Elevator shaft absolute value measuring system based on ToF laser ranging technology

Abstract

The invention provides an elevator shaft absolute value measuring system based on a ToF laser ranging technology, and relates to the field of elevator control. The system comprises a controller, a laser distance measuring device, an acceleration measuring device, a speed limiter and electronic safety tongs, the width of laser pulses emitted by the laser distance measuring device is fixed and is slightly influenced by the environment, the measuring precision and reliability of the laser distance measuring device are effectively improved, and measuring errors caused by unstable pulse width are avoided; the acceleration measuring device measures the actual acceleration of the elevator car in real time and is combined with a quick response mechanism of the speed limiter and the electronic safety tongs, the speed limiter is used for limiting the speed of the elevator, the electronic safety tongs are used for emergency braking, and the running safety of the elevator is effectively improved. By means of the measuring system, the measuring precision of the laser distance measuring device can be kept in a complex environment, overspeed operation of the elevator car can be quickly responded, and the risk of accidents in the elevator operation process is effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of elevator control, and in particular to an elevator shaft absolute value measurement system based on ToF laser ranging technology. Background Art

[0002] As an important vertical transportation tool in modern buildings, the safety and reliability of elevator operation are directly related to the safety of life and property of users. To ensure the safe operation of elevators, it is necessary to monitor the speed, position, acceleration and other parameters of the elevator in real time. Among them, the laser ranging device has become one of the core components of the elevator shaft absolute value measurement system based on ToF laser ranging technology due to its advantages of high measurement accuracy, fast response speed and strong anti-interference ability.

[0003] In the related art, the laser distance measuring device realizes the absolute value measurement between the elevator car and the top or bottom of the elevator shaft by emitting laser pulses and receiving echo signals. However, the existing laser distance measuring device has the problem of unstable laser pulse width, especially in complex working environments such as high temperature, low temperature or vibration in the elevator shaft. The laser emission circuit is easily affected by external interference or its own parameter drift, causing the laser pulse width to fluctuate, resulting in poor measurement accuracy of the laser emission time and the laser reception time, thereby reducing the measurement accuracy and reliability of the laser distance measuring device.

[0004] Therefore, in the process of absolute value measurement of the elevator shaft, the laser pulse width of the laser ranging device is not fixed, the measurement accuracy is low, and the reliability is poor, which become problems that need to be solved urgently. Summary of the invention

[0005] The present application provides an elevator shaft absolute value measurement system based on ToF laser ranging technology to solve the problems of non-fixed laser pulse width, low measurement accuracy and poor reliability of laser ranging devices in the prior art.

[0006] The present application provides an elevator shaft absolute value measurement system based on ToF laser ranging technology, including: a controller, a laser ranging device, an acceleration measurement device, a speed limiter and an electronic safety clamp;

[0007] The laser distance measuring device is used to measure the distance between the elevator car and the top or bottom of the elevator shaft, and the laser distance measuring device includes a laser transmitting circuit, a laser receiving circuit and a time conversion module;

[0008] The input end of the laser emitting circuit is electrically connected to the first output end of the controller, the output end of the laser emitting circuit is used to emit an outgoing laser to a reflector, the receiving end of the laser receiving circuit is used to receive an echo laser reflected by the reflector, the output end of the laser receiving circuit is electrically connected to the first input end of the time conversion module, the second input end of the time conversion module is electrically connected to the second output end of the controller, and the output end of the time conversion module is electrically connected to the first input end of the controller; the time conversion module is used to determine the distance between the elevator car and the top or bottom of the elevator shaft based on the emission time of the outgoing laser and the reception time of the echo laser;

[0009] The acceleration measuring device is installed on the elevator car, the output end of the acceleration measuring device is electrically connected to the second input end of the controller, and the acceleration measuring device is used to measure the actual acceleration of the elevator car and output the actual acceleration of the elevator car to the controller;

[0010] The speed limiter and the electronic safety clamp are electrically connected to the third output terminal of the controller respectively, and the controller is used to control the speed limiter and / or the electronic safety clamp to operate when the actual acceleration is greater than the preset acceleration, so as to stop the elevator car.

[0011] In one possible design, the laser emission circuit includes a first trigger, a dual-path comparator, a laser driver, and a laser emitter;

[0012] The first input end of the first trigger is electrically connected to the first output end of the controller, the output end of the first trigger is electrically connected to the input end of the dual-way comparator, the first output end and the second output end of the dual-way comparator are electrically connected to the input end of the laser driver respectively, the output end of the laser driver is electrically connected to the input end of the laser emitter, and the output end of the laser emitter is used to emit an outgoing laser to the reflector;

[0013] The controller is used to output a first pulse signal to the first trigger; the first trigger is used to generate a step signal based on the rising edge of the first pulse signal; the dual-way comparator is used to generate a first drive signal and a second drive signal based on the step signal, and the first output end of the dual-way comparator outputs the first drive signal at a first moment, and the second output end of the dual-way comparator outputs the second drive signal at a second moment, and the second moment is after the first moment; the laser driver is used to generate a second pulse signal based on the first drive signal and the second drive signal, and drive the laser emitter to emit an outgoing laser based on the second pulse signal; wherein the pulse width of the second pulse signal is equal to the time interval between the second moment and the first moment.

[0014] In one possible design, the laser emission circuit further includes a resetter;

[0015] The first input end of the resetter is electrically connected to the first output end of the controller, the second input end of the resetter is electrically connected to the first output end of the dual comparator, the third input end of the resetter is electrically connected to the second output end of the dual comparator, the first output end of the resetter is electrically connected to the second input end of the first trigger, and the second output end and the third output end of the resetter are electrically connected to the input end of the laser driver respectively;

[0016] The resetter is used to generate a reset signal based on the first pulse signal, and reset the first trigger through the reset signal to stop the laser emitter from working.

[0017] In one possible design, the resetter includes an inverter, a second trigger, a first AND gate, and a second AND gate;

[0018] The first input end of the inverter is electrically connected to the first output end of the controller, the first output end of the inverter is electrically connected to the first input end of the second trigger, the output end of the second trigger is electrically connected to the second input end of the inverter, and the second output end of the inverter is electrically connected to the second input end of the first trigger, the second input end of the second trigger, the first input end of the first AND gate, and the first input end of the first AND gate respectively;

[0019] The second input end of the first AND gate is electrically connected to the first output end of the dual comparator, the second input end of the second AND gate is electrically connected to the second output end of the dual comparator, and the output end of the first AND gate and the output end of the second AND gate are electrically connected to the input end of the laser driver respectively.

[0020] In one possible design, the laser receiving circuit includes a laser receiver, a harmonic suppression circuit, a signal amplification circuit, and a first comparator;

[0021] The output end of the laser receiver is electrically connected to the input end of the harmonic suppression circuit, the output end of the harmonic suppression circuit is electrically connected to the input end of the signal amplification circuit, the output end of the signal amplification circuit is electrically connected to the first input end of the first comparator, the second input end of the first comparator is used to access the first reference voltage, and the output end of the first comparator is electrically connected to the first input end of the time conversion module;

[0022] The laser receiver is used to receive the echo laser reflected by the reflecting plate, and convert the optical signal of the echo laser into a first echo signal; the harmonic suppression circuit is used to suppress the high-frequency interference signal in the first echo signal to obtain a second echo signal; the signal amplification circuit is used to amplify the second echo signal to obtain a third echo signal; the first comparator is used to compare the third echo signal with the first reference voltage to obtain a target echo signal, and output the target echo signal to the time conversion module.

