An identity-based proctoring system to prevent cheating during exams

Abstract

This invention relates to the field of teaching management technology, specifically to an anti-cheating system based on big data monitoring. The system includes a video monitoring module and a wristband. The video monitoring module is evenly distributed around the sports field and is equipped with a Bluetooth communication module. The wristband includes a housing and a strap movably connected to the housing. The housing contains a data processing module that transmits signals to the Bluetooth communication module. The housing also contains a one-way tightening unit for the strap, which prevents cheating by proxy. A reset unit is also included to release the one-way tightening of the tightening unit. This reset unit transmits a stop-exam signal to the data processing module when the one-way tightening is released. By improving the timing method in middle- and long-distance running physical education exams, only a small number of invigilators are needed. The system uses video monitoring combined with automatic single-shot continuous timing to record exam scores, preventing cheating such as proxy testing.

Description

Technical Field

[0001] This invention relates to the field of teaching management technology, specifically to an identity-based invigilation and anti-cheating system. Background Technology

[0002] In middle- and long-distance running physical education tests, the test venue is relatively spacious and there are many candidates taking the test at the same time. Invigilators need to verify student information and record the candidates' middle- and long-distance running time. If invigilation is not in place, there is a risk of impersonation. Video surveillance is often used to verify whether candidates have impersonated others or cheated.

[0003] Meanwhile, when recording candidates' middle- and long-distance running times, invigilators often use a sequential timing method. That is, from the start of the test to the finish line, the invigilators only record the order and corresponding time on the timer. There is a possibility that the order in which candidates arrive can be reversed. For example, the fifth place finisher might have 3 minutes and 50 seconds, while the fifteenth place finisher might have 4 minutes and 20 seconds. Candidates report their personal information to the invigilators based on their ranking, and the invigilators enter the corresponding candidate's score information according to the ranking. In tests with a large number of candidates, invigilators cannot accurately identify each candidate. In other words, cheating methods such as collusion and changing rankings can still occur in the same test room and among the same batch of candidates.

[0004] Even though cheating methods such as colluding to change rankings among candidates in the same examination room can be prevented by having each candidate wear a number and checking the numbers one by one after the exam, in exams with a large number of candidates, invigilators cannot record a large amount of data and need to spend a lot of time after the exam to check the candidates' numbers and the order in which they arrived.

[0005] Institutions with limited sports education resources, such as universities or vocational colleges, face difficulties in quickly and accurately compiling and updating results. Furthermore, the aforementioned timed testing method requires all candidates to start simultaneously, necessitates continuous monitoring of the examination room by invigilators, and even relies solely on invigilators to manually determine scores, which carries the risk of favoritism and cheating, thus undermining the maintenance of a fair, just, and transparent examination environment. Summary of the Invention

[0006] The purpose of this invention is to improve the timing method in middle- and long-distance running physical education exams. With only a small number of invigilators, video surveillance combined with automatic single-time continuous timing is used to record the exam results, thereby enabling the identification of examinees, preventing cheating behaviors such as impersonation and proxy testing, and maintaining a fair, just, and open examination environment.

[0007] An identity-based exam monitoring and anti-cheating system includes video surveillance modules and wristbands. The video surveillance modules are evenly distributed around the sports field and each module incorporates a Bluetooth communication module. These modules are used to archive exam information and can utilize ordinary security cameras with Bluetooth communication modules to receive signals. Compared to other short-range wireless communication technologies, such as Wi-Fi (mobile hotspot) or NFC (Near Field Communication), Bluetooth offers significant comprehensive advantages in terms of transmission reliability, data security, device power consumption, and device cost in sports equipment. The large dataset generated by the video surveillance modules located within the stadium can be used not only for daily monitoring but also for verifying student scores.

[0008] The wristband includes a housing and a strap movably connected to the housing. The strap has a flexible toothed rack that moves freely with the strap. The housing contains a data processing module that works with a Bluetooth communication module. The housing also contains a tightening unit that works with the flexible toothed rack to tighten the strap in one direction. Furthermore, the housing contains a reset unit that works with the flexible toothed rack. The reset unit releases the unidirectional tightening of the strap by the tightening unit. When the tightening unit releases the unidirectional tightening, the reset unit transmits a stop signal to the data processing module.

