A double-hall position-limiting sensing method for preventing overtravel failure

Abstract

The application discloses a double-Hall limit position sensing method for preventing over-travel failure, belongs to the technical field of Hall limit position sensing, and comprises an ascending edge detection module for input preprocessing, filtering of signal burrs, response to a real trigger edge, output of sequence judgment timing, a sequence latching module for judging the movement direction of a reading head through Hall trigger sequence judgment, output of latching or resetting basis, a conditional trigger module for generating a control signal in an effective scene where both Halls are triggered, to avoid false triggering, a limit latching module for continuously latching a high level after over-limiting, and an operation output module for outputting a high level when a first Hall switch is triggered when no over-travel occurs, still outputting a high level when the Hall becomes low, outputting a low level when the Hall becomes low after limit resetting, and enabling the limit protection of both sides in linear motion to be realized by selecting single-pole Hall switches with different magnetic pole actions.

Description

Technical Field

[0001] This application belongs to the field of Hall limit sensing technology, specifically, it relates to a dual Hall limit sensing method to prevent overtravel failure. Background Technology

[0002] The travel protection limit switch of the grating ruler displacement sensor is a device that limits the movement range of the grating ruler reading head and prevents the reading head from being damaged due to overtravel.

[0003] However, mechanical switch limiters rely on mechanical contact to open and close contacts, which can lead to mechanical wear, contact vibration, and the risk of damage. Photoelectric gate limiters rely on photoelectric blocking and switching, which are easily contaminated and require additional light-blocking plates. Current protection limiters detect stall current, which may cause overload conditions and accelerate aging when triggered, resulting in low reliability. A single Hall effect switch will lose signal after overtravel, requiring additional processing to determine its location. For systems with large inertia, the sensor may overtravel beyond the magnet's sensing range, thus emitting a normal signal outside the limit range. When the read head overtravels, the Hall effect immediately outputs a low level, the limit signal is lost, and the device may become uncontrollable. Summary of the Invention

[0004] To address the aforementioned problems and technical deficiencies, this application adopts the following technical solution: a dual Hall effect limit sensing method for preventing overtravel failure, comprising two Hall switches, and further comprising: The rising edge detection module performs input preprocessing, filters signal glitches, responds to the actual trigger edge, and outputs the sequence to determine timing. The sequential latch module uses Hall effect triggering to determine the direction of the read head movement and outputs the latching or resetting criteria. The condition triggering module generates a control signal in a valid scenario where both Hall effect sensors are triggered, thus preventing false triggering. The limit latch module continuously latches a high level after the limit is exceeded; When the operation output module is not overtraveled, the first Hall switch is triggered, and the output level is high. When the Hall switch goes low, the output level is still high. After the limit is reset, the Hall switch goes low, and the output level is low.

[0005] Preferably, the rising edge detection module includes: a delay unit, an inverter, and an AND gate.

[0006] Furthermore, the direction latch module includes an RS flip-flop; If the rising edge of the first Hall switch arrives first, the sequence is latched; If the rising edge of the second Hall switch arrives first, the sequence is latched.

[0007] Furthermore, the condition triggering module includes two AND gates; When the device moves toward the limit position and the second Hall switch is triggered, the first AND gate outputs 1, generating a set signal. When the device moves away from the limit position and the first Hall switch is triggered, the second AND gate outputs 1, generating a reset signal.

[0008] Furthermore, the circuit composition of the limit latch module includes: an RS flip-flop; When S outputs 1 and R is 0, Q outputs 1 and remains high. When R outputs 1 and S is 0, Q outputs 0, returning to a low level.

[0009] Preferably, the circuit composition of the arithmetic output module includes: a three-input OR gate; Limit outputs the first Hall switch, the second Hall switch, and the latch signal.

[0010] Compared to existing technologies, the beneficial effects of this application are as follows: The limit sensing method of the dual Hall switch in this application is an improvement on the single Hall scheme. It not only has the original characteristics of single Hall, such as non-contact, wear-free and strong anti-pollution capability, but also improves the safety redundancy of limit sensing. By judging whether the overtravel is detected by the position information of dual Hall, the reliability of it as a limit sensor is improved. It can provide alarm and hold for amplitude overtravel, reducing the computational burden of the main control. The dual Hall scheme can achieve limit protection on both sides during linear motion by selecting single Hall switches that operate on different magnetic poles. Attached Figure Description

[0011] In the attached diagram: Figure 1 This is a circuit diagram of an embodiment of this application; Figure 2 This is a flowchart illustrating an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an embodiment of this application. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments. Generally, the components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0013] Examples, such as Figure 1 and Figure 3 As shown, a dual Hall effect limit sensing method for preventing overtravel failure includes two Hall switches, and further includes: The rising edge detection module performs input preprocessing, filters signal glitches, responds to the actual trigger edge, and outputs the sequence to determine timing. The rising edge detection module includes: a delay unit, an inverter, and an AND gate.

