CN112880729A - Device and method for detecting performance of absolute position sensor of maglev train - Google Patents
Device and method for detecting performance of absolute position sensor of maglev train Download PDFInfo
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Abstract
The invention discloses a performance detection device and method for an absolute position sensor of a maglev train, which comprises a positioning mark plate, a code reader U-shaped groove, a detection coil controller, a detection coil mounting bracket, a detection coil adjusting bracket, a simulator and an observation computer, wherein the positioning mark plate is arranged at the lower end of the detection coil adjusting bracket, the positioning mark plate comprises a detection coil and a printed circuit board, the detection coil is composed of a plurality of groups of sub-coils and is arranged between a transmitting coil and a receiving coil of the absolute position sensor, and the detection coils are arranged on the front and back sides of the printed circuit board according to a certain interval size, and are connected with an observation computer through a detection coil controller, and the detection coil controller is connected with each group of sub-coils in the detection coils through a high-speed analog switch. The invention can simply, accurately and conveniently realize the performance evaluation of the absolute position sensor.
Description
Technical Field
The invention belongs to the technical field of maglev trains, and particularly relates to a performance detection device and method for an absolute position sensor of a maglev train.
Background
The absolute position sensor is an important component of a positioning and speed measuring system of a high-speed magnetic-levitation train, and the absolute position of the train running on the track is obtained by testing the sensor. In order to ensure the engineering test and production of the absolute position sensor and realize the synchronous traction control and safe operation of the magnetic-levitation train, the operating state of the absolute position sensor, particularly the code reading information of the absolute position sensor, needs to be accurately obtained in real time.
To ensure the accuracy of the code reading information of the absolute position sensor, firstly, before the absolute position sensor is formally arranged in a train, the quality of the absolute position sensor needs to be necessarily detected so as to ensure that the absolute position sensor meets the requirements of a position detection system. Secondly, the absolute position sensor is exposed for a long time, and although a certain protection device is provided, some faults may occur after the sensor works for a period of time due to the fact that the working environment is complex and severe, and at the moment, necessary maintenance and updating are required to be carried out on the sensor in time.
The existing detection method for the absolute position sensor only comprises the step that a hand-held positioning mark plate passes through a U-shaped groove of a code reader to carry out manual detection. Although the mode is simple and convenient, the code reading performance of the sensor when the train runs at high speed cannot be simulated, and the influence of the positioning mark plate on the code reading of the sensor when the positioning mark plate enters the U-shaped groove at different high speeds and postures cannot be simulated.
Therefore, how to simulate the code reading process of the absolute position sensor when the train passes through the positioning sign board under different speeds and working conditions under the static condition, and further test the performance of the absolute position sensor becomes a technical problem which needs to be solved by the technical personnel in the field.
Disclosure of Invention
The invention aims to provide a device and a method for detecting the performance of an absolute position sensor of a maglev train, which can simply, accurately and conveniently evaluate the performance of the absolute position sensor, and avoid the defects in the prior art.
One of the purposes of the invention is realized by the following technical scheme: the detecting coil is arranged at the lower end of the detecting coil adjusting bracket and can transversely, vertically and longitudinally move in the detecting coil U-shaped groove, the positioning mark plate comprises a detecting coil and a printed circuit board, the detecting coil is composed of a plurality of groups of sub-coils and is arranged between a transmitting coil and a receiving coil of the absolute position sensor, and the plurality of groups of sub-coils are arranged on the front surface and the back surface of the printed circuit board according to a certain interval size, the detection coil is connected with an observation computer through a detection coil controller, the detection coil controller is connected with each group of sub-coils in the detection coil through a high-speed analog switch, and the simulator is respectively connected with the positioning mark plate and the observation computer.
As a further improvement, the multiple groups of sub-coils are divided into multiple groups of positioning coils and multiple groups of code reading coils, each group of positioning coils and each group of code reading coils are composed of a plurality of coil units, and each coil unit is controlled to be switched on and off by a high-speed analog switch.
As a further improvement, the detection coil adjusting bracket at least comprises a sliding block, a vertical screw and two guide rails, wherein the two guide rails are transversely parallel and fixed on the detection coil mounting bracket at intervals, the sliding block is longitudinally arranged and can slide on the two guide rails, the vertical screw vertically penetrates through the sliding block and can longitudinally and vertically move on the sliding block, and the positioning mark plate is fixed at the lower end of the vertical screw.
As a further improvement, the detection coil adjusting bracket further comprises a first driving mechanism, and the first driving mechanism is respectively connected with the sliding block and the observation computer; and/or the detection coil adjusting bracket further comprises a second driving mechanism, and the second driving mechanism is respectively connected with the vertical screw and the observation computer; and/or the detection coil adjusting support further comprises a third driving mechanism, and the third driving mechanism is respectively connected with the vertical screw and the observation computer.
As a further improvement, the detection coil mounting bracket is of a three-dimensional frame structure, the code reader U-shaped groove is transversely fixed at the bottom of the three-dimensional frame structure, and the two guide rails are fixed at the top of the three-dimensional frame structure.