[0009] The data processing module in the wristband is used to transmit signals to the video monitoring module. The data processing module is an electronic device that can transmit and receive Bluetooth signals, keep time, and store timing data. It can be equipped with a display screen or speaker to transmit signals to the wearer. When the video monitoring module receives the Bluetooth signal from the wristband, it only needs to take a picture of the current static image to determine the candidate's position in the physical education exam for subsequent record-keeping. Compared with dynamic video data, static images have obvious advantages in terms of convenience, whether forming paper documents or electronic archives. When receiving the Bluetooth signal from the wristband, the video monitoring module can also record the candidate's current position to determine whether the candidate has missed or missed any runs.

[0010] The tightening unit is used to prevent candidates from changing their wristbands to cheat on the exam. Once worn, it can only be tightened. Invigilators only need to verify the candidate and the corresponding wristband code. The candidate wears the wristband in front of them and it cannot be removed until the end of the exam. The reset unit is used to release the tightening unit at the end of the exam to remove the wristband from the candidate's hand. When the wristband is removed, the tightening unit sends a stop exam signal to the data processing module.

[0011] The tightening unit includes a gear shaft, at least one of which is rotatably mounted in the housing. Gear discs are symmetrically mounted at both ends of the gear shaft. The housing has mounting holes for the watch strap to enter and exit the housing. Flexible racks that mesh with the gear discs are located at least one end of each side of the watch strap along its length. A reversible ratchet is mounted on the gear shaft. The reversible ratchet includes a ratchet body and a reversing lever. A reversing lever for controlling the meshing direction is rotatably mounted on the ratchet body. An elastic element is installed between the reversing lever and the ratchet body, pressing the reversing lever to keep the ratchet body in a normally engaged state. The gear discs and the flexible racks on the watch strap mesh to form a gear and rack transmission mechanism. The reversible ratchet, in conjunction with the gear discs, forms a one-way locking mechanism, meaning the watch strap can only enter the housing through the mounting holes and cannot exit through them, thus preventing test-takers from changing wristbands to cheat on the exam.

[0012] The reset unit includes a reset hole penetrating the housing. A reset rod, which cooperates with a reversing lever, is slidably installed in the reset hole. The housing contains a jog switch that cooperates with the axial movement of the reset rod. The reset rod has a protrusion that triggers the jog switch and the reversing lever. The jog switch and the reversing lever are located on the same normal plane of the reset rod's movement axis. The end of the reversing lever away from the ratchet body is located in the space swept by the protrusion. The jog switch is electrically connected to the data processing module. The reset rod slides in along the axis of the reset hole until the protrusion contacts the reversing lever, thereby pressing the end of the reversing lever away from the ratchet body into the elastic element in a force-accumulating direction. At this time, the reversing lever unlocks the ratchet body, and the ratchet body is in a disengaged state, allowing the watch strap to detach freely from the housing. Simultaneously with the ratchet body unlocking, the protrusion contacts the jog switch, which transmits a start or stop exam signal to the data processing module, further preventing candidates from forcibly removing or replacing the wristband to cheat on the exam.

[0013] The tightening and resetting units can use an electromagnetic adsorption structure to fix the strap and the housing. To achieve the same locking force, a larger battery and a heavier electromagnet are required, which would significantly increase the size and weight of the bracelet, making it unsuitable for test takers to perform middle- and long-distance running tests.

[0014] The reset rod has a primary barb groove extending axially. The housing contains a primary spring latch that engages with the primary barb groove. The locking position of the primary spring latch and the primary barb groove is located at the point where the reversing rod is triggered by the reset rod. The reset rod also has a secondary barb groove extending axially. The housing contains a secondary spring latch that engages with the secondary barb groove. The locking position of the secondary spring latch and the secondary barb groove is located at the end point of the reset rod's depth. The point where the reversing rod is triggered by the reset rod and the end point of the reset rod's depth are staggered. The locking engagement of the primary spring latch and the primary barb groove allows the examinee to directly remove the reset rod at the end of the exam without continuously pressing it. The spring latch and barb groove at the end point of the depth prevent the examinee from accidentally triggering the reset rod while running or shaking it during the exam. This further enhances the examinee's autonomy during the exam, reduces reliance on invigilators, and improves the overall stability and practicality of the anti-cheating system.