[0014] The sequential latch module uses Hall effect triggering to determine the direction of the read head movement and outputs the latching or resetting criteria. The direction latch module includes an RS flip-flop; If the rising edge of the first Hall switch arrives first, the sequence is latched; If the rising edge of the second Hall switch arrives first, the sequence is latched.

[0015] The condition triggering module generates a control signal in a valid scenario where both Hall effect sensors are triggered, thus preventing false triggering. The condition triggering module includes two AND gates; When the device moves toward the limit position and the second Hall switch is triggered, the first AND gate outputs 1, generating a set signal. When the device moves away from the limit position and the first Hall switch is triggered, the second AND gate outputs 1, generating a reset signal.

[0016] The limit latch module continuously latches a high level after the limit is exceeded; The circuit components of the limit latch module include: an RS flip-flop; When S outputs 1 and R is 0, Q outputs 1 and remains high. When R outputs 1 and S is 0, Q outputs 0, returning to a low level.

[0017] When the operation output module is not overtraveled, the first Hall switch is triggered, and the output level is high. When the Hall switch goes low, the output level is still high. After the limit is reset, the Hall switch goes low, and the output level is low.

[0018] The circuit composition of the arithmetic output module includes: a three-input OR gate; Limit outputs the first Hall switch, the second Hall switch, and the latch signal.

[0019] like Figure 2 As shown, in the initial state, the read head is at zero point, far from the limit switch, and the outputs of the first Hall switch and the second Hall switch are both 0, making the edge detection output 0 and the limit switch output 0, indicating invalidity; When the reading head moves to the left and is limited to point P to the left, the first Hall switch is triggered first, and the output changes from 0 to 1. The second Hall switch outputs 0. When the detection output pulse is detected, the limit output is 1, the Hall is triggered, and the limit is effective. Then the second Hall switch is triggered, and the output of the second Hall switch changes from 0 to 1. The output of the first Hall switch remains 1. Along the detection output pulse, the limit output is 1, which remains effective. When the read head moves to the left beyond the limit and leaves point P, the outputs of the first Hall switch and the second Hall switch change from 1 to 0 in sequence, the limit output is 0, and it remains at a high level after the overtravel, so the limit remains effective. When the reading head leaves the limit position and returns to the zero position from the right limit position, the second Hall switch output changes from 0 to 1, the first Hall switch outputs 0, and along the detection output pulse, the limit output is 0, and the limit is still effective; Then the first Hall switch output changes from 0 to 1, the second Hall switch remains 1, along with the detection output pulse, the limit output is 1, the Hall is triggered, and it is still effective; When the read head leaves and returns to zero, the outputs of the second Hall switch and the first Hall switch change sequentially from 1 to 0. The limit output is 0, the device is reset, and the limit switch becomes invalid.

[0020] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications, improvements, and substitutions without departing from the concept of this application, and these all fall within the protection scope of this application.

Claims

1. A dual Hall effect limit sensing method for preventing overtravel failure, characterized in that, Including two Hall switches, and also: The rising edge detection module performs input preprocessing, filters signal glitches, responds to the actual trigger edge, and outputs the sequence to determine timing. The sequential latch module uses Hall effect triggering to determine the direction of the read head movement and outputs the latching or resetting criteria. The condition triggering module generates a control signal in a valid scenario where both Hall effect sensors are triggered, thus preventing false triggering. The limit latch module continuously latches a high level after the limit is exceeded; When the operation output module is not overtraveled, the first Hall switch is triggered, and the output level is high. When the Hall switch goes low, the output level is still high. After the limit is reset, the Hall switch goes low, and the output level is low.

2. The dual Hall effect limit sensing method for preventing overtravel failure according to claim 1, characterized in that, The rising edge detection module includes: a delay unit, an inverter, and an AND gate.

3. The dual Hall effect limit sensing method for preventing overtravel failure according to claim 1, characterized in that, The direction latch module includes an RS flip-flop; If the rising edge of the first Hall switch arrives first, the sequence is latched; If the rising edge of the second Hall switch arrives first, the sequence is latched.

4. The dual Hall effect limit sensing method for preventing overtravel failure according to claim 3, characterized in that, The condition triggering module includes two AND gates; When the device moves toward the limit position and the second Hall switch is triggered, the first AND gate outputs 1, generating a set signal. When the device moves away from the limit position and the first Hall switch is triggered, the second AND gate outputs 1, generating a reset signal.

5. The dual Hall effect limit sensing method for preventing overtravel failure according to claim 4, characterized in that, The circuit composition of the limit latch module includes: an RS flip-flop; When S outputs 1 and R is 0, Q outputs 1 and remains high. When R outputs 1 and S is 0, Q outputs 0, returning to a low level.

6. The dual Hall effect limit sensing method for preventing overtravel failure according to claim 1, characterized in that, The circuit composition of the arithmetic output module includes: a three-input OR gate; Limit outputs the first Hall switch, the second Hall switch, and the latch signal.

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