As a further improvement, the high-speed analog switch is controlled by a programmable logic device FPGA, which is specifically represented as: and the programmable logic device FPGA inputs high electric frequency to the high-speed analog switch to conduct the corresponding sub-coil, and the programmable logic device FPGA inputs low level to the high-speed analog switch to disconnect the corresponding sub-coil.
As a further improvement, the detection coil controller simulates the area of the transmitting coil and the receiving coil which are shielded by the copper foil when the positioning mark plate passes through the absolute position sensor through the number of the sub-coils in the detection coil communicated with the high-speed analog switch.
As a further improvement, the speed of the magnetic suspension train passing through the absolute position sensor is simulated by controlling the time in each code reading process, so that the performance of reading the absolute position code by the absolute position sensor at different speeds is detected.
The second purpose of the invention is realized by the following technical scheme: the performance detection method of the absolute position sensor of the maglev train is provided, and detection is carried out based on any absolute position sensor performance detection device of the maglev train, and the detection method comprises the following steps:
the method comprises the following steps that firstly, a detection coil is adjusted to adjust a support to place a positioning mark plate to a preset initial position;
secondly, the observation computer sends a control instruction to the detection coil through the detection coil controller, and the on-off of the sub-coil in the detection coil is changed through the high-speed analog switch, so that the received signal of the receiving coil is changed, the signal reading of the receiving coil is controlled, and the analog control of the code reading value of the absolute position sensor is realized;
thirdly, the observation computer receives and processes the positioning mark plate code reading speed signal and the position signal which are transmitted back by the simulator;
step four, repeating the step one to the step three until the absolute position sensor finishes the code reading of the positioning mark plate in one period;
and step five, the observation computer evaluates the performance and the quality of the absolute position sensor according to the obtained code reading result.
As a further improvement, the implementation of analog control of the read code value of the absolute position sensor in the second step is specifically represented as: the on-off speed of the coil is changed by sending a control instruction through the observation computer, so that the code reading speed of the absolute position sensor is changed; the control instruction is sent by the observation computer, the on-off quantity of the coils is adjusted by the high-speed analog switch, and the code reading performance of the sensor of the positioning mark plate under different heights and different postures is tested.
The invention comprises a positioning mark plate, a code reader U-shaped groove, a detection coil controller, a detection coil mounting bracket, a detection coil adjusting bracket, a simulator and an observation computer, wherein: the detection coil adjusting bracket is arranged on the detection coil mounting bracket in a sliding way, the code reader U-shaped groove is arranged below the detection coil mounting bracket, the positioning mark plate is arranged at the lower end of the detection coil adjusting bracket, the detection coil adjusts the support to move transversely, vertically and longitudinally in the U-shaped groove of the code reader, the positioning mark plate comprises a detection coil and a printed circuit board, the detection coil consists of a plurality of groups of sub-coils and is arranged between a transmitting coil and a receiving coil of the absolute position sensor, and the multiple groups of sub-coils are arranged on the front and back sides of the printed circuit board according to a certain interval size, the detection coils are connected with an observation computer through a detection coil controller, the detection coil controller is connected with each group of sub-coils in the detection coils through a high-speed analog switch, and the simulator is respectively connected with the positioning mark plate and the observation computer. The process that the positioning mark plate passes through the U-shaped groove of the code reader is simulated by controlling the on-off of the neutron coil of the detection coil through the high-speed simulation switch, so that the absolute position code is read, and the method has the advantages of simplicity, convenience, high efficiency and accuracy in performance evaluation of the absolute position sensor.
Drawings
The invention is further illustrated by means of the attached drawings, but the embodiments in the drawings do not constitute any limitation to the invention, and for a person skilled in the art, other drawings can be obtained on the basis of the following drawings without inventive effort.
Fig. 1 is a schematic diagram of a code reading mode based on large coil positioning and small coil positioning.
Fig. 2 is a schematic structural diagram of an absolute position sensor performance detection device of a magnetic-levitation train.
Fig. 3 is a schematic diagram of a transmit coil.
Fig. 4 is a schematic diagram of the coupling of the transmitting coil and the detecting coil.
Fig. 5 is a detection coil arrangement diagram.
Fig. 6 is an analog switch control schematic.
FIG. 7 is a side view offset up and down from a standard position.
FIG. 8 is a schematic diagram of the on/off of the detector coil.
Fig. 9 is a flow chart of a method for detecting absolute position sensor performance of a magnetic-levitation train.
Description of reference numerals:
1. the device comprises a detection coil mounting support, 2, a code reader U-shaped groove, 3, a guide rail, 4, a sliding block, 5, a vertical screw, 6, a horizontal sliding groove, 7, a positioning mark plate, 71, a detection coil, 72, a printed circuit board, 8, a detection coil controller, 9, an observation computer, 10 and a simulator
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings and specific embodiments, and it is to be noted that the embodiments and features of the embodiments of the present application can be combined with each other without conflict.
