Railway signal relay contact pressure multichannel measurement method based on visual positioning

Abstract

The invention discloses a railway signal relay contact pressure multi-channel measurement method based on visual positioning, and the method comprises the steps: driving a plurality of cantilever beam contact pressure sensors which are installed in a manner of directly facing a contact group of a railway signal relay to move towards the contact group which is stably attracted; under the feedback of the visual positioning system, the first static contact is driven to be in contact with the preset position of the first static contact of each contact group; and driving all the cantilever beam contact pressure sensors to separate the movable contacts and the first static contacts of the contact groups, and detecting first deformation values of the cantilever beam contact pressure sensors during separation so as to derive first contact pressure of each contact group. According to the invention, the distance between the contact pressure sensor and the moving contact and the static contact in the product to be measured can be controlled more accurately by applying the visual positioning technology, the front end of the contact pressure sensor is ensured to be in accurate contact with the position to be measured in the relay, and the accuracy of the measurement result is ensured.

Description

Technical Field

[0001] This invention relates to a detection technology for the mechanical characteristic parameters of railway signal relays, specifically a multi-channel measurement method for the contact pressure of railway signal relays based on visual positioning. Background Technology

[0002] In railway systems, railway signal relays are crucial components ensuring the safe and stable operation of the railway system. They possess numerous functions, including switching circuits, automatic control, and remote control. Railway relays typically employ electromagnetic control and mainly consist of two parts: an electromagnetic mechanism and a contact system. The contact system comprises multiple contact groups, each including a moving contact, a first stationary contact located on one side of the moving contact (e.g., the upper side), and a second stationary contact located on the other side of the moving contact (e.g., the lower side). Their working principle involves controlling the excitation and demagnetization of the electromagnetic coil to drive the armature and moving parts, thereby changing the on / off state of the contact system. In circuits requiring fail-safe functionality, electromagnetic gravity-type or electromagnetic spring-gravity-type relay structures are generally used.

[0003] The performance parameters of electromagnetic railway signal relays mainly include mechanical and electrical characteristics. Factory testing of these key parameters is crucial. Currently, the testing of the mechanical characteristics of railway signal relay contact pressure in China is still largely done manually. This method is highly susceptible to subjective human factors, has low efficiency, and lacks standardized test results, failing to meet the reliability testing and evaluation requirements of the existing railway system. The contact pressure of the railway signal relay's contact system is a vital mechanical characteristic parameter for factory testing of railway relays. Figure 2 When the relay is in the released state, the contact cylinder of the moving contact piece contacts the silver contact at the front end of the first stationary contact or the second stationary contact. The contact pressure is the magnitude of the external force required to separate the contact cylinder of the moving contact from the silver contact at the front end of the first stationary contact or the second stationary contact. Summary of the Invention

[0004] Currently, the testing of the mechanical characteristics of railway signal relay contact pressure in China is still limited to manual inspection. This method is highly susceptible to subjective human factors, has low efficiency, and lacks standardized test results, failing to meet the reliability testing and evaluation requirements of existing railway systems. This invention proposes a vision-based multi-channel measurement method for railway signal relay contact pressure that effectively solves the above problems.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] This invention provides a multi-channel measurement method for railway signal relay contact pressure based on visual positioning, comprising the following steps:

[0007] Step 1: Fix the railway signal relay in place such that all the multiple contact groups of the railway signal relay are oriented toward the first side.

[0008] Step 2: Power on the railway signal relay so that the moving contact and the first stationary contact of each contact group are attracted together and reach a stable state;

[0009] Step 3: Drive the multiple cantilever beam contact pressure sensors, which are installed opposite to the contact group of the railway signal relay, to move toward the contact group that is stably engaged, and drive them into the first predetermined position between the moving contact and the first stationary contact of each contact group under the feedback of the visual positioning system.

[0010] Step 4: Drive the cantilever beam contact pressure sensor to separate the moving contact and the first stationary contact of the contact group, and detect the first deformation value of the cantilever beam contact pressure sensor at the time of separation to derive the first contact pressure of each contact group.

[0011] In some embodiments, the visual positioning system provides feedback by acquiring a first image of the relative position of each cantilever beam contact pressure sensor relative to its corresponding contact group from a second lateral direction orthogonal to the first lateral direction using an industrial camera, processing the first image to obtain pixel coordinates of the edges of the cantilever beam contact pressure sensor, the edges of the moving contact, and the edges of the first stationary contact, thereby generating and providing first feedback regarding the relative position of the cantilever beam contact pressure sensor with respect to the moving contact and the first stationary contact.