[0023] In a possible design, the third output terminal of the controller is electrically connected to the speed limiter and / or the electronic safety clamp through a control circuit;

[0024] In the case that the actual acceleration measured by the acceleration measuring device is greater than the preset acceleration, the controller controls the speed limiter and / or the electronic safety clamp to operate through the control circuit to stop the elevator car.

[0025] In a possible design, the control circuit includes a first switch tube, a first diode and a second diode;

[0026] The first switch tube is an NPN transistor or an NMOS tube, a first end of the first switch tube is electrically connected to the third output end of the controller, a second end of the first switch tube is grounded, and a third end of the first switch tube is electrically connected to the first end of the first diode;

[0027] The second end of the first diode is electrically connected to the first end of the load device, and the second end of the load device is connected to the input voltage; wherein the load device is the speed limiter or the electronic safety clamp;

[0028] The first end of the second diode is electrically connected to the fourth output end of the controller, and the second end of the second diode is connected to the input voltage.

[0029] In a possible design, the control circuit includes a second switch tube, a third diode and a fourth diode;

[0030] The second switch tube is a PNP transistor or a PMOS tube, a first end of the second switch tube is electrically connected to the third output end of the controller, a second end of the second switch tube is electrically connected to the first end of the fourth diode, and a third end of the second switch tube is electrically connected to the first end of the third diode;

[0031] The second end of the third diode is electrically connected to the first end of the load device, and the second end of the load device is grounded; wherein the load device is the speed limiter or the electronic safety clamp;

[0032] The first end of the fourth diode is also electrically connected to the fourth output end of the controller, and the second end of the fourth diode is connected to the input voltage.

[0033] In one possible design, the control circuit includes a source relay and a fifth switch tube;

[0034] The first input end of the source type relay is electrically connected to the third output end of the controller, the second input end of the source type relay is connected to the input voltage, the first output end of the source type relay is electrically connected to the first end of the speed limiter, the second output end of the source type relay is electrically connected to the first end of the electronic safety clamp, and the second end of the speed limiter and the second end of the electronic safety clamp are both grounded;

[0035] The first end of the fifth switch tube is connected to the input voltage, and the second end of the fifth switch tube is electrically connected to the fourth output end of the controller.

[0036] In one possible design, the control circuit includes a leakage relay and a sixth switch tube;

[0037] The first input end of the leakage type relay is electrically connected to the third output end of the controller, the second input end of the leakage type relay is grounded, the first output end of the leakage type relay is electrically connected to the first end of the speed limiter, the second output end of the leakage type relay is electrically connected to the first end of the electronic safety clamp, and the second end of the speed limiter and the second end of the electronic safety clamp are respectively connected to the input voltage;

[0038] The first end of the sixth switch tube is connected to the input voltage, and the second end of the sixth switch tube is electrically connected to the fourth output end of the controller.

[0039] The embodiment of the present application provides an elevator shaft absolute value measurement system based on ToF laser ranging technology, which includes a controller, a laser ranging device, an acceleration measurement device, a speed limiter and an electronic safety clamp. The laser pulse width emitted by the laser ranging device is fixed and less affected by the environment, which effectively improves the measurement accuracy and reliability of the laser ranging device and avoids measurement errors caused by unstable pulse width; the acceleration measurement device measures the actual acceleration of the elevator car in real time, and combines the rapid response mechanism of the speed limiter and the electronic safety clamp. The speed limiter is used to limit the elevator speed, and the electronic safety clamp is used for emergency braking, which effectively improves the safety of elevator operation. Through the measurement system of the present application, not only can the measurement accuracy of the laser ranging device be maintained in a complex environment, but also the overspeed operation of the elevator car can be quickly responded to, which effectively reduces the risk of accidents during the operation of the elevator and provides reliable protection for the safe operation of the elevator. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A circuit principle block diagram of an elevator shaft absolute value measurement system based on ToF laser ranging technology provided in an embodiment of the present application;

[0041] Figure 2 A circuit principle block diagram of another elevator shaft absolute value measurement system based on ToF laser ranging technology provided in an embodiment of the present application;

[0042] Figure 3 A circuit principle block diagram of a laser emission circuit and a controller provided in an embodiment of the present application;

[0043] Figure 4 A circuit principle block diagram of another laser emission circuit and controller provided in an embodiment of the present application;

[0044] Figure 5 A circuit principle block diagram of a laser receiving circuit provided in an embodiment of the present application;

[0045] Figure 6 A circuit schematic diagram of a control circuit provided in an embodiment of the present application;

[0046] Figure 7 A circuit schematic diagram of another control circuit provided in an embodiment of the present application;

[0047] Figure 8 A circuit schematic diagram of another control circuit provided in an embodiment of the present application;

[0048] Fig. 9 A circuit schematic diagram of another control circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0051] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0052] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists, A and B can exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0053] In addition, the terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0054] In the description of this application, unless otherwise specified, "multiple" and "at least two" mean more than two (including two). Similarly, "multiple groups" and "at least two groups" mean more than two groups (including two).

[0055] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, "connected" or "connection" can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] In order to make those skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings. It should be noted that different technical features in the present application can be combined with each other without conflict.

[0057] Figure 1 A schematic diagram of a flow chart of an elevator shaft absolute value measurement system based on ToF laser ranging technology provided in an embodiment of the present application. Figure 1 As shown, the elevator shaft absolute value measurement system based on ToF laser ranging technology provided in the embodiment of the present application includes a controller 10, a laser ranging device 20, an acceleration measurement device 30, a speed limiter 40 and an electronic safety clamp 50;

[0058] The laser distance measuring device 20 is used to measure the distance between the elevator car and the top or bottom of the elevator shaft. The laser distance measuring device 20 includes a laser emitting circuit 21, a laser receiving circuit 22 and a time conversion module 23.

[0059] The input end of the laser emitting circuit 21 is electrically connected to the first output end of the controller 10, the output end of the laser emitting circuit 21 is used to emit an outgoing laser to the reflecting plate, the receiving end of the laser receiving circuit 22 is used to receive the echo laser reflected by the reflecting plate, the output end of the laser receiving circuit 22 is electrically connected to the first input end of the time conversion module 23, the second input end of the time conversion module 23 is electrically connected to the second output end of the controller 10, and the output end of the time conversion module 23 is electrically connected to the first input end of the controller 10.

[0060] The acceleration measuring device 30 is installed on the elevator car, and the output end of the acceleration measuring device 30 is electrically connected to the second input end of the controller 10 . The acceleration measuring device 30 is used to measure the actual acceleration of the elevator car and output the actual acceleration of the elevator car to the controller 10 .

[0061] The speed limiter 40 and the electronic safety clamp 50 are electrically connected to the third output terminal of the controller 10 respectively. The controller 10 is used to control the speed limiter 40 and / or the electronic safety clamp 50 to stop the elevator car when the actual acceleration is greater than the preset acceleration.

[0062] Among them, the controller 10 can be implemented by at least one hardware form of a Field Programmable Gate Array (FPGA) chip, a Digital Signal Processing (DSP) chip, a Programmable Logic Controller (PLC), and an Advanced Reduced Instruction Set Machine (ARM), and this embodiment does not make any specific limitations on this.

[0063] The laser distance measuring device 20 is used to measure the distance between the elevator car and the top or bottom of the elevator shaft.

[0064] It should be noted that when installing the laser ranging device 20 and the reflector, the laser ranging device 20 can be set in the elevator shaft, and the reflector and the laser ranging device 20 can be set on the elevator car accordingly; the laser ranging device 20 can also be set in the elevator car, and the reflector and the laser ranging device 20 can be set in the elevator shaft accordingly. This embodiment does not make any specific limitations on this.