For a better description of the invention, the code reading process of the absolute position sensor is explained in detail before the simulation of the code reading process of the absolute position sensor. In the prior art, a positioning mark plate is a plastic plate with a certain thickness, the middle layer is coated with copper, and a coding narrow slit for representing position information is reserved according to a certain rule. The copper-clad (shielding layer) on the positioning mark plate is divided into 5 binary regions with the same height, 4 coding narrow gaps with the same size and 3mm wide, each coding narrow gap corresponds to one bit of binary code, relative to the geometric center of the binary system, the coding narrow gap deviated to the left of the center is '1' of the binary system, the coding narrow gap deviated to the right of the center is '0' of the binary system, and the adjacent mark plates adopt gray codes for absolute coding, so that the coding reliability is effectively improved. Gray code is an unauthorized code, and is characterized in that only one digit is different between any two adjacent codes, and the read code can be verified according to the rule.
The code reading mode based on the large coil positioning and the small coil positioning in fig. 1 is taken as an example. The code reading mode based on large coil positioning and small coil code reading refers to that: the position of the positioning mark plate in the U-shaped groove of the code reader is judged through eight large coils, so that the code reading time of the small coils is determined to start code reading, the large coils are used for positioning, the small coils are used for reading codes, the code reading process is shown in figure 1, the coils of the code reader are numbered as 1, 2 and 3 … 10, wherein 1, 2, 3, 4, 7, 8, 9 and 10 are large coils, and 5 and 6 are small coils. A1, A2, A3 and A4 are respectively encoding narrow slits of the highest position, the next lowest position and the lowest position of the positioning mark plate, and the encoding of the three positioning mark plates from left to right is 1001, 0001 and 0001 according to the encoding definition rule of the positioning mark plates.
Let each receiving coil voltage be u1、u2、u3…u10It can be seen from fig. 1 that 1, 7, 2, 8, 3, 9, 4, and 10 are four sets of corresponding positioning coil combinations, 5 and 6 are four sets of corresponding positioning coil combinationsAnd a code reading coil. The receiving coil of the absolute position sensor adopts a differential structure, and the actually input comparison voltage is the differential voltage value of each group of positioning coils expressed by lower case letters: u. of17＝u1-u7；u28＝u2-u8；u39＝u3-u9；u410＝u4-u10，u65＝u6-u5. The logic states output by the comparator of each group of positioning coils and code reading coils are respectively expressed as follows by capital letters: u shape17、U28、U39、U410And U65。
When two large coils in a group of positioning coils are shielded to have the same area (half of the shielded area in fig. 1), the coils are used as positioning positions, and the output level of the comparator in the corresponding group jumps, namely, the starting of code reading is triggered. According to the definition rule of the codes on the positioning mark plate, when the coding narrow slot is opposite to the small coil 6, the corresponding code should be '0', and when the coding narrow slot is opposite to the small coil 5, the corresponding code should be '1'.
The process of reading the code based on the large coil positioning and the small coil is described by taking the case that the train runs in the forward direction to completely read the positioning sign board 2 (code 0001) in fig. 1 as an example. When the positioning mark plate does not enter the U-shaped groove of the code reader completely, 10 coils are not shielded, the voltages of the positioning coils and the code reading coils in corresponding groups are basically equal, so that the differential voltage U of each group is approximately equal to 0, and the reference voltage V of each group of comparators is comparedrefSet to a value slightly greater than 0, e.g. 1V, when u < VrefThe output of the comparator is high level, and the logic states of the coils of each group are respectively U17＝U28＝U39＝U410＝〞1″，U 651 ═ 1 ". When the U-shaped groove of the code reader runs to the moment before the position 1, the areas of the positioning coils 1, 2, 3 and 4 of the positioning mark plate are less than half, and the areas of the positioning coils 7, 8, 9 and 10 are more than half, so that the area of the positioning coils is larger than half
At this time, U4100, similarly to U17＝U28＝U39＝U4100 ", and the small coils 5, 6 are U because they are completely shielded65＝〞1〞。
When the U-shaped groove of the code reader runs to the position 1, the shielding areas of the positioning coils 4 and 10 are the same, and U is4-u10≈0，
The output logic state of the group of comparators becomes U410The logic state makes a 0 to 1 transition, initiating a fix and starting a read. At this time, the highest-order coding slit is aligned with the small coil 6, and the small coil 5 is completely shielded,
thus reading the most significant bit of the code as "0".
When the U-shaped groove of the code reader runs to the position 2, the shielding areas of the positioning coils 3 and 9 are the same, and U is3-u9≈0，u39＜Vref39The output logic state of the set of comparators becomes U39The logic state makes a 0 to 1 transition, initiating a fix and starting a read. At this time, the highest-order coding slit is aligned with the small coil 6, and the small coil 5 is completely shielded,
thus reading the next highest bit to encode a "0".
When the U-shaped groove of the code reader runs to the position 3, the shielding areas of the positioning coils 2 and 8 are the same, and U is2-u8≈0，
The output logic state of the group of comparators becomes U28At "1", a 0 to 1 transition occurs in the logic state, initiating a fix and starting a read. At this time, the highest-order coding slit is aligned with the small coil 6, and the small coil 5 is completely shielded,
thus reading the next lower bit as a "0".
