in the encoded data, cannot be eliminated by filtering the electrical signal, and can only be eliminated or reduced by a specific digital filter structure. It is known domestically that there are no integrated multi-channel proximity sensor digital solvers applied to aircraft.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the purpose is to solving under the multichannel state proximity sensor digit and resolving the longer problem of time and the multichannel proximity sensor digit that provides and resolving the module based on satisfying the aviation field to sensor information real-time demand.

The utility model discloses an above-mentioned purpose can be reached through following measure, a module is solved to multichannel proximity sensor digit, include: connect n signal conditioning circuit, the channel that connects signal conditioning circuit output of way proximity sensor and switch and control circuit, CPU circuit, monitoring circuit and power supply circuit, its characterized in that: the CPU circuit at least is internally provided with a program memory, a data memory, a bus interface, an I/O interface, an A/D data bus, a clock, a reset, a 4-way sin, pwm1, a 1-way 422 bus, and a digital signal processor DSP for outputting control signals of a multi-way switch and control signals of a 1 piece of AD7656 chip; each signal conditioning circuit receives signals from the corresponding connected proximity sensors, and the signals are filtered and amplified to be in a signal state capable of being processed digitally, and alternating current signals generated by the proximity sensors are sent to the multi-way switch; in the control of channel switching, a synchronous control mechanism of switching control and excitation signal linkage is adopted, the channel switching and control circuit sends sensor signals of different channels to an A/D sampling circuit by switching a multi-channel switch under the control time sequence of a CPU (central processing unit), analog signals sent by the multi-channel switch are subjected to digital processing, the A/D conversion outputs binary values corresponding to the signals, the CPU circuit receives the binary values sent by the A/D conversion circuit, and the inductance values corresponding to the proximity sensors are calculated in a multi-channel centralized mode through fast FFT (fast Fourier transform) numerical calculation.

The utility model discloses following beneficial effect has.

The utility model discloses a connect n way proximity sensor's signal conditioning circuit, the passageway of connecting signal conditioning circuit output switches and control circuit, the CPU circuit, monitoring circuit and power supply circuit, take care of multichannel inductance type proximity sensor signal, signal acquisition, digital processing and corresponding inductance value calculate, the completion carries out rapid processing to multichannel proximity sensor signal, solve work, the mode of the inductance value that proximity sensor corresponds is solved to the digit, solved the analog type and solved the circuit and easily received the interference, the precision is not high, defect such as no digital interface, the technical merit of equipment has been improved. The purpose of meeting the requirements of aviation equipment on high accuracy and real-time performance of the sensor information can be achieved. The functional circuits are composed of a signal conditioning circuit, a channel switching and controlling circuit, an A/D sampling circuit, a CPU circuit, a monitoring circuit and a power supply circuit, different configurations can be carried out among the functional circuits according to different actual use environments, the functional circuits can be placed on different circuits, and correct signal connection is guaranteed.

The utility model discloses on the control that the passageway switches, adopt the binary number value that this signal of synchro control mechanism AD conversion output of switching control and excitation signal linkage corresponds, the CPU circuit receives the binary number value that AD converting circuit sent, through quick FFT transform numerical calculation, the inductance value that proximity sensor corresponds is concentrated to the multichannel, this kind of adopt multichannel to concentrate the solution mode, realized accomplishing resolving 16 way sensors in 40ms on a circuit board, and can expand 32 way passageways, the integrated level of equipment has been improved, compare current single channel formula digital solution equipment, when exceeding 8 way sensors's user demand, can lighten weight, reduce the volume, reduce equipment cost.

Drawings

FIG. 1 is a schematic block diagram of the digital solution module of the multi-channel proximity sensor of the present invention;

FIG. 2 is a functional block diagram of the sensor signal conditioning circuit of FIG. 1;

FIG. 3 is a schematic block diagram of the channel switching and A/D conversion circuit of FIG. 1;

FIG. 4 is a functional block diagram of the CPU circuit of FIG. 1;

fig. 5 is a schematic block diagram of the power supply circuit of fig. 1.

Detailed Description

See fig. 1. In the preferred embodiment described below, all of the functional circuitry of the multi-channel proximity sensor digital solution module in this embodiment is placed on a single circuit board. The multichannel proximity sensor digital resolving module mainly comprises: connect n signal conditioning circuit, the channel of connecting signal conditioning circuit output of way proximity sensor and switch and control circuit, CPU circuit, monitoring circuit and power supply circuit, wherein: the CPU circuit at least is internally provided with a program memory, a data memory, a bus interface, an I/O interface, an A/D data bus, a clock, a reset, a 4-way sin, pwm1, a 1-way 422 bus, and a digital signal processor DSP for outputting control signals of a multi-way switch and control signals of a 1 piece of AD7656 chip; each signal conditioning circuit receives signals from the corresponding connected proximity sensors, and the signals are filtered and amplified to be in a signal state capable of being processed digitally, and alternating current response signals generated by the proximity sensors are sent to the multi-way switch; in the control of channel switching, a synchronous control mechanism of switching control and excitation signal linkage is adopted, the channel switching and control circuit sends sensor signals of different channels to an A/D sampling circuit by switching a multi-channel switch under the control time sequence of a CPU, analog signals sent by the multi-channel switch are subjected to digital processing, the A/D conversion outputs binary values corresponding to the signals, the CPU circuit receives the binary values sent by the A/D conversion circuit, the inductance values corresponding to the proximity sensors are intensively solved by multi-channel through fast FFT conversion numerical calculation, and simultaneously, all calculation and control logics are executed by software resident in a DSP,