[0065] In this embodiment, the laser distance measuring device 20 can obtain the distance between the elevator car and the top or bottom of the elevator shaft by measuring the distance between the laser distance measuring device 20 and the reflector.

[0066] It should be noted that the first input end of the time conversion module 23 is electrically connected to the output end of the laser receiving circuit 22, and is used to obtain the laser receiving moment of the laser receiving circuit 22 from the laser receiving circuit 22; the second input end of the time conversion module 23 is electrically connected to the second output end of the controller 10, and is used to obtain the laser emission moment of the laser emission circuit 21 from the controller 10, so that the time conversion module 23 can determine the flight time from the laser ranging device 20 to the reflector based on the laser receiving moment and the laser emission moment.

[0067] The output end of the time conversion module 23 is electrically connected to the first input end of the controller 10, and is used to determine the distance between the elevator car and the top or bottom of the elevator shaft based on the emission time of the emitted laser and the reception time of the echo laser. The time conversion module 23 sends the flight time from the laser ranging device 20 to the reflector to the controller 10, so that the controller 10 determines the distance between the elevator car and the top or bottom of the elevator shaft according to the flight time.

[0068] In the prior art, the laser receiving circuit needs to send the laser receiving time to the controller, which then forwards it to the time conversion module. However, the time conversion module 23 of the present application can directly obtain the laser receiving time from the laser receiving circuit 22, eliminating the link of transferring through the controller, avoiding the time delay caused by data transmission and processing, and effectively improving the accuracy of the measured flight time, thereby improving the measurement accuracy and reliability of the laser ranging device.

[0069] The acceleration measuring device 30 is used to measure the actual acceleration of the elevator car in real time during the operation of the elevator, and send the actual acceleration of the elevator car to the controller 10.

[0070] It should be noted that the controller 10 can determine whether the elevator car is running at an overspeed based on the actual acceleration and the preset acceleration.

[0071] When the actual acceleration does not exceed the preset acceleration, the controller 10 determines that the elevator car is operating normally; when the actual acceleration exceeds the preset acceleration, the controller 10 determines that the elevator car is operating at an overspeed (such as the elevator car is freely falling or rising too quickly).

[0072] Specifically, the third output terminal of the controller 10 is used to output high and low level signals indicating whether the elevator car is running at overspeed.

[0073] In a possible implementation, when the elevator car operates normally, the control signal output by the third output terminal of the controller 10 is a low-level signal; when the elevator car operates at an overspeed, the control signal output by the third output terminal of the controller 10 is a high-level signal.

[0074] In another possible implementation, when the elevator car operates normally, the control signal output by the third output terminal of the controller 10 is a high-level signal; when the elevator car operates at an overspeed, the control signal output by the third output terminal of the controller 10 is a low-level signal.

[0075] The speed limiter 40 is a mechanical device. When the elevator car is running at an overspeed, the speed limiter will trigger corresponding safety measures, such as starting a mechanical brake device to ensure that the elevator stops running.

[0076] The electronic safety clamp 50 is a safety device specially used for emergency braking of an elevator. When the elevator car is running at an overspeed, the electronic safety clamp 50 can also trigger corresponding safety measures to ensure that the elevator stops running.

[0077] It should be noted that the speed limiter 40 plays a preventive protection role, and the electronic safety clamp 50 is the final safety device. The speed limiter 40 and the electronic safety clamp 50 are coordinated by the controller 10 to ensure the safety and reliability of the elevator operation.

[0078] The embodiment of the present application provides an elevator shaft absolute value measurement system based on ToF laser ranging technology, which includes a controller, a laser ranging device, an acceleration measurement device, a speed limiter and an electronic safety clamp. The laser pulse width emitted by the laser ranging device is fixed and less affected by the environment, which effectively improves the measurement accuracy and reliability of the laser ranging device and avoids the measurement error caused by the unstable pulse width; the acceleration measurement device measures the actual acceleration of the elevator car in real time, and combines the fast response mechanism of the speed limiter and the electronic safety clamp. The speed limiter is used to limit the elevator speed, and the electronic safety clamp is used for emergency braking, which effectively improves the safety of the elevator operation. Through the elevator shaft absolute value measurement system based on ToF laser ranging technology of this application, it is not only possible to maintain the measurement accuracy of the laser ranging device in complex environments (such as high temperature, low temperature or vibration), but also to quickly respond to the overspeeding of the elevator car, effectively reducing the risk of accidents during the operation of the elevator, and providing reliable protection for the safe operation of the elevator.

[0079] Figure 2 A flow chart of another elevator shaft absolute value measurement system based on ToF laser ranging technology provided in an embodiment of the present application. Figure 2 As shown, the elevator shaft absolute value measurement system based on ToF laser ranging technology also includes a communication module 60 and a power supply 70.

[0080] The first end of the communication module 60 is electrically connected to the controller 10, and the second end of the communication module 60 is electrically connected to the elevator main control system. The communication module 60 is used for data transmission between the controller 10 and the elevator main control system.

[0081] It should be noted that the present application uses the communication module 60 to feed back the actual acceleration of the elevator car measured by the acceleration measurement device 30 and the position information of the elevator car measured by the laser ranging device 20 to the elevator master control system, so that the elevator master control system can control the stopping position of the elevator car according to the actual acceleration and position information of the elevator car.

[0082] The communication module 60 may adopt different communication protocols, which is not specifically limited in this embodiment.

[0083] For example, the communication module 60 may be a CAN communication module, an RS485 communication module, or an RS232 communication module.

[0084] The power supply 70 is used to power the controller 10 to ensure the normal operation of the elevator shaft absolute value measurement system based on ToF laser ranging technology.

[0085] Figure 3 The circuit principle block diagram of a laser emission circuit and a controller provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, in a possible embodiment, the laser emission circuit 21 includes a first trigger 211 , a dual-path comparator 212 , a laser driver 213 and a laser emitter 214 .

[0086] The first input end of the first trigger 211 is electrically connected to the first output end of the controller 10, the output end of the first trigger 211 is electrically connected to the input end of the dual-way comparator 212, the first output end and the second output end of the dual-way comparator 212 are electrically connected to the input end of the laser driver 213 respectively, the output end of the laser driver 213 is electrically connected to the input end of the laser emitter 214, and the output end of the laser emitter 214 is used to emit an outgoing laser to the reflector.

[0087] The controller 10 is used to output a first pulse signal to the first trigger 211; the first trigger 211 is used to generate a step signal based on the rising edge of the first pulse signal; the dual comparator 212 is used to generate a first drive signal and a second drive signal based on the step signal, and the first output end of the dual comparator 212 outputs the first drive signal at a first moment, and the second output end of the dual comparator 212 outputs the second drive signal at a second moment, and the second moment is after the first moment; the laser driver 213 is used to generate a second pulse signal based on the first drive signal and the second drive signal, and drive the laser emitter 214 to emit an outgoing laser based on the second pulse signal; wherein the pulse width of the second pulse signal is equal to the time interval between the second moment and the first moment.

[0088] Among them, the first pulse signal is a wide pulse signal output by the controller 10. The pulse width of the first pulse signal is relatively wide. Due to the insufficient stability of the clock source inside the controller 10 and the influence of temperature changes, the pulse width of the first pulse signal is not stable and will further deteriorate with temperature changes.