When the U-shaped groove of the code reader runs to the position 4, the shielding areas of the positioning coils 1 and 7 are the same, and U is1-u8≈0，
The output logic state of the group of comparators becomes U17At "1", a 0 to 1 transition occurs in the logic state, initiating a fix and starting a code read. At this time, the highest-order coding slit is aligned with the small coil 5, and the small coil 6 is completely shielded,
thereby reading the code of the lowest bit as "1".
Similarly, the codes of the other two positioning mark plates are read to be 1001 and 0001 respectively, so that the code of the group of positioning mark plates is 100100010001, if the running direction of the train is changed, the code reader reads the code values of the lowest position, the next highest position and the highest position in sequence, and the code reader can send the code values to the upper computer only by recombining the code values in combination with the direction judging signal.
The invention discloses a detecting device for the absolute position sensor of a maglev train, which comprises a positioning mark plate 7, a code reader U-shaped groove 2, a detecting coil controller 8, a detecting coil mounting bracket 1, a detecting coil adjusting bracket, a simulator 10 and an observation computer 9, wherein the detecting coil adjusting bracket is arranged on the detecting coil mounting bracket 1 in a sliding way, the code reader U-shaped groove 2 is arranged below the detecting coil mounting bracket 1, the positioning mark plate 7 is arranged at the lower end of the detecting coil adjusting bracket and can transversely, vertically and longitudinally move in the code reader U-shaped groove 2 through the detecting coil adjusting bracket, the positioning mark plate 7 comprises a detecting coil 71 and a printed circuit board 72, the detection coil 71 is composed of a plurality of sub-coils and is placed between a transmitting coil and a receiving coil of the absolute position sensor, the sub-coils are arranged on the front side and the back side of the printed circuit board 72 according to a certain interval size, the detection coil 71 is connected with the observation computer 9 through the detection coil controller 8, the detection coil controller 8 is connected with each sub-coil in the detection coil 71 through a high-speed analog switch, the process that the positioning mark plate 7 passes through the U-shaped groove 2 of the code reader is simulated by controlling the on-off of the sub-coils in the detection coil 71 through the high-speed analog switch, and therefore the reading of the codes of the absolute position sensor is achieved, and the simulator 10 is respectively connected with the positioning mark.
Meanwhile, as shown in fig. 2, the detection coil adjusting bracket at least includes a first driving mechanism, a second driving mechanism, a third driving mechanism, a slider 4, a vertical screw 5 and two guide rails 3, wherein the two guide rails 3 are fixed on the detection coil mounting bracket 1 in a transverse parallel manner and at intervals, the slider 4 is arranged in a longitudinal direction, a horizontal sliding groove 6 is formed in the slider 4 in the longitudinal direction, the slider 4 can slide on the two guide rails 3 by the driving of the first driving mechanism, the vertical screw 5 vertically penetrates through the slider 4 and is arranged, and can slide on the horizontal sliding groove 6 by the driving of the second driving mechanism, and can slide on the slider 4 by the driving of the third driving mechanism. The positioning mark plate 7 is fixed at the lower end of the vertical screw 5, the positions of the sliding block 4 and the vertical screw 5 are adjusted through the first driving mechanism, the second driving mechanism and the third driving mechanism, and then the position of the positioning mark plate 7 in the U-shaped groove 2 of the code reader is adjusted, so that the working condition simulation of detection by the absolute position sensor is completed. Preferably, the first driving mechanism, the second driving mechanism and the third driving mechanism are respectively connected with the observation computer 9, so that the automatic control of the position adjustment of the positioning mark plate 7 is realized; the number of the first driving mechanisms is two, and each guide rail 3 is provided with one first driving mechanism. The first driving mechanism and/or the second driving mechanism and/or the third driving mechanism are preferably hydraulic cylinders, but are not limited thereto, and may also be air cylinders or electric push rods, which are not listed here.
As a preferred embodiment of the present invention, the detection coil mounting bracket 1 has a three-dimensional frame structure, the code reader U-shaped groove 2 is fixed to the bottom of the three-dimensional frame structure in the transverse direction, and the two guide rails 3 are fixed to the top of the three-dimensional frame structure.
The working principle of the absolute position sensor performance detection device is as follows:
as shown in FIG. 3, the absolute position sensor has a transmitting end of a transmitting coil connected in series to a resonant circuit with a coil inductance L1The compensation capacitor is C and the resistor is R1Input voltage of VsFrequency is ω, where R1Including the equivalent resistance of the coil. When the detection coil 71 is open, the current in the transmitting end circuit of the transmitting coil in the absolute position sensor is:
in the formula, j is a repeated expression symbol and does not represent any physical meaning.
When the input voltage frequency reaches the resonant frequency:
and then the current of the transmitting end circuit is as follows: i ═ Vsand/R, the circuit current reaches the maximum.