[0012] In some embodiments, the method further includes combining the calibration information of the industrial camera to calculate the actual distance corresponding to the difference in the actual pixel coordinates in the first image, thereby converting the tested pixel coordinates into a first actual distance, and forming the first feedback based on the first actual distance.

[0013] In some embodiments, the position of the cantilever beam contact pressure sensor is accurately controlled according to the first actual distance, so that the front end of the cantilever beam contact pressure sensor lifts the front end of the first static contact, thereby changing the railway signal relay from the engaged state to the disengaged state. The first contact pressure is derived from the deformation value of the cantilever beam contact pressure sensor when the engaged state and the disengaged state change.

[0014] Preferably, the visual positioning system providing the first feedback and the second feedback may further include using a light source to provide illumination so that the acquired image is clear, and the test area of ​​the railway signal relay is bright and highly reflective.

[0015] In some embodiments, a pair of industrial cameras are installed on a second side and a third side orthogonal to the first side of the railway signal relay, respectively, to obtain images of the contact group located on the second side and the contact group located on the third side, respectively.

[0016] In some embodiments, making the contact group of the relay under test attract and reach a stable state includes: turning on the power supply of the railway signal relay to energize the electromagnetic circuit of the railway signal relay, and the electromagnetic force generated by the electromagnetic coil pushes the moving contact bracket to move upward through the contact mechanical structure, thereby causing the moving contact of each contact group to reliably engage with the first stationary contact.

[0017] In some embodiments, each of the cantilever beam contact pressure sensors and its corresponding contact group are positioned on the same axis along the first lateral direction.

[0018] In some embodiments, for a railway signal relay comprising multiple contact groups, an independent motor controls the cantilever beam contact pressure sensor corresponding to each contact group to complete the measurement procedure of the first contact pressure of that contact group. When the measurement procedure of the first contact pressure of a certain contact group is completed, the cantilever beam contact pressure sensor is driven and exits the waiting position outside the railway signal relay.

[0019] In some embodiments, step 5 is further included: resetting all cantilever beam contact pressure sensors; de-energizing the railway signal relay so that the moving contact of each contact group stably contacts the second stationary contact after being stably released from the first stationary contact; adjusting the height of the plurality of cantilever beam contact pressure sensors and accurately driving them into a second predetermined position between the moving contact and the second stationary contact of each contact group under the feedback of the visual positioning system; driving the cantilever beam contact pressure sensors to press down on the second stationary contact of each contact group; detecting the second deformation value of the cantilever beam contact pressure sensors when the moving contact and the second stationary contact separate, thereby deriving the second contact pressure of each contact group.

[0020] In some embodiments, the visual positioning system provides feedback by using an industrial camera to acquire a second image from a second lateral direction orthogonal to the first lateral direction, showing the cantilever beam contact pressure sensor approaching the contact group of the railway signal relay; processing the second image to obtain pixel coordinates of the edge of the cantilever beam contact pressure sensor, the edge of the moving contact, and the edge of the second stationary contact; thereby generating and providing second feedback regarding the relative position of the cantilever beam contact pressure sensor with respect to the moving contact and the second stationary contact.

[0021] In some embodiments, the method further includes combining the calibration information of the industrial camera to calculate the actual distance corresponding to the difference in the actual pixel coordinates in the second image, thereby converting the tested pixel coordinates into a second actual distance, and forming the second feedback based on the second actual distance.

[0022] In some embodiments, the position of the cantilever beam contact pressure sensor is accurately controlled according to the second actual distance, so that the front end of the cantilever beam contact pressure sensor presses down on the front end of the second stationary contact, thereby changing the moving contact and the second stationary contact of the railway signal relay from the engaged state to the disengaged state. The second contact pressure is derived from the deformation value of the cantilever beam contact pressure sensor when the engaged state and the disengaged state change.

[0023] The present invention has the following beneficial effects and advantages:

[0024] 1. This invention is based on computer machine vision ranging technology and a specially designed contact pressure sensor to simultaneously measure the pressure of eight sets of contacts in a railway signal relay. The application of visual positioning technology can more accurately control the distance between the contact pressure sensor and the moving and stationary contacts in the product under test, ensuring accurate contact between the front end of the contact pressure sensor and the position to be measured in the relay, thus ensuring the accuracy of the measurement results.