[0015] The flexible toothed strip on the watch strap is recessed into the inner surface of the strap, with the tooth tips flush with the strap surface. This reduces wear on the flexible toothed strip, maintains its reliability, and minimizes the probability of sharp teeth contacting the wearer's skin, reducing discomfort. The flexible toothed strip has a metal tooth surface and its length is the same as the length of the case. The metal tooth surface further improves the reliability and wear resistance of the flexible toothed strip's engagement, extending its service life. The fact that the strap and case are aligned in the same length maximizes the use of the flexible toothed strip's length, thereby maximizing the strap's fit and suitability for wearers with different wrist sizes.

[0016] The watch band edge is provided with a metal connecting strip that conforms to the shape of the watch band and connects the toothed surfaces of the flexible toothed racks at both ends. The metal connecting strip is made of shape memory metal and is embedded in the watch band. The metal connecting strip can further improve the rigidity of the watch band, making it easier for the watch band to enter and exit the mounting holes. The shape memory metal can be made of nickel-titanium alloy or other materials such as copper-aluminum-nickel alloy. The housing is provided with elastic contacts that cooperate with the two flexible toothed racks. The two elastic contacts are electrically connected to the data processing module and are used to start and stop the data processing module. The metal connecting strip connects the two metal toothed surfaces into a conductor, which, together with the two elastic contacts, can form a circuit to realize the start and stop of the data processing module. The metal connecting strip embedded in the watch band can reduce the electrical interference of human skin and sweat to the above circuit, while improving the corrosion resistance of the metal connecting strip and improving the reliability of the anti-cheating system.

[0017] The reset rod has a frustum on one end of its body outside the watch band. The small end face of the frustum faces the housing. The wall of the reset hole has a chamfer that mates with the frustum. The chamfered surface has a flexible sheet. When the reset rod is at the end of the depth, the frustum and the chamfer are in contact. A sliding plate that mates with the frustum is slidably mounted on the inner wall of the housing. The sliding plate has a silicone pad on the side facing the watch band. The housing has an elastic element that pushes the sliding plate away from the watch band. When the reset rod is at the end of the depth, it pushes the sliding plate towards the watch band and through the silicone pad to seal the gap between the watch band and the mounting hole, further preventing sweat and impurities from entering the housing from the reset hole and affecting the operation of the meshing components.

[0018] The sliding plate has a locking tooth that engages with the watch strap on its side facing the strap. The locking tooth slides in the direction the watch strap enters the housing. An elastic element is provided between the locking tooth and the sliding plate. The displacement space of the locking tooth in the direction the watch strap enters the housing is one tooth pitch of the flexible toothed rack. When the sliding plate moves towards the watch strap side, sealing the gap between the watch strap and the mounting hole through the silicone pad, the movable locking tooth locks the flexible toothed rack on the watch strap, preventing the toothed rack from disengaging from the examinee due to excessive limb movement during the exam, thus preventing the watch strap from detaching from the examinee.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. Using video surveillance in conjunction with the wristband for automatic single-time timing to record middle and long-distance running physical education exam scores requires only a small number of invigilators to verify that the candidate and the corresponding wristband code match. The candidate wears the wristband in front of the invigilator, and the wristband is fixed in one direction by a ratchet and a toothed bar on the strap, ensuring that the candidate cannot remove it by themselves until the end of the exam. If the wristband is removed at any time, it will send a signal to stop the exam, thus binding the wristband to the candidate's identity during the exam. The timing score is automatically recorded without the need for manual recording by invigilators, preventing candidates from changing wristbands to cheat and preventing human error in recording.