When the detecting coil 71 is closed, the transmitting coil and the detecting coil 71 in the absolute position sensor form a loose coupling transformer, and the circuit model of the loose coupling transformer is shown in fig. 4. According to the electromagnetic induction principle, the current I1 in the loop of the transmitting end and the current I2 in the detecting coil 71 are as follows:
in the formula (I), the compound is shown in the specification,
represents the coil current at the transmitting end,
Indicating the receiving end coil current, UpIs the voltage of the power supply at the transmitting end,
is the impedance of the transmitting-end circuit, Z2＝R2+j(L2ω) is the detection coil impedance;
is the mutual inductance coefficient; k is a coupling coefficient of 0<k<1。
As can be seen from equation (2), the transmitting-end current decreases when the detection coil 71 is turned on, wherein
Is an inductive impedance. The more the sub-coils in the detection coil 71 are turned on, the higher the inductive impedance is, and the smaller the current at the transmitting end is. The weaker the signal received by the receiver coil in an absolute position sensor is until it can be approximated to 0. In short, the detection coil 71 consumes the energy of the transmission coil, so that the energy obtained by the receiving end becomes smaller.
From the above analysis, it can be seen that: the area of the transmitting coil and the receiving coil which are shielded by the copper foil when the positioning mark plate 7 passes through the absolute position sensor is simulated by turning on the number of the sub-coils in the detection coil 71.
In a further technical scheme, the multiple groups of sub-coils are divided into multiple groups of positioning coils and multiple groups of code reading coils, each group of positioning coils and each group of code reading coils are composed of a plurality of coil units, and each coil unit is controlled to be switched on and switched off by a high-speed analog switch. Preferably, the circuit board dimensions are the same as the prior art signage board dimensions.
In order to be able to simulate the actual reading process of the absolute position sensor, it is necessary to turn on or off the sub-coils in the detection coil 71 in sequence. The sub-coil sequences are mainly divided into two categories: the sensor comprises a positioning coil and a reading coil, wherein the positioning coil is used for simulating the positioning function of the sensor, and the reading coil is used for simulating the reading function of the sensor. Preferably, the two coils do not differ in shape and number of turns. Several groups of code reading coils are corresponding to the transmitting coil and receiving coil of absolute position sensor. Several sets of locator coils correspond to the transmitter coils and receiver coils for absolute position sensor positioning.
Further, there are 8 positioning coils and 2 code reading coils in the absolute position sensor. In order to simulate the working principle of the absolute position sensor, the detection coils 71 in the invention preferably correspond to 8 sets of positioning coils and 2 sets of code reading coils. Each group of positioning coils and code reading coils can be formed by a plurality of coil units according to different requirements. Taking the embodiment shown in fig. 5 as an example, the positioning coils are divided into 8 groups, each group is composed of 5 to 10 coil units, and the specific codes are D1-1, D1-2 … D1-10, D2-1, D2-2 … D2-10 … D8-10. Similarly, the code reading coils are divided into two groups, each group consists of 1 to 5 coil units and is coded as C1-1, C1-2 … C1-5, C2-1, C2-2 … C2-5.
When the absolute position sensor works normally, the positioning mark plate 7 generally passes through the left side or the right side of the U-shaped groove 2 of the code reader in a single direction, and a process of inserting from the middle does not exist generally. Therefore, the present invention only needs to arrange the on-off logic of the analog detection coil 71 for the code reading and positioning logic when the absolute position sensor normally works. The invention adopts a high-speed analog switch to realize the control of the on-off of the coil unit. The high-speed analog switch is controlled by a Field Programmable Gate Array (FPGA).
Each coil unit is logic 1 when turned on and logic 0 when turned off. When all the coil units of the D10 groups (D10-1, D10-2 … D10-10) are disconnected, the receiving voltage of U10 (voltage at two ends of the positioning coil 10) is maximum, the detection coil 71 is not shielded by the copper foil of the positioning mark plate 7, and the corresponding logic in D10 is 000000 and is represented as 0x000 by 16 system. Similarly, when the coil units of the D10 group are all closed, the voltage of the U10 is minimum, and further the detection coil 71 is completely shielded by the copper foil, the corresponding logic in the D10 is 1111111111, and the 16 system is represented as 0x3 FF. D10-1 is the lowest order and D10-10 is the highest order. The code of the positioning mark plate 7 simulated by the code reading coil is as follows: 0001. the specific turn-on logic is as follows:
simulating the position of the position indicator panel 7 at the time of position 1. The time when the index plate 7 reached position 1 is denoted as T1, and the time when the simulation detection started is denoted as T0. At T0, the corresponding logic value of each group of sub-coils is D10 ═ 1111111111D9 ═ 11111111111; d8 ═ 1111111111; d7 ═ 1111111111; c1 ═ 11111; c2 ═ 11111; d4 ═ 0000000000; d3 ═ 0000000000; d2 ═ 0000000000; d1 ═ 0000000000. All the receiving ends of the positioning coils of the absolute position sensor output logic 0 at the moment, namely U17＝U28＝U39＝U4100, the code reading coil outputs a logic 1, i.e., U651'. The switching condition of the sub-coils is expressed by using 16-system numerical values for convenience in description. The process from time T0 to time T1 can be expressed as the process shown in table 1, and the logic values of the positioning coils in each group change as follows: a10:0x 3FF-0x1F, a9: no change, A8: no change, a7: no change, a4:0x 00-0x1F, A3: no change, a2: no change, a1: there was no change. When T1 is reached, a10 is a4, and the voltage received by coil 10 is equal to the voltage received by coil 4, i.e., u is equal to u4-u10≈0，u410＜Vref410And the receiving end of the absolute position sensor outputs logic 1 to start reading codes. When C1 is 11111, C2 is 00000, the voltage of the code reading coil is:
thus reading the most significant bit of the code as "0".