[0089] It should be noted that if the laser driver 213 directly drives the laser emitter 214 to emit laser based on the first pulse signal, due to the unstable width of the first pulse signal, the laser emission time and laser reception time received by the time conversion module 23 will be inaccurate, thereby introducing measurement errors, resulting in reduced measurement accuracy and reliability of the laser ranging device 20.

[0090] The first trigger 211 is a D trigger.

[0091] It should be noted that the first trigger 211 is used to use the rising edge of the first pulse signal as a trigger point to generate a step signal. The step signal is a voltage signal that changes linearly from 0V to 3.3V, has a fixed rising time, and is not affected by the pulse width jitter of the first pulse signal.

[0092] In this embodiment, the first trigger 211 only responds to the rising edge of the first pulse signal, which can eliminate the pulse width jitter of the first pulse signal; and the rising time of the step signal is fixed and is less affected by environmental changes such as external temperature, which helps to provide a reliable input signal for the subsequent dual comparator 212.

[0093] The dual comparator 212 is used to generate a first driving signal and a second driving signal based on the step signal output by the first trigger 211 .

[0094] It should be noted that the dual comparator 212 may include a second comparator and a third comparator. The step signal output by the first trigger 211 is simultaneously input to the first input terminal of the second comparator and the first input terminal of the third comparator, the second input terminal of the second comparator is connected to the second reference voltage, the second input terminal of the third comparator is connected to the third reference voltage, and the second reference voltage is less than the third reference voltage.

[0095] The output end of the second comparator is the first output end of the dual comparator 212. The second comparator is used to detect whether the voltage of the step signal output by the first trigger 211 exceeds the second reference voltage, and output the first drive signal when the voltage of the step signal output by the first trigger 211 exceeds the second reference voltage (i.e., the first moment).

[0096] The output end of the third comparator is the second output end of the dual comparator 212. The third comparator is used to detect whether the voltage of the step signal output by the first trigger 211 exceeds the third reference voltage, and output the second drive signal when the voltage of the step signal output by the first trigger 211 exceeds the third reference voltage (i.e., the second moment).

[0097] The second reference voltage and the third reference voltage can be set by the user, and are not specifically limited in this embodiment.

[0098] For example, when the step signal changes linearly from 0V to 3.3V, the rise time of the step signal is 50ns, and the pulse width of the second pulse signal expected by the user is 10ns, that is, the time interval between the second moment and the first moment is 10ns. Therefore, when the time required for the step signal to change linearly from 1V to 2V is 10ns, the second reference voltage is set to 1V, and the third reference voltage is set to 2V. At this time, the time interval between the first moment when the first output terminal of the dual comparator 212 outputs the first drive signal and the second moment when the second output terminal of the dual comparator 212 outputs the second drive signal is 10ns, and the pulse width of the second pulse signal generated by the subsequent laser driver 213 based on the first drive signal and the second drive signal is also 10ns.

[0099] In this embodiment, the time interval between the first moment when the dual comparator 212 outputs the first drive signal and the second time when the dual comparator 212 outputs the second drive signal is determined by the voltage range formed by the second reference voltage and the third reference voltage of the dual comparator 212, and the rise time of the step signal output by the first trigger 211, and has nothing to do with the pulse width of the first pulse signal. Therefore, the pulse width of the second pulse signal generated subsequently is fixed, and the accuracy of the laser emission moment and the laser reception moment received by the time conversion module 23 is high, which effectively improves the measurement accuracy and reliability of the laser ranging device 20.

[0100] The laser driver 213 is used to receive the first driving signal and the second driving signal, and generate a second pulse signal according to the time interval between the first driving signal and the second driving signal, wherein the pulse width of the second pulse signal is equal to the time interval between the second moment and the first moment.

[0101] It should be noted that the laser driver 213 is also used to control the starting time, duration, repetition frequency and other parameters of the laser emitter 214 based on the second pulse signal to ensure that the laser emitter 214 emits the laser in the manner required by the user.

[0102] The laser emitter 214 emits laser light toward the reflector according to the pulse width of the second pulse signal.

[0103] It should be noted that the laser emitter 214 can be at least one of a laser diode (Laser Diode, LD), an edge emitting laser (Edge Emitting Lasers, EEL) and a vertical cavity surface emitting laser (Vertical Cavity Surface Emitting Laser, VCSEL).

[0104] In the embodiment of the present application, the first pulse signal with unstable pulse width output by the controller 10 is converted into a step signal by the first trigger 211, and based on the voltage variation range and rise time of the step signal, the dual comparator 212 is used to output the first drive signal at the first moment, and the second drive signal is output at the second moment after the first moment, so that the laser driver 213 generates a second pulse signal based on the first drive signal and the second drive signal, and the pulse width of the second pulse signal is equal to the time difference between the first moment and the second moment. In the laser emission circuit 21 of the present application, the laser driver 213 drives the laser emitter 214 to emit the outgoing laser based on the second pulse signal, and the pulse width of the second pulse signal is independent of the pulse width of the first pulse signal, and the pulse width of the second pulse signal is fixed. Therefore, the accuracy of the laser emission moment and the laser reception moment received by the time conversion module 23 is high, which effectively improves the measurement accuracy and reliability of the laser ranging device 20.

[0105] Figure 4 This is a circuit principle block diagram of another laser emission circuit and controller provided in an embodiment of the present application. Figure 4 As shown, in a possible embodiment, the laser emission circuit 21 also includes a resetter 215 .

[0106] The first input terminal of the resetter 215 is electrically connected to the first output terminal of the controller 10, the second input terminal of the resetter 215 is electrically connected to the first output terminal of the dual comparator 212, the third input terminal of the resetter 215 is electrically connected to the second output terminal of the dual comparator 212, the first output terminal of the resetter 215 is electrically connected to the second input terminal of the first trigger 211, and the second output terminal and the third output terminal of the resetter 215 are electrically connected to the input terminal of the laser driver 213 respectively.

[0107] The resetter 215 is used to generate a reset signal based on the first pulse signal, and reset the first trigger 211 through the reset signal to stop the laser emitter 214 from working.

[0108] Among them, the first input end of the resetter 215 is electrically connected to the first output end of the controller 10, and is used to receive the first pulse signal from the controller 10; the second input end of the resetter 215 is electrically connected to the first output end of the dual-way comparator 212, and is used to receive the first drive signal and determine whether the first drive signal is valid; the third input end of the resetter 215 is electrically connected to the second output end of the dual-way comparator 212, and is used to receive the second drive signal and determine whether the second drive signal is valid; the first output end of the resetter 215 is electrically connected to the second input end of the first trigger 211, and the resetter 215 is also used to send a reset signal to the first trigger 211 when the reset condition is met, so that the first trigger 211 stops outputting the step signal, so as to interrupt the operation of the dual-way comparator 212, and thereby stop the laser emitter 214 from working.

[0109] It should be noted that by setting the resetter 215, the laser emitter 214 can be controlled to stop working quickly under abnormal circumstances, avoiding thermal damage or other potential dangers caused by excessive emission of laser light, thereby effectively improving the reliability of the laser emission circuit 21.

[0110] In this embodiment, by adding a resetter 215 to the laser emitting circuit 21, the first trigger 211 can be reset and the laser driver 213 can be controlled to stop working, thereby ensuring that the laser emitter 214 can quickly stop emitting the output laser when needed, avoiding safety hazards caused by false triggering or abnormal operation; at the same time, the resetter 215 can accurately control the reset timing by real-time monitoring the first drive signal and the second drive signal output by the dual comparator 212, thereby effectively improving the safety, reliability and control accuracy of the laser ranging device 20.

[0111] like Figure 4 As shown, in a possible embodiment, the resetter 215 includes an inverter 2151 , a second trigger 2152 , a first AND gate 2153 , and a second AND gate 2154 .