[0025] 2. This invention uses an industrial control computer to detect the on / off signals of railway signal relays, offering higher sensitivity compared to manual detection. During measurement, eight sets of contacts of the railway signal relays are monitored simultaneously. When the electrical signal changes, the contact pressure sensor transmitter can accurately and quickly read the measured pressure value. The eight sets of cantilever beam contact pressure sensors are easy to integrate, can be used for independent detection, and can be quickly assembled and disassembled. Attached Figure Description

[0026] Figure 1 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0027] Figure 2 A flowchart illustrating the distinguishing steps of a railway signal relay contact pressure measurement method according to another embodiment of the present invention;

[0028] Figure 3 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0029] Figure 4 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0030] Figure 5 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0031] Figure 6 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0032] Figure 7 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0033] Figure 8 A flowchart of a railway signal relay contact pressure measurement method according to an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of the system upon which the railway signal relay contact pressure measurement method according to an embodiment of the present invention is based;

[0035] Figure 10 This is a schematic diagram of the structure of an image acquisition device according to an embodiment of the present invention;

[0036] Figure 11 This is a schematic diagram illustrating the contact pressure of a railway signal relay according to an embodiment of the present invention;

[0037] Figure 12 This is a schematic diagram of the contact pressure sensor probe positioning after image processing of a railway signal relay according to an embodiment of the present invention;

[0038] Figure 13 This is a schematic diagram of a multi-channel contact pressure integrated tooling for railway signal relays according to an embodiment of the present invention;

[0039] Figure 14 This is a schematic diagram of railway signal relay contact pressure measurement according to an embodiment of the present invention;

[0040] In the diagram: 1 is an industrial camera, 2 is a light source, 3 is a railway signal relay mounting base, 103 is a moving contact bracket, 104 is a moving contact, 105 is the first stationary contact, 106 is the second stationary contact, 6 is a cantilever beam contact pressure sensor mounting fixture, 7 is the cantilever beam contact pressure sensor, and 10 is a railway signal relay. A 20-bit host computer is also included. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the technical solutions and accompanying drawings.

[0042] like Figure 1 As shown, the visual positioning-based multi-channel measurement method for railway signal relay contact pressure of the present invention generally includes the following steps:

[0043] Step 1: Fix the railway signal relay 10, also known as the relay under test, so that the multiple contact groups of the railway signal relay are all oriented towards the first side.

[0044] Step 2: Power on the railway signal relay 10 so that the moving contact 104 and the first stationary contact 105 of each contact group are attracted and reach a stable state;

[0045] Step 3: Drive the multiple cantilever beam contact pressure sensors 7, which are installed opposite to the contacts of the railway signal relay 10 along the X direction, to move toward the contact group that is stably engaged, and drive them to contact the predetermined position of the first static contact 105 under the feedback of the visual positioning system.

[0046] Step 4: Drive the cantilever beam contact pressure sensor to raise the first stationary contact of each contact group, and detect the first deformation value of the cantilever beam contact pressure sensor when the moving contact and the first stationary contact are separated to derive the first contact pressure of each contact group.

[0047] In some embodiments, step 5 is further included: resetting all cantilever beam contact pressure sensors; de-energizing the railway signal relay so that the moving contact of each contact group stably contacts the second stationary contact after being stably released from the first stationary contact; adjusting the height of the plurality of cantilever beam contact pressure sensors and accurately driving them into a second predetermined position between the moving contact and the second stationary contact of each contact group under the feedback of the visual positioning system; driving the cantilever beam contact pressure sensors to press down on the second stationary contact of each contact group; detecting the second deformation value of the cantilever beam contact pressure sensors when the moving contact and the second stationary contact separate, thereby deriving the second contact pressure of each contact group.

[0048] In practical implementation, the above method may incorporate steps such as equipment installation, calibration, and standardization as needed. Thus, the vision-based multi-channel measurement method for railway signal relay contact pressure in some embodiments of this invention, such as... Figure 2 As shown, the following steps may be included after step 1:

[0049] Step 1a: Install image acquisition devices on both sides of the railway signal relay 10, such as an industrial camera 1 set at a predetermined position and a light source 2 corresponding to the industrial camera 1. The calibration and standardization of the industrial camera 1 can be completed immediately after the industrial camera 1 is installed.