Simulating the time of day state of the alignment mark plate 7 at position 2. When the position indicator plate 7 reaches the position 2, the time is denoted as T2, and when the position indicator plate reaches T2 from T1, the logical value of each sub-coil changes as follows: a10:0x 1F-0x00, A9:0x 3FF-0x1F, a8: no change, a7: no change, a4:0x 1F-0x3FF, A3:0x 00-0x1F, A2: no change, a1: no change, C1:0x1F, C2:0x 00. When the time T2 is reached, the output logic of the receiving end of the absolute position sensor is U410＝U39＝1，U17＝U28When the absolute position sensor starts reading code, the state of the code reading coil is changed, and C1 is 0x1F, and C2 is 0x 00. The read next highest bit is encoded as "0".
Simulating the position of the position indicator panel 7 at time 3. Will decideWhen the time point at which the bit flag 7 reaches the position 3 is recorded as T3 reaching T3 from T2, the logical value of each sub-coil group changes as follows: a10:0x00, A9:0x 1F-0x00, A8:0x 3FF-0x1F, a7: no change, a4:0x3FF, A3:0x 1F-0x3FF, a2:0x 00-0x1F, A1: no change, C1:0x1F, C2:0x 00. When the time T3 is reached, the output logic of the receiving end of the absolute position sensor is U410＝U39＝U28＝1，U17When the absolute position sensor starts reading code, the state of the code reading coil is changed, and C1 is 0x1F, and C2 is 0x 00. The read next lowest code is "0".
Simulating the position of the position indicator panel 7 at time 4. When the time at which the index plate 7 reaches the position 4 is expressed as T4 reaching T4 from T3, the logical value of each sub-coil group changes as follows: a10:0x00, A9:0x00, A8:0x1F-0x00, A7:0x3FF-0x1F, A4:0x3FF, A3:0x3FF, A2:0x1F-0x3FF, A1:0x00-0x1F, C1:0x1F, C2:0x 00. When the time T4 is reached, the output logic of the receiving end of the absolute position sensor is U410＝U39＝U28＝U17When the absolute position sensor starts reading code at 1, the state of the code reading coil is changed, C1 is 0x00, and C2 is 0x 1F. The read low encoding is "1".
Simulating the state of the position indicator panel 7 when it leaves the absolute position sensor. The positioning mark plate 7 starts to move leftwards relative to the absolute position sensor from the position 4 until the coil 7 is not shielded by the copper foil, that is, the whole code reading process is completed, and this time is recorded as T5. The logic value of each sub-coil group from T4 to T5 changes as follows: a10:0x00, A9:0x00, A8:0x00, A7:0x1F-0x00, A4:0x3FF, A3:0x3FF, A2:0x3FF, A1:0x1F-0x3FF, C1:0x00, C2:0x 1F. At this time, the logic output values of the positioning coil and the code reading coil at the receiving end of the absolute position sensor are as follows: u shape410＝U39＝U28＝U17＝1,U65＝1。
TABLE 1 switch logic table
The above process simulates the code reading of the position indicator plate 7 by the absolute position sensor in one cycle (one cycle from the time the position indicator plate 7 enters the absolute position sensor to the time the position indicator plate leaves the absolute position sensor), and the next code reading process is started at T0, and all the detection coil 71 logic values are initialized. Different encoding of the marker panel 7 is simulated by changing the values of C1 and C2 at the reading time T1, T2, T3 and T4. The coding logic table is shown in table 2 below.
TABLE 2 code-reading logic table
The invention can simulate the speed of the maglev train passing through the absolute position sensor by controlling the time in each code reading process, thereby detecting the performance of reading the absolute position code of the absolute position sensor at different speeds. As shown in table 1, the time interval t represents the speed at which the index plate 7 passes through the absolute position sensor. The time interval is controlled by the timing function of the FPGA. The on/off of each coil unit in the detection coil 71 is controlled by an analog switch 74HCT 4066. As shown in fig. 6, the analog switch controls the input of high frequency signals 1E, 2E, 3E, and 4E to turn on the corresponding coils. Otherwise, the input low-level coil is disconnected. The maximum conducting current of the analog switch is +/-25 mA, and the switching time is 16 ns. Taking the train running at 200km/h as an example, the length of the positioning mark plate 7 is 300mm, and 5.4ms is needed for completing one code reading at the speed. According to the above-mentioned analog system code reading logic sequence, 25t is required for completing one code reading, so that the switching time t of each analog switch is 0.216 ms.