[0112] The first input terminal of the inverter 2151 is electrically connected to the first output terminal of the controller 10, the first output terminal of the inverter 2151 is electrically connected to the first input terminal of the second trigger 2152, the output terminal of the second trigger 2152 is electrically connected to the second input terminal of the inverter 2151, and the second output terminal of the inverter 2151 is electrically connected to the second input terminal of the first trigger 211, the second input terminal of the second trigger 2152, the first input terminal of the first AND gate 2153 and the first input terminal of the first AND gate 2153 respectively.

[0113] The second input end of the first AND gate 2153 is electrically connected to the first output end of the dual comparator 212, the second input end of the second AND gate 2154 is electrically connected to the second output end of the dual comparator 212, and the output end of the first AND gate 2153 and the output end of the second AND gate 2154 are electrically connected to the input end of the laser driver 213 respectively.

[0114] It should be noted that the first input end of the inverter 2151 is the first input end of the resetter 215, the second output end of the inverter 2151 is the first output end of the resetter 215, the second input end of the first AND gate 2153 is the second input end of the resetter 215, the second input end of the second AND gate 2154 is the third input end of the resetter 215, the output end of the first AND gate 2153 is the second output end of the resetter 215, and the output end of the second AND gate 2154 is the third output end of the resetter 215.

[0115] The inverter 2151 is used to perform logic inversion on the first pulse signal output by the controller 10 to generate a third pulse signal.

[0116] The second trigger 2152 is used to generate a delay signal based on the third pulse signal.

[0117] It should be noted that the second trigger 2152 uses the rising edge of the third pulse signal as a trigger condition to generate a delay signal synchronized with the third pulse signal. The delay signal can achieve controllable delay through the internal characteristics of the second trigger 2152 (such as clock frequency, delay register settings, etc.).

[0118] In this embodiment, the third pulse signal serves as the clock signal of the second trigger 2152, and can provide a clear trigger clock signal for the second trigger 2152, thereby ensuring that the second trigger 2152 can be triggered with accurate timing to generate a stable delay signal.

[0119] It should be noted that the inverter 2151 is also used to logically invert the delayed signal output by the second trigger 2152 to generate a reset signal, and output it to the second input terminal of the first trigger 211, the second input terminal of the second trigger 2152, the first input terminal of the first AND gate 2153 and the first input terminal of the first AND gate 2153 through the second output terminal of the inverter 2151.

[0120] When the second input terminal of the first trigger 211 receives a reset signal output by the inverter 2151, the reset signal resets the first trigger 211; when the second input terminal of the second trigger 2152 receives a reset signal output by the inverter 2151, the reset signal resets the second trigger 2152.

[0121] The first AND gate 2153 is used to receive the reset signal and the first driving signal, and determine whether to output the first driving signal to the laser driver 213 based on the reset signal and the first driving signal.

[0122] It should be noted that the first AND gate 2153 is used to perform a logical AND operation on the reset signal and the first drive signal. When the reset signal and the first drive signal are both high-level signals, the first AND gate 2153 outputs the first drive signal to the laser driver 213; when the reset signal and / or the first drive signal are low-level signals, the first AND gate 2153 does not output the first drive signal to the laser driver 213, and the laser emitter 214 stops working.

[0123] The second AND gate 2154 is used to receive the reset signal and the second driving signal, and determine whether to output the second driving signal to the laser driver 213 based on the reset signal and the second driving signal.

[0124] It should be noted that the second AND gate 2154 is used to perform a logical AND operation on the reset signal and the second drive signal. When the reset signal and the second drive signal are both high-level signals, the second AND gate 2154 outputs the second drive signal to the laser driver 213; when the reset signal and / or the second drive signal are low-level signals, the second AND gate 2154 does not output the second drive signal to the laser driver 213, and the laser emitter 214 stops working.

[0125] In this embodiment, the reliability of the laser emitting circuit 21 can be effectively improved by providing the first AND gate 2153 and the second AND gate 2154 , and the driving capability of the laser driver 213 can also be enhanced.

[0126] In the embodiment of the present application, the resetter 215 includes an inverter 2151, a second trigger 2152, a first AND gate 2153 and a second AND gate 2154. The feedback design of the inverter 2151 and the second trigger 2152 ensures that the reset signal has a certain delay. The reset signal can control the laser emitter 214 to stop working quickly when the laser emitter 214 is abnormal or the laser emitter 214 needs to stop working, thereby avoiding thermal damage or other potential dangers caused by excessive emission of laser light, and effectively improving the reliability of the laser emission circuit 21. At the same time, the first drive signal and the second drive signal output by the dual comparator 212 are logically controlled by the first AND gate 2153 and the second AND gate 2154 respectively, ensuring that the input signal of the laser driver 213 is activated only when the conditions are met, thereby achieving precise control of the laser emitter 214, and further improving the control accuracy and reliability of the laser ranging device 20.

[0127] Figure 5The circuit principle block diagram of a laser receiving circuit provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, in a possible embodiment, the laser receiving circuit 22 includes a laser receiver 221 , a harmonic suppression circuit 222 , a signal amplifying circuit 223 and a first comparator 224 .

[0128] The output end of the laser receiver 221 is electrically connected to the input end of the harmonic suppression circuit 222, the output end of the harmonic suppression circuit 222 is electrically connected to the input end of the signal amplification circuit 223, the output end of the signal amplification circuit 223 is electrically connected to the first input end of the first comparator 224, the second input end of the first comparator 224 is used to access the first reference voltage, and the output end of the first comparator is electrically connected to the first input end of the time conversion module 23.

[0129] The laser receiver 221 is used to receive the echo laser reflected by the reflecting plate, and convert the optical signal of the echo laser into a first echo signal; the harmonic suppression circuit 222 is used to suppress the high-frequency interference signal in the first echo signal to obtain a second echo signal; the signal amplification circuit 223 is used to amplify the second echo signal to obtain a third echo signal; the first comparator 224 is used to compare the third echo signal with the first reference voltage to obtain a target echo signal, and output the target echo signal to the time conversion module 23.

[0130] The laser receiver 221 is used to convert the received optical signal of the echo laser into an electrical signal (first echo signal) and output it to the harmonic suppression circuit 222 .

[0131] It should be noted that the laser receiver 221 is a photoelectric sensor, and the photoelectric sensor can be a current output type photoelectric sensor or a voltage output type photoelectric sensor. If the photoelectric sensor is a current output type photoelectric sensor, the first echo signal is a current signal; if the photoelectric sensor is a voltage output type photoelectric sensor, the first echo signal is a voltage signal.

[0132] The photoelectric sensor may be a highly sensitive detector, such as an avalanche diode APD (APD), a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), or a combination of the two.

[0133] It should be noted that the echo laser received by the laser receiver 221 is the echo laser processed by the receiving mirror group, and the receiving mirror group performs optical shaping, such as converging and collimating, on the echo laser returned after the outgoing laser is reflected by the surface of the reflector to obtain the optically shaped echo laser, and emits the optically shaped echo laser to the laser receiver 221, and the laser receiver 221 converts the optical signal of the echo laser into an echo signal. Among them, the receiving mirror group can be a focusing mirror group.

[0134] The echo laser refers to the laser received by the laser receiver 221 in one measurement cycle. Ideally, the echo laser refers to the detection echo reflected by the reflector after the outgoing laser is emitted outward and reaches the surface of the reflector. However, since stray light is generated inside the laser ranging device 20, the echo laser received by the laser receiver 221 includes the stray light and the detection echo of the reflector.