[0021] 2. The gear and rack structure on the watch strap can achieve unidirectional fixation in conjunction with the ratchet, and can also serve as a stepless adjustment device for wrist size. The tightness of the housing 101 and the watch strap can be adjusted without the need for an additional watch strap adjustment device. This can maximize the matching and applicability of the watch strap for candidates with different wrist sizes, while reducing the weight of the entire bracelet component and reducing the discomfort caused by the bracelet structure to candidates, thereby preventing the bracelet from affecting their normal performance.

[0022] 3. The tapered fit formed by the reset rod and the wall of the reset hole on the wristband achieves a seal in the reset hole. The movement of the tapered surface drives the sliding plate, thereby achieving a seal between the wristband and the wristband housing. This prevents sweat and impurities from entering the housing through the reset hole and affecting the operation of the meshing components, further improving the operational stability and service life of the anti-cheating system. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a side view of the present invention;

[0025] Figure 3 for Figure 2 A schematic diagram of the AA section;

[0026] Figure 4 for Figure 3 Enlarged view of part D;

[0027] Figure 5 for Figure 2 BB cross-section diagram;

[0028] Figure 6 for Figure 5 Enlarged view of part F;

[0029] Figure 7 for Figure 5 Enlarged view of part E;

[0030] Figure 8 for Figure 2 CC section diagram;

[0031] Figure 9 This is a schematic diagram of the cross-section of the watch strap;

[0032] Figure 10 This diagram shows the position of the reset lever when the protrusion simultaneously contacts the jog switch and the reversing lever.

[0033] Figure 11 This is a schematic diagram showing the state of the reset rod at the end of the depth.

[0034] In the diagram: 1. Wristband; 101. Housing; 102. Data processing module; 103. Display screen; 104. Gear shaft; 105. Gear disc; 106. Mounting hole; 107. Reversible ratchet; 108. Ratchet body; 109. Reversing lever; 110. Elastic element one; 111. Reset hole; 112. Reset lever; 113. Jog switch; 114. Protrusion; 115. First-stage barb groove; 116. First-stage spring lock; 117. Elastic contact; 118. Frustum; 119. Slide plate; 120. Elastic element two; 121. Silicone pad; 122. Locking tooth; 123. Elastic element three; 124. Second-stage barb groove; 125. Second-stage spring lock; 2. Watch strap; 201. Flexible rack; 202. Metal connecting strip; 203. Toothed metal sheet. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0036] In the specific setup, video surveillance modules are evenly distributed around the sports field at 100-meter intervals at the junctions of straight sections and curves. 100 meters is the signal range of most Bluetooth devices, and the Bluetooth signals can operate without interference or overlap. The standard inner circle of the sports field is 400 meters, meaning four modules are deployed, numbered A, B, C, and D. Each video surveillance module is equipped with a Bluetooth communication module. The wristband 1's housing 101 is made of ABS hard resin, and the strap 2 is injection molded from TPU. The housing 101 contains a data processing module 102 that transmits signals to the Bluetooth communication module, and the housing 101 has a display screen 103 for displaying received signals. After students wear the wristband 1, they begin the middle-distance running physical education exam. When passing the video surveillance modules, the data processing module 102 on the wristband 1 communicates with the Bluetooth communication module, marking checkpoints. The Bluetooth communication module controls the corresponding video surveillance module to take photos for evidence. Simultaneously, the data on the wristband 1... The processing module 102 records the time. When the wristband 1 receives signals A, B, C, and D in sequence, it proves that the wearer of the wristband 1 has run one lap around the sports field. During this process, the data processing module 102 of the wristband 1 can act as a timer to record the time and communicate with the Bluetooth communication module. The wristband 1 records the time and automatically transmits the timing results of the middle and long distance running physical education test to the examination system through wired or wireless data transmission after the test. This process does not require invigilators to manually record the time, reducing the workload of invigilators and score entry for the middle and long distance running physical education test, and reducing the risk of human intervention in the results. When the signal sequence is inconsistent or a signal is missing, such as when a signal sequence like ABD or ABA appears, it proves that there is cheating behavior such as missing a run. At this time, the invigilator can intervene manually when checking the results later to accurately and quickly find the candidates with abnormal signals and the test time, so as to verify whether there is cheating behavior or equipment failure, without spending a lot of time reviewing the surveillance video.