As a further preferred embodiment, the present invention further includes a signal acquisition card connected to the detection coil controller 8, and the accuracy of reading the absolute position sensor at different speeds can be rapidly obtained by collecting the positioning code sent by the absolute position sensor through the signal acquisition card and comparing the positioning code with the data of the analog positioning mark plate 7 applied by the detection coil controller 8.
The invention can also simulate and detect the working condition of the positioning mark plate 7 passing through the U-shaped groove 2 of the code reader under different posture conditions. As shown in fig. 7, the positioning mark plates 7 respectively pass through the U-shaped slot 2 of the code reader under different heights, and the area of the coil unit group in the absolute position sensor, which is shielded by the copper foil, changes with the height. According to the working principle of the detection coil 71, the opening number of the coil units in the detection coil 71 can simulate the area of the coil unit group shielded by the copper foil. Therefore, the number of the opened coil groups can be adjusted by simulating the code reading working conditions at different heights.
For example, at a position 30mm away from the absolute position sensor of the positioning marker plate 7 shown in fig. 7, 6 coil units are turned on to simulate a previous time T0 before code reading, that is, a10 ═ 0x3F, a9 ═ 0x3F, a8 ═ 0x3F, a7 ═ 0x3F, C1 ═ 0x7, C2 ═ 0x7, a4 ═ 0x00, A3 ═ 0x00, a2 ═ 0x00, and a1 ═ 0x 00. At time T1, the logical value of each sub-coil group is: a10 ═ 0x07, a9 ═ 0x3F, A8 ═ 0x3F, a7 ═ 0x3F, C1 ═ 0x07, C2 ═ 0x00, a4 ═ 0x07, A3 ═ 0x00, a2 ═ 0x00, and a1 ═ 0x 00. As shown in fig. 8, for the positioning coil, it can be approximately set that the analog sensor is positioned by 8% of the copper foil when one coil unit is opened, and the analog code reading coil is shielded by 18% of the copper foil when one coil unit is opened. Therefore, the code reading performance of the sensor at different heights can be detected.
By simulating the reading of the sensor at different speeds and heights, the PC is used for receiving the reading information of the sensor and comparing the reading information with the simulated reading information, and the current state of the sensor, whether a fault exists and fault information are displayed.
On the other hand, as shown in fig. 9, the present invention further provides a performance detection method for an absolute position sensor of a maglev train, which is based on the performance detection device for an absolute position sensor of a maglev train for detection, and the detection method includes the following steps:
step one, a positioning mark plate 7 is placed to a preset initial position by adjusting a detection coil adjusting support;
secondly, the observation computer 9 sends a control instruction to the detection coil 71 through the detection coil controller 8, the on-off of the sub-coil in the detection coil 71 is changed through the high-speed analog switch, and then the received signal of the receiving coil is changed, so that the signal reading of the receiving coil is controlled, and the analog control of the code reading value of the absolute position sensor is realized; specifically, the implementation of analog control of the read code value of the absolute position sensor in this step is embodied as: the control instruction is sent by the observation computer 9 to change the on-off speed of the coil, so that the code reading speed of the absolute position sensor is changed; the observation computer 9 sends a control instruction, the number of the on-off of the coils is adjusted through the high-speed analog switch, and the code reading performance of the sensor of the positioning mark plate 7 at different heights and different postures is further tested.
Step four, repeating the step one to the step three until the absolute position sensor finishes the code reading of the positioning mark plate in one period; it should be noted that, the step four is not limited to one time, and may be repeated for multiple times, so as to more accurately realize the evaluation of the performance and quality of the absolute position sensor;
and step five, the observation computer evaluates the performance and the quality of the absolute position sensor according to the obtained code reading result.
In summary, the detection coil 71 in the invention is composed of a series of sub-coils, and the observation computer 9 sends a control command through the detection coil controller 8 to change the on-off of each sub-coil; the detection coil 71 is arranged between the transmitting coil and the receiving coil of the absolute position sensor, and the change of the actual on-off state of the detection coil 71 can cause the change of the receiving signal of the receiving coil, thereby controlling the signal reading of the receiving coil and realizing the analog control of the code reading value of the sensor. Meanwhile, the code reading speed of the absolute position sensor can be changed by changing the on-off speed of the detection coil 71; the number of the on-off of the detection coils 71 is adjusted to test the code reading performance of the absolute position sensor of the positioning mark plate 7 at different heights and different postures. The observation computer 9 processes the position and speed signals sent back by the simulator to evaluate the performance and quality of the absolute position sensor. Through the process, the running condition of the absolute position sensor can be simulated simply and conveniently at various speeds, the performance evaluation of the absolute position sensor is realized, and the detection efficiency of the absolute position sensor can be effectively improved.
In the description above, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore should not be construed as limiting the scope of the present invention.
In conclusion, although the present invention has been described with reference to the preferred embodiments, it should be noted that, although various changes and modifications may be made by those skilled in the art, they should be included in the scope of the present invention unless they depart from the scope of the present invention.