[0135] The harmonic suppression circuit 222 is used to suppress the high-frequency interference signal in the first echo signal to obtain the second echo signal.

[0136] It should be noted that the harmonic suppression circuit 222 can filter out high-frequency noise or harmonic components in the first echo signal, and only retain effective signal components (mainly low-frequency or fundamental wave parts) to obtain a second echo signal.

[0137] The harmonic suppression circuit 222 includes a transimpedance amplifier (TIA). A transimpedance amplifier is an amplifier used to convert an input current signal into an output voltage signal. The transimpedance amplifier is widely used in photoelectric receiving systems to process weak current signals output by photoelectric sensors.

[0138] Therefore, the harmonic suppression circuit 222 can also pre-amplify the first echo signal to provide a higher input signal level for the subsequent signal amplification circuit 223 , thereby improving the sensitivity of the laser receiving circuit 22 .

[0139] The signal amplifying circuit 223 is used to amplify the second echo signal to further increase the amplitude of the second echo signal to meet the threshold detection requirement of the first comparator 224 .

[0140] It should be noted that the signal generated after the signal amplification circuit 223 amplifies the second echo signal is the third echo signal.

[0141] The first comparator 224 is used to compare the third echo signal with the first reference voltage to obtain a target echo signal.

[0142] The first reference voltage may be set by the user, and this embodiment does not specifically limit this.

[0143] It should be noted that when the amplitude of the third echo signal exceeds the first reference voltage, the first comparator 224 outputs a high level signal; when the amplitude of the third echo signal does not exceed the first reference voltage, the first comparator 224 outputs a low level signal.

[0144] The target echo signal is a digital pulse signal. The target echo signal changes from a low level to a high level (rising edge trigger) at the moment when the amplitude of the third echo signal exceeds the first reference voltage, forming a precise time mark (laser reception moment), that is, the moment when the laser receiver 221 receives the echo laser.

[0145] Among them, the time conversion module 23 is used to determine the time difference between the laser receiving time and the laser emitting time based on the laser receiving time output by the laser receiving circuit 22 (i.e., the receiving time of the echo laser) and the emission time of the emitted laser by the laser emitting circuit 21 (i.e., the laser emitting time), so that the subsequent controller 10 can determine the distance between the elevator car and the top or bottom of the elevator shaft based on the time difference between the laser receiving time and the laser emitting time.

[0146] In the embodiment of the present application, the laser receiving circuit 22 is formed by a laser receiver 221, a harmonic suppression circuit 222, a signal amplification circuit 223 and a first comparator 224. The laser receiver 221 converts the optical signal of the echo laser into an electrical signal and generates a first echo signal; the harmonic suppression circuit 222 can effectively filter out the high-frequency interference signal in the first echo signal to obtain a second echo signal, which effectively improves the purity and signal-to-noise ratio of the echo signal; the signal amplification circuit 223 further amplifies the second echo signal to obtain a third echo signal to ensure that the amplitude of the third echo signal subsequently input to the first comparator 224 meets the requirements of the first comparator 224; the first comparator 224 accurately compares the third echo signal with the set first reference voltage to generate a target echo signal, and provides the target echo signal to the time conversion module 23, so that the time conversion module 23 can subsequently perform time difference measurement. The laser receiving circuit 22 effectively improves the receiving sensitivity, anti-interference ability and measurement accuracy of the laser ranging device 20, and is suitable for high-precision laser ranging applications in complex environments.

[0147] In a possible embodiment, the third output terminal of the controller 10 is electrically connected to the speed limiter 40 and / or the electronic safety clamp 50 through the control circuit 90 .

[0148] When the actual acceleration measured by the acceleration measuring device 30 is greater than the preset acceleration, the controller 10 controls the speed limiter 40 and / or the electronic safety clamp 50 to operate through the control circuit 90 to stop the elevator car.

[0149] In the case of overspeeding of the elevator car, the controller 10 triggers the speed limiter 40 and / or the electronic safety clamp 50 through the control circuit 90 to limit the running speed of the elevator car to avoid overspeeding of the elevator.

[0150] In an embodiment of the present application, when the acceleration measuring device 30 measures that the elevator car is running overspeed, the controller 10 can trigger the speed limiter 40 and / or the electronic safety clamp 50 through the control circuit 90 to limit the running speed of the elevator car, effectively preventing the elevator car from running overspeed or losing control, and having good safety.

[0151] Figure 6 FIG. 1 is a circuit schematic diagram of a control circuit 90 provided in an embodiment of the present application. Figure 6 As shown, in a possible embodiment, the control circuit 90 includes a first switch tube S1, a first diode D1 and a second diode D2.

[0152] The first switch tube S1 is an NPN transistor or an NMOS tube, a first end of the first switch tube S1 is electrically connected to the third output end of the controller, a second end of the first switch tube S1 is grounded, and a third end of the first switch tube S1 is electrically connected to the first end of the first diode D1.

[0153] The second end of the first diode D1 is electrically connected to the first end of the load device 80 , and the second end of the load device 80 is connected to the input voltage; wherein the load device 80 is a speed limiter 40 or an electronic safety clamp 50 .

[0154] A first end of the second diode D2 is electrically connected to the fourth output end of the controller, and a second end of the second diode D2 is connected to the input voltage.

[0155] The first switch tube S1 is used to control the on or off of the speed limiter 40 or the electronic safety clamp 50 according to the control signal output by the third output terminal of the controller 10 .

[0156] It should be noted that, when the first switch tube S1 is an NPN transistor, the first end of the NPN transistor is the base of the NPN transistor, the second end of the NPN transistor is the emitter of the NPN transistor, and the third end of the NPN transistor is the collector of the NPN transistor. That is, the base of the NPN transistor is electrically connected to the third output terminal of the controller 10, the emitter of the NPN transistor is grounded, and the collector of the NPN transistor is electrically connected to the first end of the external load.

[0157] When the first switch tube S1 is an NMOS tube, the gate of the NMOS tube is the first end of the first switch tube S1, the source of the NMOS tube is the second end of the first switch tube S1, and the drain of the NMOS tube is the third end of the first switch tube S1.

[0158] It should be noted that the first end of the load device 80 is the cathode of the load device 80 , which is electrically connected to the collector of the NPN transistor through the first diode D1 ; the second end of the load device 80 is the anode of the load device 80 , which is connected to the input voltage.

[0159] The first end of the first diode D1 is the cathode of the first diode D1, and the second end of the first diode D1 is the anode of the first diode D1. That is, the cathode of the first diode D1 is electrically connected to the collector of the NPN transistor, and the anode of the first diode D1 is electrically connected to the cathode of the external load.

[0160] The first end of the second diode D2 is the cathode of the second diode D2, and the second end of the second diode D2 is the anode of the second diode D2. That is, the cathode of the second diode D2 is electrically connected to the fourth output terminal of the controller 10, and the anode of the second diode D2 is connected to the input voltage.

[0161] It should be noted that the first diode D1 and the second diode D2 are used to prevent the reverse current from damaging the control circuit 90 .

[0162] Specifically, when the control signal output by the third output terminal of the controller 10 is a low-level signal (the elevator car is operating normally), the base of the NPN transistor has no driving current, the NPN transistor is in a cut-off state, the collector and emitter of the NPN transistor are disconnected, and the circuit where the load device 80 is located is not energized. At this time, the load device 80 (speed limiter 40 or electronic safety clamp 50) is in a non-working state.