[0037] Furthermore, to prevent candidates from gaining the advantage of running less distance by following the chord length instead of the arc length at curves, in addition to setting up video monitoring modules evenly spaced 100 meters apart at the connection between straight sections and curves, a video monitoring module can also be set up at the two curve positions, numbered A, A1, B, C, C1, and D in sequence. At the same time, the Bluetooth transmission power is adjusted to ensure that the A1 signal cannot be received between the straight sections AB and C1, and the C1 signal cannot be received between the straight sections CD. Taking a standard 400-meter track as an example: the diameter of the curve is about 72 meters, the arc length is 113 meters, and the chord length is 72 meters, a difference of 41 meters. At a pace of 4 minutes and 33 seconds to pass the 1000-meter race, this could save nearly 11 seconds. However, with two video monitoring modules, A1 and C1, the arc length A-A1 is only 6.5 meters longer than the chord length A-A1, and the single curve is only 13 meters longer. At a pace of 4 minutes and 33 seconds to pass the 1000-meter race, the gain from cheating is only about 3.5 seconds, but the risk of cheating remains the same. This significantly reduces the cheating benefit of candidates taking the chord length instead of the arc length at curves, which can guide candidates to take the exam honestly and further prevent cheating.

[0038] Reference Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 8In some embodiments, two gear shafts 104 are rotatably mounted inside the housing 101. Each gear shaft 104 has a gear disc 105 symmetrically mounted at both ends of its axial direction. The housing 101 has mounting holes 106 on both sides for the watch strap 2 to enter and exit the housing 101. Each gear shaft 104 is equipped with a reversible ratchet 107. The invigilator only needs to verify the candidate's and the corresponding wristband 1 code. After confirmation, the candidate wears the watch strap 2 in front of the invigilator, pushing both ends of the watch strap 2 into the housing 101 simultaneously through the mounting holes 106 on both sides. At this time, the flexible toothed rack 201 with its metal teeth and the metal connecting strip 202 embedded in the watch strap 2 form a complete and continuous conductor. Together with the two elastic contacts 117 installed inside the housing 101, they form a circuit loop. The gear disc 105 and the flexible toothed rack 201 are always in a meshing state during movement, thus forming a stable circuit. This circuit loop activates the data processing module 102, and the display screen 103 displays a startup screen, entering the exam preparation stage. As the watch strap 2 is continuously pushed in, until the flexible racks 201 on both sides of the watch strap 2 engage with the toothed disc 105, and the flexible racks 201 at both ends of the watch strap 2 are located at the upper and lower ends of the toothed disc 105 respectively, thus realizing the linkage between the toothed disc 105 and the two flexible racks 201. That is, the two ends of the watch strap 2 can simultaneously tighten or loosen the wrist. Since the reversible ratchet 107 cooperates with the toothed disc 105 to form a one-way locking, the watch strap 2 can only enter the housing 101 along the mounting hole 106 and cannot enter along the mounting hole. 106 detaches from housing 101. During the exam, the watch strap 2 is forcibly pulled out, and the watch strap 2 loses contact with the two elastic contacts 117. The two elastic contacts 117 cannot form a stable circuit, and the data processing module 102 shuts down. The data processing module 102 records the abnormal data. At this time, the invigilator can intervene manually when checking the scores later to accurately and quickly find the candidate with the abnormal signal and the exam time, so as to verify whether there is cheating or equipment failure, thereby preventing candidates from replacing the wristband 1 to cheat by taking the exam on behalf of others.

[0039] In other embodiments, the two elastic contacts 117 can be configured as a series switch instead of the aforementioned open-circuit solution. That is, after the watch strap 2 is pushed into the housing 101, it simultaneously contacts both elastic contacts 117. When both elastic contacts 117 are triggered simultaneously, the data processing module 102 is activated, and the display screen 103 shows the startup screen, entering the exam preparation stage. This solution avoids the problem of sweat from the examinee coming into contact with the watch strap 2, which could prevent the circuit from forming a stable loop, thus improving the stability of the anti-cheating system to a certain extent. However, there is a risk that if the invigilator is not attentive enough, the examinee could insert other soft rubber-like substances into the mounting hole 106 to contact the two elastic contacts 117 and activate the data processing module 102.