[0050] Step 1b: A cantilever beam contact pressure sensor fixing fixture 6 is installed in front of the railway signal relay 10 in the X direction. The fixture 6 is equipped with cantilever beam contact pressure sensors 7 corresponding to the number of contact groups on the railway signal relay 10. Each cantilever beam contact pressure sensor 7 is on the same axis as its corresponding contact group on the railway signal relay 10. It should be understood that eight groups of cantilever beam contact pressure sensors 7 are used here to match the number of contact groups on the railway signal relay. In other embodiments, if the number of contact groups on the railway signal relay is different, such as six or ten groups, the contact pressure sensors will be adjusted accordingly. All cantilever beam contact pressure sensors 7 can be mounted on the cantilever beam contact pressure sensor fixing fixture 6. For example, the cantilever beam contact pressure sensor fixing fixture 6 provides an array of mounting slots to fix the fixed end of the cantilever beam contact pressure sensor. Each mounting slot can provide a motor drive for each cantilever beam contact pressure sensor 7, allowing the cantilever beam contact pressure sensor 7 to move independently towards or away from the railway signal relay 10. The multiple slots of the cantilever beam contact pressure sensor fixing fixture 6 can be driven as a whole by a motion mechanism, allowing all cantilever beam contact pressure sensors 7 to move in three degrees of freedom: up and down, forward and backward, and left and right.

[0051] Step 1c: Turn on the light source to provide illumination so that the acquired image is clearer. The edge of the cantilever beam contact pressure sensor 7 and the edge of the moving contact 104, the first stationary contact 105 and the second stationary contact 106 in the contact group are bright and reflective.

[0052] Next, we will continue with steps 2, 3, and 4 above to test the first contact pressure of the first static contact 105.

[0053] In step 2 above, the process can specifically include energizing the contact group of the relay under test and bringing it to a stable state. This can specifically include: turning on the power supply to the railway signal relay base, energizing the electromagnetic circuit of the railway signal relay, and causing the electromagnetic force generated by the electromagnetic coil of the railway signal relay fixed base 3 to drive the moving contact bracket 103 upward through the contact mechanical structure, so that the moving contact 104 of the railway signal relay reliably engages with the first stationary contact 105, i.e., the upper stationary contact piece; when the railway signal relay reaches a stable state during the engagement process, for example, by clicking the mouse to control the software of the host computer 20 to activate the image acquisition device, such as the internal trigger signal of the industrial camera 1, to capture an image of the area to be tested, including the moving contact 104, the first stationary contact 105, the second stationary contact 106, and the cantilever beam contact pressure sensor 7, in the engaged state. In this step, the area to be tested is the area where the moving contact 104 and the first stationary contact 105 are located in the stable state of the pull-in, as well as the area where the free end 71 of the cantilever beam contact pressure sensor 7 is located, especially the end profile of the moving contact 104 and the end profile of the second stationary contact 106, and the area where the free end 71 of the cantilever beam contact pressure sensor 7 is located.

[0054] In step 3, as Figure 3 As shown, it can specifically include:

[0055] Step 301: Perform preprocessing on the image of the stable attraction state captured by the industrial camera;

[0056] Step 302: Use template matching to identify the area to be tested and calculate the pixel coordinate information of the first static contact and the vertex of the free end 71 of the cantilever beam contact pressure sensor, such as... Figure 3 As shown;

[0057] Step 303: Calculate the distance between the silver contact 5 of the first stationary contact and the cantilever beam contact pressure sensor 7 based on the coordinate information. Based on the distance calculation result, control the free end 71 of the cantilever beam contact pressure sensor 7 to contact the predetermined position of the first stationary contact of the railway signal relay to facilitate lifting the first stationary contact.

[0058] Step 304: Drive the free ends 71 ​​of all cantilever beam contact pressure sensors 7 to separate the moving contact and the second stationary contact and measure the deformation value of the cantilever beam contact pressure sensor 7, thereby deriving the pressure of the second contact.

[0059] like Figure 4 As shown, step 303 may further include:

[0060] Step 3031: Combine the calibration information of the industrial camera to calculate the actual distance corresponding to the actual pixel coordinate difference, and convert the pixel coordinate information obtained by the test into the first actual distance.