[0163] When the control signal outputted from the third output terminal of the controller 10 is a high-level signal (the elevator car is overspeeding), the base of the NPN transistor obtains a driving current, the NPN transistor enters a saturation state, the NPN transistor is turned on, and the circuit where the load device 80 is located is energized. At this time, the load device 80 (speed limiter 40 or electronic safety clamp 50) is in a working state.

[0164] In the embodiment of the present application, the control signal outputted from the third output terminal of the controller 10 is combined with the first switch tube S1 (NPN transistor or NMOS tube) to control the on and off of the load device 80 (speed limiter 40 or electronic safety clamp 50), thereby realizing precise control of the elevator operation state. When the elevator is operating normally, the first switch tube S1 is in the cut-off state, the circuit where the load device 80 is located is disconnected, and the load device 80 does not work; when the elevator is overspeeding, the controller 10 outputs a high-level signal, the first switch tube S1 enters the saturated conduction state, the load device 80 works, and the elevator speed is quickly limited or the elevator is stopped by mechanical braking or applying braking force. In addition, the first diode D1 and the second diode D2 provide effective reverse current protection in the load circuit to prevent the reverse current from damaging the control circuit 90, thereby improving the reliability and anti-interference ability of the control circuit 90.

[0165] Figure 7 FIG. 1 is a circuit diagram of another control circuit provided in an embodiment of the present application. Figure 7 As shown, in a possible embodiment, the control circuit 90 includes a second switch tube S2, a third diode D3 and a fourth diode D4.

[0166] The second switch tube S2 is a PNP transistor or a PMOS tube. The first end of the second switch tube S2 is electrically connected to the third output end of the controller 10, the second end of the second switch tube S2 is electrically connected to the first end of the fourth diode D4, and the third end of the second switch tube S2 is electrically connected to the first end of the third diode D3.

[0167] The second end of the third diode D3 is electrically connected to the first end of the load device 80 , and the second end of the load device 80 is grounded; wherein the load device 80 is a speed limiter 40 or an electronic safety clamp 50 .

[0168] A first end of the fourth diode D4 is also electrically connected to the fourth output end of the controller 10 , and a second end of the fourth diode D4 is connected to the input voltage.

[0169] The second switch tube S2 is used to control the on or off of the load device 80 (speed limiter 40 or electronic safety clamp 50 ) according to the control signal output by the third output terminal of the controller 10 .

[0170] It should be noted that when the second switch tube S2 is a PNP transistor, the base of the PNP transistor is the first end of the second switch tube S2, the emitter of the PNP transistor is the second end of the second switch tube S2, and the collector of the PNP transistor is the third end of the second switch tube S2.

[0171] When the second switch tube S2 is a PMOS tube, the gate of the PMOS tube is the first end of the second switch tube S2, the source of the PMOS tube is the second end of the second switch tube S2, and the source and drain of the PMOS tube are the third end of the second switch tube S2.

[0172] The first end of the third diode D3 is the anode of the third diode D3, and the second end of the third diode D3 is the cathode of the third diode D3. That is, the anode of the third diode D3 is electrically connected to the collector of the PNP transistor, and the cathode of the third diode D3 is electrically connected to the first end of the load device 80.

[0173] The first end of the fourth diode D4 is the cathode of the fourth diode D4, and the second end of the fourth diode D4 is the anode of the fourth diode D4. That is, the cathode of the fourth diode D4 is electrically connected to the emitter of the PNP transistor, and the anode of the fourth diode D4 is connected to the input voltage.

[0174] The first end of the load device 80 is the positive electrode of the load device 80 , which is connected to the negative electrode of the third diode D3 ; the second end of the load device 80 is the negative electrode of the load device 80 , which is grounded.

[0175] It should be noted that the third diode D3 and the fourth diode D4 are used to prevent the reverse current from damaging the control circuit 9090 .

[0176] Specifically, when the control signal output by the third output terminal of the controller 10 is a high-level signal (the elevator car is operating normally), the base of the PNP transistor has no driving current, the PNP transistor is in a cut-off state, the collector and the emitter of the PNP transistor are disconnected, and the circuit where the load device 80 is located is not energized. At this time, the load device 80 (speed limiter 40 or electronic safety clamp 50) is in a non-working state.

[0177] When the control signal outputted from the third output terminal of the controller 10 is a low-level signal (the elevator car is overspeeding), the base of the PNP transistor obtains a driving current, the PNP transistor enters a saturation state, the PNP transistor is turned on, and the circuit where the load device 80 is located is energized. At this time, the load device 80 (speed limiter 40 or electronic safety clamp 50) is in a working state.

[0178] Figure 8 FIG. 1 is a circuit diagram of another control circuit 90 provided in an embodiment of the present application. Figure 8 As shown, in a possible embodiment, the control circuit 90 includes a source relay K1 and a fifth switch tube D5.

[0179] The first input terminal of the source relay K1 is electrically connected to the third output terminal of the controller 10, the second input terminal of the source relay K1 is connected to the input voltage, the first output terminal of the source relay K1 is electrically connected to the first end of the speed limiter 40, the second output terminal of the source relay K1 is electrically connected to the first end of the electronic safety clamp 50, and the second end of the speed limiter 40 and the second end of the electronic safety clamp 50 are both grounded.

[0180] A first end of the fifth switch tube D5 is connected to the input voltage, and a second end of the fifth switch tube D5 is electrically connected to the fourth output end of the controller 10 .

[0181] It should be noted that the source type relay K1 is composed of an electromagnetic coil, a normally open contact and a normally closed contact.

[0182] The first input end of the electromagnetic coil of the source relay K1 is electrically connected to the third output end of the controller 10; the second input end of the electromagnetic coil of the source relay K1 is connected to the input voltage; the normally open contact of the source relay K1 is electrically connected to the first end of the speed limiter 40; the normally closed contact of the source relay K1 is electrically connected to the first end of the electronic safety clamp 50.

[0183] The fifth switch tube D5 is used to suppress the reverse electromotive force generated by the electromagnetic coil of the source relay K1 when the power is off, so as to protect the output end of the controller 10 from high voltage shock.

[0184] Fig. 9 FIG. 1 is a circuit diagram of another control circuit 90 provided in an embodiment of the present application. Fig. 9 As shown, the control circuit 90 includes a leakage relay K2 and a sixth switch tube D6.

[0185] The first input end of the leakage relay K2 is electrically connected to the third output end of the controller 10, the second input end of the leakage relay K2 is grounded, the first output end of the leakage relay K2 is electrically connected to the first end of the speed limiter 40, the second output end of the leakage relay K2 is electrically connected to the first end of the electronic safety clamp 50, and the second end of the speed limiter 40 and the second end of the electronic safety clamp 50 are respectively connected to the input voltage.

[0186] A first end of the sixth switch tube D6 is connected to the input voltage, and a second end of the sixth switch tube D6 is electrically connected to the fourth output end of the controller 10 .

[0187] It should be noted that the leakage type relay K2 is composed of an electromagnetic coil, a normally open contact and a normally closed contact.

[0188] The first input end of the electromagnetic coil of the leakage type relay K2 is electrically connected to the third output end of the controller 10; the second input end of the electromagnetic coil of the leakage type relay K2 is grounded; the normally open contact of the leakage type relay K2 is electrically connected to the first end of the speed limiter 40; the leakage type relay K2 is electrically connected to the first end of the electronic safety clamp 50.

[0189] The sixth switch tube D6 is used to suppress the reverse electromotive force generated by the electromagnetic coil of the leakage type relay K2 when the power is off, so as to protect the output end of the controller 10 from high voltage shock.