[0040] Reference Figure 3 and Figure 11After the watch strap 2 is pushed into the housing 101 to a tightness suitable for the examinee, the examinee can enter any area of ​​the data processing module 102 that can receive Bluetooth communication modules. The display screen 103 can display the current received signal status. The examinee pushes the reset lever 112 directly to the depth end point. Since the data processing module 102 is in the powered-on state at this time, during the process of pushing the reset lever 112 directly to the depth end point, the protrusion 114 on the reset lever 112 directly contacts the jog switch 113, the timing starts, and the examination officially begins.

[0041] Reference Figure 5 , Figure 7 and Figure 11 As the reset rod 112 is pushed into the end of the depth, the truncated cone 118 on the reset rod 112 cooperates with the flexible sheet on the chamfered surface. The flexible sheet can be made of soft materials such as silicone, rubber or high-density sponge to further prevent sweat and impurities from entering the housing 101 from the reset hole 111. As the truncated cone 118 enters the chamfer, the conical surface of the truncated cone 118 overcomes the resistance of the elastic element 120 and pushes the sliding plate 119. The sliding plate 119 moves towards the side of the watch strap 2. The sliding plate 119, together with the silicone pad 121, seals the gap between the watch strap 2 and the mounting hole 106, further preventing sweat and impurities from entering the housing 101 from the mounting hole 106 and affecting the operation of the meshing parts. At the same time, the locking teeth 122 on the slide plate 119 move downward with the slide plate 119 to lock the flexible rack 201 on the watch strap 2, preventing the rack 105 and the flexible rack 201 from disengaging due to excessive limb movement during the examination, which would cause the watch strap 2 to detach from the examinee. The displacement space of the locking teeth 122 in the direction of the watch strap 2 entering the housing 101 is one tooth pitch of the flexible rack 201. The elastic element 3 123 can increase the clearance of the flexible rack 201 and the locking teeth 122 in the horizontal direction, and can improve the meshing degree of the locking teeth 122 and the flexible rack 201.

[0042] Since the locking positions of the secondary spring lock 125 and the secondary barb groove 124 are located at the end point of the depth of the reset rod 112, the locking force of the secondary spring lock 125 and the secondary barb groove 124 can improve the locking effect of the flexible rack 201 and the locking tooth 122, and further reduce the meshing force of the ratchet body 108, thus extending the life of the ratchet body 108.

[0043] Furthermore, after completing the corresponding distance during the test, the candidate can pull out the reset lever 112 themselves, as per [reference needed]. Figure 3To stop the timing, the specific operation is as follows: pull the reset lever 112 out of the housing 101. At this time, the secondary spring lock 125 and the secondary barb groove 124 are disengaged. Further pull the reset lever 112 out of the housing 101 to the locking position of the primary spring lock 116 and the primary barb groove 115. At this time, the protrusion 114 contacts the jog switch 113, and the timing stops, ending the test. At this time, the protrusion 114 contacts the reversing lever 109, pressing the end of the reversing lever 109 away from the ratchet body 108 into the storage direction of the elastic element 110. The elastic element 110 can be a torsion spring or a spring set on the ratchet body 108 perpendicular to the reversing lever 109. At this time, the reversing lever 109 unlocks the ratchet body 108. Figure 10 When the ratchet body 108 and the gear shaft 104 are disengaged, the watch strap 2 can be freely detached from the housing 101. During the process of detaching the watch strap 2 from the housing 101, the watch strap 2 loses contact with the two elastic contacts 117. The two elastic contacts 117 cannot form a stable circuit. At this time, the data processing module 102 no longer accepts the signal from the Bluetooth communication module to avoid interference with the timing data. At the same time, the data processing module 102 sends the candidate's timing score to the examination system, and the examination ends.