because the proximity sensor sends 1Khz alternating current signals, the A/D conversion circuit adopts a fast sampling mode to finish 64 times of sampling and conversion within 1 ms. The CPU circuit adopts a digital signal processor DSP28335 as a processor, receives the binary numerical value sent by the A/D conversion circuit, and calculates the inductance value corresponding to the sensor through numerical calculation such as fast FFT conversion. Meanwhile, the control and scheduling of the hardware are also performed by the digital signal processor DSP. All computation and control logic is executed by software running resident in the DSP processor. The power circuit is used for converting an externally input 28V direct current power supply into various secondary power supplies required by the operation of the resolving module circuit, such as +5V, + -15V, 3.3V, 1.9V and the like.

The monitoring circuit is effectively another set of a/D sampling and DSP circuits described above that also perform the above operations simultaneously.

See fig. 2. The signal conditioning circuit includes: the precise resistance is connected with the proximity sensor, the follower is connected with the precise resistance in parallel, the first digital selector MUX (alternative one) and the first filter are connected in series, the first digital selector MUX is connected with the connection line of the input end of the precise resistance in parallel through the parallel connection point connection line of the precise resistance and the follower, the second digital selector MUX (alternative one) and the second filter are connected in series, the second digital selector MUX is connected with the connection line of the input end of the precise resistance in common end, the parallel connection point connection line of the precise resistance and the follower, the second digital selector MUX is connected in series, the filter uses a general amplifier F124 to form a low-pass filter, and the cut-off frequency is set to be 2 kHz. The signal conditioning circuit is mainly based on the principle of an impedance measurement method of an inductor, a standard resistor is connected with a proximity sensor in series, a follower applies 1 sine wave excitation, and signals at two ends of the standard resistor are measured and amplified and filtered and then respectively sent to a channel switching circuit. In order to ensure the consistency of signal processing of the same sensor, two signals at two ends of the same standard resistor are sent to an electronic switch DG419, a low-pass filter and an A/D (analog/digital) device at a time-sharing later stage, so that the characteristics of signal conditioning circuits are consistent and deviation is avoided for the same sensor.

See fig. 3. The channel switching and controlling circuit includes: the proximity sensor comprises a digital selector MUX (1 in 8) and an analog-to-digital A/D converter which are input after signal processing of the proximity sensor, and a CPU processor which is connected with the I/O of the CPU through a CPU bus at the output end of the A/D converter. The processed analog signal of the proximity sensor is sent to a channel switching circuit of a channel switching and controlling circuit, and the circuit can use a DG408 chip digital selector MUX (8-to-1) which inputs 8 channels and outputs 1 channel of electronic switches as a switching electronic switch. The 1 DG408 can switch the signals of 8 proximity sensors, and the number of DG408 can be expanded as needed to expand the number of external sensors. The output of the electronic switch DG408 is sent to an a/D conversion circuit, and the converted binary value is stored in a buffer memory in the AD7656 and read by the CPU. The A/D converter can adopt an AD7656 chip which is a 16-bit 6-input-channel analog-to-digital converter, the conversion rate can reach 250KHz, and the rapid conversion of analog signals can be realized. Because the signals at the two ends of the standard resistor are sent to the electronic switch of the switching circuit in a time-sharing manner, in order to ensure the consistency of the acquisition phases of the two alternating current signals, a synchronous control mechanism is adopted in the control of the switching circuit, and the alternating current excitation signal synchronously controls the channel switching and starts the A/D conversion, so that the same initial phase of each A/D sampling can be ensured, and the consistency of the numerical calculation of the multi-channel sensor is also ensured. The synchronization control mechanism also requires the involvement of CPU circuitry.

See fig. 4. The CPU may employ a TMS320F28335 digital processor. The program memory is provided with working software for completing the work of inductance value calculation of the sensor, control logic setting of hardware control, scheduling and the like. The inductance value of the proximity sensor is calculated by performing Fast Fourier Transform (FFT) on multipoint sampling values according to an impedance measurement method.