[0190] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An elevator shaft absolute value measurement system based on ToF laser ranging technology, characterized in that: The system includes a controller, a laser distance measuring device, an acceleration measuring device, a speed limiter and an electronic safety clamp; The laser distance measuring device is used to measure the distance between the elevator car and the top or bottom of the elevator shaft, and the laser distance measuring device includes a laser transmitting circuit, a laser receiving circuit and a time conversion module; The input end of the laser emitting circuit is electrically connected to the first output end of the controller, the output end of the laser emitting circuit is used to emit an outgoing laser to a reflector, the receiving end of the laser receiving circuit is used to receive an echo laser reflected by the reflector, the output end of the laser receiving circuit is electrically connected to the first input end of the time conversion module, the second input end of the time conversion module is electrically connected to the second output end of the controller, and the output end of the time conversion module is electrically connected to the first input end of the controller; the time conversion module is used to determine the distance between the elevator car and the top or bottom of the elevator shaft based on the emission time of the outgoing laser and the reception time of the echo laser; The acceleration measuring device is installed on the elevator car, the output end of the acceleration measuring device is electrically connected to the second input end of the controller, and the acceleration measuring device is used to measure the actual acceleration of the elevator car and output the actual acceleration of the elevator car to the controller; The speed limiter and the electronic safety clamp are electrically connected to the third output terminal of the controller respectively, and the controller is used to control the speed limiter and / or the electronic safety clamp to operate when the actual acceleration is greater than the preset acceleration, so as to stop the elevator car.

2. The system according to claim 1, characterized in that The laser emission circuit includes a first trigger, a dual-path comparator, a laser driver and a laser emitter; The first input end of the first trigger is electrically connected to the first output end of the controller, the output end of the first trigger is electrically connected to the input end of the dual-way comparator, the first output end and the second output end of the dual-way comparator are electrically connected to the input end of the laser driver respectively, the output end of the laser driver is electrically connected to the input end of the laser emitter, and the output end of the laser emitter is used to emit an outgoing laser to the reflector; The controller is used to output a first pulse signal to the first trigger; The first trigger is used to generate a step signal based on the rising edge of the first pulse signal; the dual comparator is used to generate a first drive signal and a second drive signal based on the step signal, and the first output end of the dual comparator outputs the first drive signal at a first moment, and the second output end of the dual comparator outputs the second drive signal at a second moment, and the second moment is after the first moment; the laser driver is used to generate a second pulse signal based on the first drive signal and the second drive signal, and drive the laser emitter to emit an outgoing laser based on the second pulse signal; wherein the pulse width of the second pulse signal is equal to the time interval between the second moment and the first moment.

3. The system according to claim 2, characterized in that The laser emission circuit also includes a reset device; The first input end of the resetter is electrically connected to the first output end of the controller, the second input end of the resetter is electrically connected to the first output end of the dual comparator, the third input end of the resetter is electrically connected to the second output end of the dual comparator, the first output end of the resetter is electrically connected to the second input end of the first trigger, and the second output end and the third output end of the resetter are electrically connected to the input end of the laser driver respectively; The resetter is used to generate a reset signal based on the first pulse signal, and reset the first trigger through the reset signal to stop the laser emitter from working.

4. The system according to claim 3, characterized in that The resetter includes an inverter, a second trigger, a first AND gate and a second AND gate; The first input end of the inverter is electrically connected to the first output end of the controller, the first output end of the inverter is electrically connected to the first input end of the second trigger, the output end of the second trigger is electrically connected to the second input end of the inverter, and the second output end of the inverter is electrically connected to the second input end of the first trigger, the second input end of the second trigger, the first input end of the first AND gate, and the first input end of the first AND gate respectively; The second input end of the first AND gate is electrically connected to the first output end of the dual comparator, the second input end of the second AND gate is electrically connected to the second output end of the dual comparator, and the output end of the first AND gate and the output end of the second AND gate are electrically connected to the input end of the laser driver respectively.

5. The system according to claim 1, characterized in that The laser receiving circuit includes a laser receiver, a harmonic suppression circuit, a signal amplification circuit and a first comparator; The output end of the laser receiver is electrically connected to the input end of the harmonic suppression circuit, the output end of the harmonic suppression circuit is electrically connected to the input end of the signal amplification circuit, the output end of the signal amplification circuit is electrically connected to the first input end of the first comparator, the second input end of the first comparator is used to access the first reference voltage, and the output end of the first comparator is electrically connected to the first input end of the time conversion module; The laser receiver is used to receive the echo laser reflected by the reflecting plate, and convert the optical signal of the echo laser into a first echo signal; the harmonic suppression circuit is used to suppress the high-frequency interference signal in the first echo signal to obtain a second echo signal; the signal amplification circuit is used to amplify the second echo signal to obtain a third echo signal; the first comparator is used to compare the third echo signal with the first reference voltage to obtain a target echo signal, and output the target echo signal to the time conversion module.

6. The system according to claim 1, characterized in that The third output terminal of the controller is electrically connected to the speed limiter and / or the electronic safety clamp through a control circuit; In the case that the actual acceleration measured by the acceleration measuring device is greater than the preset acceleration, the controller controls the speed limiter and / or the electronic safety clamp to operate through the control circuit to stop the elevator car.

7. The system according to claim 6, characterized in that The control circuit includes a first switch tube, a first diode and a second diode; The first switch tube is an NPN transistor or an NMOS tube, a first end of the first switch tube is electrically connected to the third output end of the controller, a second end of the first switch tube is grounded, and a third end of the first switch tube is electrically connected to the first end of the first diode; The second end of the first diode is electrically connected to the first end of the load device, and the second end of the load device is connected to the input voltage; wherein the load device is the speed limiter or the electronic safety clamp; The first end of the second diode is electrically connected to the fourth output end of the controller, and the second end of the second diode is connected to the input voltage.

8. The system according to claim 6, characterized in that The control circuit includes a second switch tube, a third diode and a fourth diode; The second switch tube is a PNP transistor or a PMOS tube, a first end of the second switch tube is electrically connected to the third output end of the controller, a second end of the second switch tube is electrically connected to the first end of the fourth diode, and a third end of the second switch tube is electrically connected to the first end of the third diode; The second end of the third diode is electrically connected to the first end of the load device, and the second end of the load device is grounded; wherein the load device is the speed limiter or the electronic safety clamp; The first end of the fourth diode is also electrically connected to the fourth output end of the controller, and the second end of the fourth diode is connected to the input voltage.

9. The system according to claim 6, characterized in that The control circuit includes a source relay and a fifth switch tube; The first input end of the source type relay is electrically connected to the third output end of the controller, the second input end of the source type relay is connected to the input voltage, the first output end of the source type relay is electrically connected to the first end of the speed limiter, the second output end of the source type relay is electrically connected to the first end of the electronic safety clamp, and the second end of the speed limiter and the second end of the electronic safety clamp are both grounded; The first end of the fifth switch tube is connected to the input voltage, and the second end of the fifth switch tube is electrically connected to the fourth output end of the controller.

10. The system according to claim 6, characterized in that The control circuit includes a leakage relay and a sixth switch tube; The first input end of the leakage type relay is electrically connected to the third output end of the controller, the second input end of the leakage type relay is grounded, the first output end of the leakage type relay is electrically connected to the first end of the speed limiter, the second output end of the leakage type relay is electrically connected to the first end of the electronic safety clamp, and the second end of the speed limiter and the second end of the electronic safety clamp are respectively connected to the input voltage; The first end of the sixth switch tube is connected to the input voltage, and the second end of the sixth switch tube is electrically connected to the fourth output end of the controller.

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