[0061] Step 3032: After calculating the first actual distance, accurately control the position of the free end 71 of the cantilever beam contact pressure sensor 7 so that the free end 71 of the contact pressure sensor 7 contacts the predetermined position silver contact of the first stationary contact of the railway signal relay, thereby raising the first stationary contact.

[0062] like Figure 5 As shown, step 304 involves driving the free ends 71 ​​of all cantilever beam contact pressure sensors 7 to separate the moving contact and the second stationary contact, and measuring the deformation value of the cantilever beam contact pressure sensors 7 to deduce the pressure at the second contact. Specifically, this may include:

[0063] Step 3041: Drive the free end 71 of the end cantilever beam contact pressure sensor 7 to lift the first stationary contact to separate the moving contact and the first stationary contact, thereby changing the contact state of the contact group of the railway signal relay to the open state.

[0064] Step 3042, for example, when the industrial control computer detects a change in the electrical signal, it reads the deformation value sensed by the cantilever beam contact pressure sensor at that moment;

[0065] In step 3043, the industrial control computer converts the deformation value into the contact pressure value of the engaging state, that is, the value of the first contact pressure.

[0066] In the contact pressure test process of the railway signal relay, after obtaining the on / off signal when measuring the pressure of a certain contact group, the independent motor controls the cantilever beam contact pressure sensor 7 corresponding to that contact group to retreat to the waiting position outside the railway signal relay. After all eight contact pressures have been tested, the cantilever beam contact pressure sensor fixing fixture 6 drives all cantilever beam contact pressure sensors to reset.

[0067] To ensure measurement accuracy, the silver contact at the end of the first stationary contact of the railway signal relay and the free end of the cantilever beam contact pressure sensor 7 that contacts the silver contact of the first stationary contact can be located and identified. Specifically, image recognition can employ template matching technology to crop the area to be identified in the original image, setting the area outside the region to pure black. Before feature extraction, grayscale and binarization processing can be performed to highlight the reflective areas generated by the parallel light illuminating the front end of the first stationary contact and the free end 71 of the cantilever beam contact pressure sensor 7 in the side view, which serve as the feature extraction area. Distance calculations are performed on these two features, and the free end 71 of each cantilever beam contact pressure sensor is precisely controlled by the program to contact the edge of the end of the first stationary contact, thus completing the subsequent railway signal relay contact pressure test. During testing, the computer controls the motion axis of the cantilever beam contact pressure sensor fixing fixture 6 to simultaneously detect the contact pressure of the railway signal relay contact group. When the moving contact and the first stationary contact of a certain contact group disconnect, the computer successfully receives the electrical signal, and the contact pressure sensor moves along the contact axis as shown in the figure. Figure 6 Exit in the X direction as shown until the pressure test of all eight sets of railway signal relay contacts is completed.

[0068] In some embodiments, specifically, the railway signal relay is in the contact pressure test position, so that the relay coil is energized and the armature is attracted. The X-direction motion module and the Z-direction motion module drive the contact pressure sensor to a predetermined position. The industrial camera 1 takes pictures, identifies and measures the distance from the free end 71 of each cantilever beam contact pressure sensor to the corresponding first stationary contact. The system calculates the distance difference and drives the adjustment slide of the cantilever beam contact pressure sensor to compensate, so that the distance from the free end 71 of all cantilever beam contact pressure sensors to the corresponding first stationary contact is equal. Then, the X-direction motion module moves the cantilever beam contact pressure sensor 7 to the measurement position, and the Z-direction motion module moves the sensor upward. At the moment when the connection between the first stationary contact and the moving contact of each contact group is broken, the deformation value of the corresponding cantilever beam contact pressure sensor 7 is read until all eight sets of contact pressure data are acquired, and then the system returns to the predetermined position along the X direction.

[0069] As a usable cantilever beam contact pressure sensor, a simple cantilever beam design can be adopted. One end of the cantilever beam is a fixed end, fixed to the cantilever beam contact pressure sensor fixing fixture 6, and the other end is a free end 71 used to disconnect the connection between the first stationary contact and the moving contact of the contact group. This free end 71 can adopt a configuration such as a thin sheet or a needle shape to facilitate accurate disconnection of the connection between the first stationary contact and the moving contact.