[0044] In some implementations, the flexible toothed rack 201 and the watch strap 2 are integrally injection molded, and the metal connecting strip 202 is integrally molded as an implanted skeleton. The specific process can refer to the method of embedding steel wires in automobile tires. Alternatively, a patch hot pressing process can be used to implant the metal connecting strip 202 into the watch strap 2. After the flexible toothed rack 201 and the watch strap 2 are integrally injection molded, the toothed metal sheet 203 that is in contact with the flexible toothed rack 201 on the watch strap 2 is bonded or riveted to the flexible toothed rack 201. When using the bonding process, the toothed metal sheet 203 and the metal connecting strip 202 need to be bonded with conductive adhesive. When using the riveting process, copper rivets or aluminum rivets with excellent conductivity need to be used to fasten the toothed metal sheet 203 and the metal connecting strip 202.

[0045] In some implementations, to prevent the reset rod 112 from rotating axially and causing the secondary barb groove 124 to fail to engage with the secondary spring lock 125 for locking, or the primary barb groove 115 to engage with the primary spring lock 116 for locking, the reset rod 112 can be made into a U-shaped structure to prevent the reset rod 112 from rotating axially and failing to lock accurately.

[0046] refer to Figure 3 , Figure 10 and Figure 11In some implementations, the gear shaft 104 can rotate relative to the housing 101, and an intermediate tooth is installed between the two gear discs 105 on the gear shaft 104. A reversible ratchet 107 is meshed at the position of the intermediate tooth, and the reversing rod 109 of the reversible ratchet 107 is vertically arranged on the axis of the reset rod 112 under the action of the elastic element 110.

[0047] Reference Figure 8 In some implementations, two gear shafts 104 are rotatably mounted inside the housing 101. Each gear shaft 104 has a gear disc 105 symmetrically mounted at both ends of its axial direction. The housing 101 has mounting holes 106 on both sides for the watch strap 2 to enter and exit the housing 101. The flexible racks 201 of the watch straps 2 at both ends are located at the upper and lower ends of the gear disc 105, respectively, to achieve the linkage between the gear disc 105 and the two flexible racks 201 on each end of the watch strap 2. Therefore, a reversible ratchet 107 can be set on only one of the gear shafts 104. The linkage mechanism composed of the gear discs 105 of the two output shafts and the flexible racks 201 of the watch strap 2 can also achieve the effect of one ratchet meshing two gear shafts 104 in one direction. Reducing one ratchet can reduce the manufacturing cost and weight of the equipment, but it will reduce the effect of gear and rack meshing motion. In comparison, it is more suitable for female candidates with relatively lower running intensity. Furthermore, one end of the watch strap 2 can be hinged to the housing 101 as a fixed end, while the other end of the watch strap 2 is a movable section that can freely enter and exit the housing 101. This can further reduce the number of parts in the meshing structure, and further reduce the manufacturing cost and weight of the equipment. However, the adjustment range for wrist size will be reduced, making it more suitable for sports college candidates or military college candidates with smaller body size differences.

[0048] Reference Figure 5 In some implementations, the space between the secondary barb groove 124 and the secondary spring lock 125, or between the primary barb groove 115 and the primary spring lock 116, is referenced. Figure 6 The secondary spring lock 125 or the primary spring lock 116 can be achieved through a metal ball bearing and spring structure. The secondary barb groove 124 or the primary barb groove 115 can be achieved by creating a hemispherical groove on the reset rod 112 that mates with the metal ball bearing. Furthermore, markings can be drawn on the rod structure of the reset rod 112 protruding from the housing 101 to guide the examinee to confirm the current position of the reset rod 112, so as to quickly release the watch strap 2. In some implementations, the secondary spring lock 125 or the primary spring lock 116 can be omitted, and only one spring lock corresponding to two barb grooves can be set. Although this reduces the number of equipment parts, the corresponding locking force will decrease.

[0049] The various specific technical features and embodiments described in the detailed embodiments can be combined in any suitable manner without contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments / implementation methods. In order to avoid unnecessary repetition, the various possible combinations of the various specific technical features / embodiments / implementation methods in this invention will not be described separately.