Claims (10)
1. The absolute position sensor performance detection device of the magnetic-levitation train is characterized by comprising a positioning mark plate, a code reader U-shaped groove, a detection coil controller, a detection coil mounting bracket, a detection coil adjusting bracket, a simulator and an observation computer, wherein the detection coil adjusting bracket is slidably arranged on the detection coil mounting bracket, the code reader U-shaped groove is arranged below the detection coil mounting bracket, the positioning mark plate is arranged at the lower end of the detection coil adjusting bracket and can transversely, vertically and longitudinally move in the code reader U-shaped groove through the detection coil adjusting bracket, the positioning mark plate comprises a detection coil and a printed circuit board, the detection coil consists of a plurality of groups of sub-coils and is arranged between a transmitting coil and a receiving coil of the absolute position sensor, and the plurality of groups of sub-coils are arranged on the front surface and the back surface of the printed circuit board according to certain interval size, the detection coil is connected with an observation computer through a detection coil controller, the detection coil controller is connected with each group of sub-coils in the detection coil through a high-speed analog switch, and the simulator is respectively connected with the positioning mark plate and the observation computer.
2. The absolute position sensor performance detection device of a magnetic-levitation train as recited in claim 1, wherein the plurality of sets of said sub-coils are divided into a plurality of sets of positioning coils and a plurality of sets of code reading coils, each set of positioning coils and each set of code reading coils are composed of a plurality of coil units, and each coil unit is switched on and off by a high-speed analog switch.
3. The absolute position sensor performance detecting device of a maglev train according to claim 1, wherein the detecting coil adjusting bracket comprises at least a slider, a vertical screw and two guide rails, wherein the two guide rails are fixed on the detecting coil mounting bracket in parallel and at intervals in the transverse direction, the slider is arranged in the longitudinal direction and can slide on the two guide rails, the vertical screw passes through the slider in the vertical direction and can move on the slider in the longitudinal direction and the vertical direction, and the positioning mark plate is fixed at the lower end of the vertical screw.
4. The absolute position sensor performance detection device of a magnetic-levitation train as recited in claim 3, wherein the detection coil adjusting bracket further comprises a first driving mechanism, the first driving mechanism is respectively connected with the slider and the observation computer; and/or the detection coil adjusting bracket further comprises a second driving mechanism, and the second driving mechanism is respectively connected with the vertical screw and the observation computer; and/or the detection coil adjusting support further comprises a third driving mechanism, and the third driving mechanism is respectively connected with the vertical screw and the observation computer.
5. The absolute position sensor performance detection device of a maglev train of claim 3, wherein the detection coil mounting bracket is a three-dimensional frame structure, the U-shaped groove of the code reader is transversely fixed at the bottom of the three-dimensional frame structure, and the two guide rails are fixed at the top of the three-dimensional frame structure.
6. The absolute position sensor performance detection device of a maglev train of any one of claims 1 to 5, wherein the high-speed analog switch is controlled by a programmable logic device (FPGA), and is embodied as: and the programmable logic device FPGA inputs high electric frequency to the high-speed analog switch to conduct the corresponding sub-coil, and the programmable logic device FPGA inputs low level to the high-speed analog switch to disconnect the corresponding sub-coil.
7. The absolute position sensor performance detection device of a maglev train according to claim 6, wherein the detection coil controller simulates the area of the transmitting coil and the receiving coil shielded by the copper foil when the positioning mark plate passes through the absolute position sensor through the number of the sub-coils in the detection coil communicated with the high-speed analog switch.
8. The apparatus of claim 1, wherein the absolute position sensor is capable of reading absolute position codes at different speeds by controlling the time of each code reading process to simulate the speed of the maglev train passing through the absolute position sensor.
9. A method for detecting the performance of an absolute position sensor of a maglev train, which is characterized in that the detection is carried out based on the device for detecting the performance of the absolute position sensor of the maglev train of any one of claims 1 to 8, and the detection method comprises the following steps:
the method comprises the following steps that firstly, a detection coil is adjusted to adjust a support to place a positioning mark plate to a preset initial position;
secondly, the observation computer sends a control instruction to the detection coil through the detection coil controller, and the on-off of the sub-coil in the detection coil is changed through the high-speed analog switch, so that the received signal of the receiving coil is changed, the signal reading of the receiving coil is controlled, and the analog control of the code reading value of the absolute position sensor is realized;
thirdly, the observation computer receives and processes the positioning mark plate code reading speed signal and the position signal which are transmitted back by the simulator;
step four, repeating the step one to the step three until the absolute position sensor finishes the code reading of the positioning mark plate in one period;
and step five, the observation computer evaluates the performance and the quality of the absolute position sensor according to the obtained code reading result.
10. The method for detecting the absolute position sensor performance of the magnetic-levitation train as recited in claim 9, wherein the step two of implementing the analog control of the read code value of the absolute position sensor is embodied as: the on-off speed of the coil is changed by sending a control instruction through the observation computer, so that the code reading speed of the absolute position sensor is changed; the control instruction is sent by the observation computer, the on-off quantity of the coils is adjusted by the high-speed analog switch, and the code reading performance of the sensor of the positioning mark plate under different heights and different postures is tested.
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