[0070] Each cantilever beam contact pressure sensor 7 in the cantilever beam contact pressure sensor fixing fixture 6 is equipped with an independent motion mechanism and a stepper motor. When the pressure detection of a certain contact group is completed, the computer receives the detection completion electrical signal, and the stepper motor can individually control the cantilever beam pressure sensor corresponding to that contact group to exit the relay test area. It waits in the X-direction motion module until all eight groups of cantilever beam contact pressure tests are completed. After all contact pressure results are measured, the X-direction motion control module uniformly exits to the initial waiting position, thus completing this contact pressure test.

[0071] As described above, after detecting the contact pressure value during the above-mentioned engagement process, step 5 can be executed to continue obtaining the contact pressure value during the release process, that is, the second contact pressure between the moving contact and the second stationary contact when the relay contact group is in the released state.

[0072] In some embodiments, such as Figure 6 As shown, step 5 can specifically include:

[0073] Step 501: Turn off the power to the railway signal relay mounting base 3 to release each contact group of the railway signal relay under test and reach a stable state. Use the software control system of the host computer 20 to perform a contact pressure test of the railway signal relay.

[0074] Step 502: Take a picture of the area to be tested using an industrial camera 1, and process the image of the area to be tested obtained by the industrial camera 1 to generate an identification of the position of the free end 71 of the cantilever beam contact pressure sensor relative to the moving contact and the second stationary contact, thereby generating a feedback signal to drive the free end 71 of the cantilever beam contact pressure sensor to contact the predetermined position of the second stationary contact of the railway signal relay; the area to be tested in this process is the area where the moving contact and the second stationary contact are in a stable released state, and the free end 71 of the cantilever beam contact pressure sensor is located, especially the end contour of the moving contact and the end contour of the second stationary contact, and the area where the end contour of the free end 71 of the cantilever beam contact pressure sensor is located.

[0075] Step 503: Drive the free end 71 of the cantilever beam contact pressure sensor 7 to press down on the second stationary contact to separate the moving contact and the second stationary contact; measure the deformation value of the cantilever beam contact pressure sensor 7 to deduce the pressure of the second contact.

[0076] In step 501, releasing the contact group of the relay under test and reaching a stable state can be specifically achieved by: disconnecting the power supply to the base of the railway relay contact, de-energizing the electromagnetic circuit of the railway relay, and causing the electromagnetic coil to move downwards by gravity, so that the moving contact 104 of each contact group of the railway signal relay can reliably release from the first stationary contact and engage with the second stationary contact; when the railway signal relay reaches a stable state during the release process, the software of the host computer 20 is controlled by clicking the mouse to start image acquisition of the image acquisition section, and the second stationary contact of the railway signal relay and the contact pressure sensor are photographed to obtain sample images.

[0077] like Figure 7 As shown, step 502 can specifically include:

[0078] Step 5021: Combine the calibration information of the industrial camera to calculate the actual distance corresponding to the actual pixel coordinate difference of the area where the end contour of the moving contact and the end contour of the second static contact in the image are located, as well as the end contour of the free end 71 of the cantilever beam contact pressure sensor. The pixel coordinates obtained by the test are converted into the second actual distance.

[0079] Step 5022: After calculating the second actual distance, the second feedback is formed based on the second actual distance. Based on the second feedback, the position of each cantilever beam contact pressure sensor 7 is accurately controlled, and the cantilever beam contact pressure sensor fixing fixture 6 and the motor of each cantilever beam contact pressure sensor are driven so that the free end 71 of the cantilever beam contact pressure sensor 7 contacts the silver contact of the second stationary contact of the railway signal relay, thereby allowing the free end 71 to press down on the second stationary contact.

[0080] Two industrial cameras can be used to photograph both sides of the railway signal relay under test to identify features, thereby determining the positional relationship between the moving contact and the second stationary contact in the relay's contact group, as well as the free end 71 of the cantilever beam contact pressure sensor, thus determining the correct motion control trajectory. For example, two industrial cameras 1 and 2 can be used. Figure 6 The X-direction is orthogonally set to obtain images from both sides of the railway signal relay.

[0081] like Figure 8 As shown, step 503, driving the free end 71 of the cantilever beam contact pressure sensor 7 to separate the moving contact and the second stationary contact, measuring the deformation value of the cantilever beam contact pressure sensor 7, and thereby deriving the pressure of the second contact, can specifically include:

[0082] Step 5031: Drive the free end 71 of the end cantilever beam contact pressure sensor 7 to press down the silver contact of the second stationary contact, thereby separating the moving contact and the second stationary contact so that the contact state of the railway signal relay contact group changes to the open state.