Claims

1. An identity-based invigilation and anti-cheating system, characterized in that, include: The system includes a video monitoring module and a wristband. The video monitoring module is evenly distributed around the sports field and is equipped with a Bluetooth communication module. The wristband includes a housing and a strap movably connected to the housing. The strap has a flexible toothed rack that can move freely with the strap. The housing contains a data processing module that works with the Bluetooth communication module. The housing also contains a tightening unit that works with the flexible toothed rack to tighten the strap in one direction. Furthermore, the housing contains a reset unit that works with the flexible toothed rack. The reset unit releases the unidirectional tightening of the strap by the tightening unit. When the tightening unit releases the unidirectional tightening, the reset unit transmits a stop-exam signal to the data processing module. The reset unit includes a reset hole penetrating the housing, in which a reset rod cooperating with a reversing rod is slidably installed. The housing is provided with a jog switch that cooperates with the axial movement of the reset rod. The reset rod is provided with a protrusion that triggers the jog switch and the reversing rod. The jog switch and the reversing rod are located on the same normal plane of the reset rod's movement axis. The end of the reversing rod away from the ratchet body is located in the space slidably swept by the protrusion. The jog switch is electrically connected to the data processing module. The reset rod has a primary barb groove extending axially. The housing has a primary spring latch that mates with the primary barb groove. The locking position of the primary spring latch and the primary barb groove is located at the position where the reversing rod is triggered by the reset rod. The reset rod has a secondary barb groove extending axially. The housing has a secondary spring latch that mates with the secondary barb groove. The locking position of the secondary spring latch and the secondary barb groove is located at the end point of the reset rod's depth. The position where the reversing rod is triggered by the reset rod and the end point of the reset rod's depth are staggered. The flexible toothed strip on the watch strap is recessed into the inner surface of the watch strap, and the tooth tip circle is flush with the outer surface of the watch strap. The flexible toothed strip has a metal tooth surface and its length is in the same direction as the length of the housing. The edge of the watch strap is provided with a metal connecting strip that fits the shape of the watch strap and connects the tooth surfaces of the flexible toothed strips at both ends. The housing is provided with elastic contacts that cooperate with the two flexible toothed strips. The two elastic contacts are electrically connected to the data processing module and are used to start and stop the data processing module.

2. The invigilation and anti-cheating system based on identity binding according to claim 1, characterized in that: The tightening unit includes a gear shaft, at least one gear shaft is rotatably mounted in the housing, and gear discs are symmetrically mounted at both ends of the gear shaft along its axial direction. The housing has mounting holes for the watch strap to enter and exit the housing. At least one end of each side of the watch strap has a flexible rack that cooperates with the gear discs along its length. The gear shaft is provided with a reversible ratchet, which includes a ratchet body and a reversing lever. A reversing lever for controlling the meshing direction is rotatably mounted on the ratchet body. An elastic element is installed between the reversing lever and the ratchet body. The elastic element is used to press the reversing lever so that the ratchet body is in a normally engaged state.

3. The invigilation and anti-cheating system based on identity binding according to claim 1, characterized in that: The metal connecting strip is made of shape memory metal and is embedded in the watch strap.

4. The invigilation and anti-cheating system based on identity binding according to claim 1, characterized in that: The reset rod has a frustum on one end of the rod outside the watch band. The small end face of the frustum faces the housing. The wall of the reset hole has a chamfer that mates with the frustum. The chamfered surface has a flexible sheet. When the reset rod is at the end of the depth, the frustum and the chamfer are in contact. A sliding plate that mates with the frustum is slidably installed on the inner wall of the housing. The sliding plate has a silicone pad on the side facing the watch band. An elastic element two is provided inside the housing to push the sliding plate away from the watch band.

5. The invigilation and anti-cheating system based on identity binding according to claim 4, characterized in that: The sliding plate has a locking tooth that engages with the watch strap on the side facing the watch strap. The sliding direction of the locking tooth is the direction in which the watch strap enters the housing. An elastic element is provided between the locking tooth and the sliding plate. The displacement space of the locking tooth in the direction in which the watch strap enters the housing is one tooth pitch of the flexible rack.

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