See fig. 5. The power supply circuit is used for converting an input 28V direct current power supply into a secondary power supply required by other functional circuits, and comprises an anti-reverse diode, a DC/D C secondary power supply outputting +5V and +/-15V, an LDO power supply module outputting 3.3V and 1.9V and the like which are sequentially connected in series, wherein the ZHDC12S05/12W power supply module can be used for converting the 28V power supply into the +5V power supply, the ZSAH28D15F/5W power supply module can be used for converting the 28V power supply into the +/-15V power supply, the LDO power supply module converting +5V into +3.3V and +1.9V can select 76TPS 7D301PWP, and the power supply modules can provide current required by a load circuit.

The above description is for the purpose of describing the invention in more detail and in connection with the preferred embodiments, and it is not to be construed that the embodiments are limited thereto, and it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A multi-channel proximity sensor digital solution module comprising: connect n signal conditioning circuit, the channel that connects signal conditioning circuit output of way proximity sensor and switch and control circuit, CPU circuit, monitoring circuit and power supply circuit, its characterized in that: the CPU circuit at least is internally provided with a program memory, a data memory, a bus interface, an I/O interface, an A/D data bus, a clock, a reset, a 4-way sin, pwm1, a 1-way 422 bus, and a digital signal processor DSP for outputting control signals of a multi-way switch and control signals of a 1 piece of AD7656 chip; each signal conditioning circuit receives signals from the corresponding connected proximity sensors, and the signals are filtered and amplified to be in a signal state capable of being processed digitally, and alternating current signals generated by the proximity sensors are sent to the multi-way switch; the channel switching and controlling circuit sends sensor signals of different channels to the A/D sampling circuit by switching the multi-way switch under the control time sequence of the CPU, and adopts a synchronous control mechanism of linkage of switching control and excitation signals under the control time sequence of the CPU in the aspect of channel switching control; the analog signals sent by the multi-way switch are processed digitally, and the A/D conversion circuit outputs binary values corresponding to the alternating current signals; the CPU circuit receives the binary numerical value sent by the A/D conversion circuit, and Fast Fourier Transform (FFT) is carried out on the multipoint sampling value to calculate the corresponding inductance value.

2. The multi-channel proximity sensor digital solution module of claim 1, wherein: the A/D conversion circuit adopts a fast sampling mode and completes 64 times of sampling and conversion within 1 ms.

3. The multi-channel proximity sensor digital solution module of claim 1, wherein: the CPU circuit adopts a digital signal processor DSP28335 as a processor, receives the binary numerical value sent by the A/D conversion circuit, and calculates the inductance value corresponding to the sensor through numerical calculation such as fast FFT conversion.

4. The multi-channel proximity sensor digital solution module of claim 1, wherein: the control and scheduling of hardware is performed by a digital signal processor DSP and all computation and control logic is performed by software running resident in the DSP processor.

5. The multi-channel proximity sensor digital solution module of claim 1, wherein: the signal conditioning circuit includes: the precise resistance is connected with the proximity sensor, the follower is connected with the precise resistance in parallel, the first digital selector MUX is connected with the connection line of the input end of the precise resistance in parallel through the parallel connection point connection line of the precise resistance and the follower, the first filter is connected with the first digital selector MUX in series, the second digital selector MUX is connected with the connection line of the input end of the precise resistance in series through the parallel connection point connection line of the precise resistance and the follower, and the second filter is connected with the second digital selector MUX in series.

6. The multi-channel proximity sensor digital solution module of claim 1, wherein: the filter is a low-pass filter formed by using a general-purpose amplifier F124, and the cutoff frequency is set to 2 kHz.

7. The multi-channel proximity sensor digital solution module of claim 1, wherein: the signal conditioning circuit is characterized in that a standard resistor is connected with a proximity sensor in series according to the principle of an impedance measurement method of an inductor, 1 sine wave excitation is applied to a follower, and signals at two ends of the standard resistor are measured and amplified and filtered and then sent to a channel switching circuit respectively.

8. The multi-channel proximity sensor digital solution module of claim 1, wherein: the channel switching and controlling circuit includes: the 8-to-1 digital selector MUX is input after the proximity sensor signal is processed, the analog-to-digital A/D converter is connected with the MUX, and the CPU processor is connected with the I/O of the CPU through a CPU bus at the output end of the A/D converter; and the processed analog signal of the proximity sensor is sent to a channel switching circuit of the channel switching and controlling circuit.

9. The multi-channel proximity sensor digital solution module of claim 1, wherein: the channel switching circuit uses one input 8 channels, a DG408 chip number selector MUX (8-to-1) of the electronic switch of 1 output channel is used as a switched electronic switch, and 1 DG408 switches signals of 8 proximity sensors; the output of the electronic switch DG408 is sent to an a/D conversion circuit, and the converted binary value is stored in a buffer memory in the AD7656 and read by the CPU.

10. The multi-channel proximity sensor digital solution module of claim 1, wherein: the program memory is resident with working software for completing the inductance value calculation of the sensor, hardware control and scheduling, and control logic setting, and the proximity sensor calculates the corresponding inductance value by performing Fast Fourier Transform (FFT) on the multipoint sampling value.