[0083] Step 5032: When the industrial control computer detects a change in the electrical signal, it reads the deformation value sensed by the cantilever beam contact pressure sensor at that moment.

[0084] In step 5033, the industrial control computer converts the deformation value into the contact pressure value of the released state, that is, the value of the second contact pressure.

[0085] The contact pressure of railway signal relays is divided into an engaged state and a released state. Therefore, the process includes measuring the contact pressure in both the engaged and released states. However, the image processing and motion testing procedures are consistent regardless of whether the engagement or release is stable.

[0086] Figure 9 , Figure 10 , Figure 11 , Figure 13 , Figure 14 This refers to the schematic or structural diagram of the system in use. Figure 12 This is an image of the test area of ​​a railway signal relay when it reaches a stable state after being engaged. (Example:) Figures 9 to 14 As shown, an industrial camera 1 is used to acquire images of the first stationary contact of the relay under test and the free end 71 of the cantilever beam contact pressure sensor 7. A 24V rated voltage is supplied to the electromagnetic coil of the railway signal relay, causing the moving contact support 103 of the railway signal relay to move upwards under the action of electromagnetic force and reach a stable state. At this time, the moving contact 104 and the first stationary contact 105 are completely closed. The industrial camera 1 is used to acquire images of the silver contact of the first stationary contact and the free end 71 of the cantilever beam contact pressure sensor 7 when the contact is in a stable state. During the release process, the electromagnetic coil of the railway signal relay is de-energized, the electromagnetic force disappears, and the entire moving contact support 103 moves downwards under the action of the armature's gravity. The moving contact 104 contacts the second stationary contact 106. After the moving contact 104 and the second stationary contact 106 are in complete and reliable contact and the entire contact mechanism reaches a stable state, the industrial camera 1 is used to acquire images of the silver contact of the second stationary contact and the free end 71 of the cantilever beam contact pressure sensor 7 when the contact mechanism reaches a stable state during the release process.

[0087] Using computer machine vision image ranging technology, pixel-by-pixel ranging is performed on the images captured by industrial camera 1. Taking the attraction process as an example, the contour detection of the silver contact of the first stationary contact 105 of the railway signal relay and the free end 71 of the cantilever beam contact pressure sensor 7 in the images captured by industrial camera 1 is required, and the actual distance between the two is calculated. According to the calculation results, the industrial control computer controls the motion axis to move the cantilever beam contact pressure sensor 7 to the designated test position and starts the railway signal relay contact pressure test. When the computer detects that the railway signal relay contact electrical signal is disconnected, it reads the pressure value measured by the cantilever beam contact pressure sensor 7. After the pressure test of each group of railway signal relay contacts is completed, the test positions are withdrawn respectively. After the pressure test of the eight groups of relay contacts is completed, the pressure values ​​of each group of railway signal relay contacts are uniformly output to the main interface of the software, thus completing the relay contact pressure test.

[0088] This invention is based on computer machine vision ranging technology and a specially designed contact pressure sensor to simultaneously measure the pressure of eight sets of contacts in a railway signal relay. The application of visual positioning technology can more accurately control the distance between the contact pressure sensor and the moving contact, the first stationary contact, and the second stationary contact of the product under test, ensuring accurate contact between the front end of the contact pressure sensor and the position to be measured in the relay, thus ensuring the accuracy of the measurement results.

[0089] This invention uses an industrial control computer to detect the on / off signals of railway signal relays, offering higher sensitivity compared to manual detection. During measurement, eight sets of contacts of the railway signal relay are monitored simultaneously. When the electrical signal changes, the contact pressure sensor transmitter can accurately and quickly read the measured pressure value. The eight sets of contact pressure sensors are easy to integrate, can be used for independent detection, and can be quickly assembled and disassembled.

Claims

1. A multi-channel measurement method for railway signal relay contact pressure based on visual positioning, characterized in that, include: Step 1: Fix the railway signal relay in place such that all the multiple contact groups of the railway signal relay are oriented toward the first side. Step 2: Power on the railway signal relay so that the moving contact and the first stationary contact of each contact group are attracted together and reach a stable state; Step 3: Drive the multiple cantilever beam contact pressure sensors, which are installed opposite to the contact group of the railway signal relay, to move toward the stably engaged contact group, and under the feedback of the visual positioning system, drive them to contact the predetermined position of the first static contact of each contact group. Step 4: Drive all the cantilever beam contact pressure sensors to separate the moving contact and the first stationary contact of the contact group, and detect the first deformation value of the cantilever beam contact pressure sensor at the time of separation to derive the first contact pressure of each contact group.

2. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 1, characterized in that, The visual positioning system provides feedback by using an industrial camera to acquire a first image of the relative position of each cantilever beam contact pressure sensor relative to its corresponding contact group from a second lateral direction orthogonal to the first lateral direction, processing the first image to obtain the pixel coordinates of the free end of the cantilever beam contact pressure sensor, the edge of the moving contact, and the edge of the first stationary contact, thereby generating and providing first feedback on the relative position of the cantilever beam contact pressure sensor with respect to the moving contact and the first stationary contact.

3. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 1, characterized in that, It also includes combining the calibration information of the industrial camera to calculate the actual distance corresponding to the difference in the actual pixel coordinates in the first image, thereby converting the pixel coordinates obtained by the test into a first actual distance, and forming the first feedback based on the first actual distance.

4. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 1, characterized in that, Based on the first actual distance, the position of the cantilever beam contact pressure sensor is accurately controlled, so that the front end of the cantilever beam contact pressure sensor is raised to lift the front end of the first static contact, thereby changing the railway signal relay from the engaged state to the disengaged state. The deformation value of the cantilever beam contact pressure sensor when the engaged state and the disengaged state change is detected, and the first contact pressure is derived from the deformation value.

5. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 4, characterized in that, The visual positioning system provides the first feedback by using a light source to provide illumination so that the acquired image is clear and the test area of ​​the railway signal relay is bright and highly reflective.

6. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 1, characterized in that, A pair of industrial cameras are installed on the second and third sides, respectively, which are orthogonal to the first side of the railway signal relay, so as to obtain images of the contact group located on the second side and the contact group located on the third side, respectively.

7. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 1, characterized in that, For railway signal relays that include multiple contact groups, an independent motor controls the cantilever beam contact pressure sensor corresponding to each contact group to complete the measurement program of the first contact pressure of that contact group. When the measurement program of the first contact pressure of a certain contact group is completed, the cantilever beam contact pressure sensor is driven and exits the waiting position outside the railway signal relay.

8. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 1, characterized in that, The process also includes step 5: resetting all cantilever beam contact pressure sensors; de-energizing the railway signal relay so that the moving contact of each contact group stably contacts the second stationary contact after being stably released from the first stationary contact; adjusting the height of the plurality of cantilever beam contact pressure sensors and accurately driving them into a second predetermined position between the moving contact and the second stationary contact of each contact group under the feedback of the visual positioning system; driving the cantilever beam contact pressure sensors to press down on the second stationary contact of each contact group; detecting the second deformation value of the cantilever beam contact pressure sensors when the moving contact and the second stationary contact separate, thereby deriving the second contact pressure of each contact group.

9. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 8, characterized in that, The visual positioning system provides feedback by using an industrial camera to acquire a second image of the contact group of the cantilever beam contact pressure sensor approaching the railway signal relay from a second lateral direction orthogonal to the first lateral direction, processing the second image to obtain the pixel coordinates of the edge of the cantilever beam contact pressure sensor, the edge of the moving contact, and the edge of the second stationary contact, thereby generating and providing second feedback on the relative position of the cantilever beam contact pressure sensor with respect to the moving contact and the second stationary contact.

10. The method for multi-channel measurement of railway signal relay contact pressure based on visual positioning according to claim 8, characterized in that, It also includes combining the calibration information of the industrial camera to calculate the actual distance corresponding to the difference in the actual pixel coordinates in the second image, thereby converting the pixel coordinates obtained by the test into a second actual distance, and forming the second feedback based on the second actual distance; Based on the second feedback, the position of the cantilever beam contact pressure sensor is accurately controlled so that the front end of the cantilever beam contact pressure sensor presses down on the front end of the second stationary contact, thereby changing the moving contact and the second stationary contact of the railway signal relay from the engaged state to the disengaged state. The second contact pressure is derived from the deformation value of the cantilever beam contact pressure sensor when the engaged and disengaged states change.

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