CN113125183B

CN113125183B - Performance testing device for car accidental movement protection device

Info

Publication number: CN113125183B
Application number: CN202110407603.3A
Authority: CN
Inventors: 姚国龙; 王建新; 马立新; 韩君; 石乐
Original assignee: Ningxia Special Equipment Inspection And Testing Institute
Current assignee: Ningxia Special Equipment Inspection And Testing Institute
Priority date: 2021-04-15
Filing date: 2021-04-15
Publication date: 2023-02-28
Anticipated expiration: 2041-04-15
Also published as: CN113125183A

Abstract

The invention provides a performance testing device of a lift car accidental movement protection device, which comprises an encoder, a single chip microcomputer, differential conversion collector electrode signal modules, D triggers U1-U3, XOR gates U4-U5, a NOT gate U6, AND gates U7-U8 and a counter U9. The invention identifies the error code by comparing the level logics of the phase B signals at the adjacent two jumping edge moments of the phase A pulse of the encoder, generates a frequency multiplication clock signal by directly carrying out XOR on the A, B signals when the error code is generated, filters the error code to recover the normal phase A pulse, provides a reliable counting pulse and improves the reliability of the detection result of the cage accidental movement protection device.

Description

Performance testing device for car accidental movement protection device

Technical Field

The invention relates to the technical field of special equipment inspection, in particular to a performance testing device for a car accidental movement protection device.

Background

The car accidental movement protection device is used for preventing passengers and articles from being injured by the accidental movement of the car when the passengers and the articles get in and out of the elevator car, and the car accidental movement protection device is checked according to the relevant technical specifications, so that the car accidental movement protection device can be effectively guaranteed to exert the protection function, and the accident that the passengers are injured due to the sudden movement of the elevator car under the door opening state of a flat layer is effectively reduced. The performance testing device for the car accidental movement protection device is mainly used for realizing integrated synchronous detection and centralized measurement and analysis of displacement, speed and acceleration in the test process of the car accidental movement protection device, so that inspectors can evaluate the car accidental movement protection device on site in real time.

At present, a performance testing device mostly adopts a high-precision incremental encoder technology and a calculus algorithm, and can simultaneously detect displacement, speed and acceleration real-time data of the operation of an elevator car through real-time detection of a traction steel wire rope. In practical application, the vibration of a code wheel of an encoder or the instability of a rotating shaft can cause output error codes, so that counting errors are caused, and the reliability of the detection result of the protection device for the accidental movement of the car is reduced.

Disclosure of Invention

In view of this, the invention provides a performance testing device for a car accidental movement protection device, so as to solve the problem that the reliability of a detection result is reduced due to an error code output by an encoder of the traditional performance testing device for the car accidental movement protection device.

The technical scheme of the invention is realized as follows: a performance testing device for a car accidental movement protection device comprises an encoder, a single chip microcomputer, a differential conversion collector electrode signal module, D triggers U1-U3, exclusive-OR gates U4-U5, a NOT gate U6, AND gates U7-U8 and a counter U9;

the phase difference signal output end A, B of the encoder is respectively connected with the input end of a differential conversion electrode signal module, the phase A output end of the differential conversion electrode signal module is respectively connected with the second input end of the exclusive-OR gate U4, the D end of the D trigger U1, the CLK end of the D trigger U2 and the CLK end of the D trigger U3 through the NOT gate U6, the phase B output end of the differential conversion electrode signal module is respectively connected with the first input end of the exclusive-OR gate U4, the D end of the D trigger U2 and the D end of the D trigger U3, and the differential conversion electrode signal module is used for converting the differential signal output by the encoder into a collector electrode signal;

the output end of the exclusive-OR gate U4 is connected with the CLK end of the D trigger U1, the Q end of the D trigger U1 is connected with the CLK end of the counter U9, the Q end of the D trigger U2 is connected with the first input end of the exclusive-OR gate U5, the Q end of the D trigger U3 is connected with the second input end of the exclusive-OR gate U5, the output end of the exclusive-OR gate U5 is respectively connected with the second input end of the AND gate U7, the first input end of the AND gate U8 and the enable end of the counter U9, the QN end of the D trigger U2 is connected with the first input end of the AND gate U7, the QN end of the D trigger U3 is connected with the second input end of the AND gate U8, the output end of the AND gate U7 is connected with the AB end of the counter U9, the output end of the AND gate U8 is connected with the BA end of the counter U9, and the DIR end and PLUS _ OUT end of the counter U9 are respectively connected with the single chip microcomputer.

Optionally, the differential conversion collector signal module has a model Q500 or HSZ02DH.

Optionally, the performance testing device for the protection device for accidental movement of the car further comprises a rectifier, a voltage reducer and a voltage stabilizer, and the alternating current input supplies power to each module sequentially through the rectifier, the voltage reducer and the voltage stabilizer.

Optionally, the voltage reducer comprises a switching tube K1, diodes D1 to D4, inductors L1 to L3, and capacitors C1 to C2;

the positive pole of the output end of the rectifier is connected with the voltage stabilizer through a switch tube K1 and an inductor L1 in sequence, the output end of the switch tube K1 is connected with the negative pole of a direct current bus through an inductor L2 and a negative pole of a diode D1 in sequence, the common end of the inductor L2 and the diode D1 is connected with the input end of the switch tube K1 through a forward diode D4, D3 and D2 and an inductor L3 in sequence, the common end of the diode D3 and the D2 is connected with the output end of the switch tube K1 through a capacitor C1, and the common end of the diode D4 and the D3 is connected with the input end of the switch tube K1 through a capacitor C2.

Optionally, the performance testing device for the protection device for accidental movement of the car further comprises a current sampling circuit, a slope compensation circuit, an adder, a voltage sampling circuit, a band gap reference source, an error amplifier, a PWM comparator and a PWM controller;

the input end of the current sampling circuit is connected with the voltage reducer, the output ends of the current sampling circuit and the slope compensation circuit are respectively connected with the input end of the adder, the output end of the adder is connected with the in-phase end of the PWM comparator, and the current sampling circuit is used for collecting current flowing through the inductor L1;

the input end of the voltage sampling circuit is connected with the step-down transformer, the output end of the voltage sampling circuit is connected with the inverting end of the error amplifier, the output end of the band-gap reference source is connected with the inverting end of the error amplifier, the output end of the error amplifier is connected with the inverting end of the PWM comparator, the output end of the PWM comparator is connected with the PWM controller, and a PWM output pin of the PWM controller is connected with the control electrode of the switching tube K1.

Optionally, the slope compensation slope of the slope compensation circuit changes with changes of the input voltage and the output voltage of the voltage reducer.

Optionally, the performance testing device for the protection device against accidental movement of the car further comprises a soft start circuit, wherein an output end of the soft start circuit is connected with a non-inverting end of the error amplifier and used for controlling the output of the bandgap reference source to rise slowly when the voltage reducer is powered on.

Compared with the prior art, the performance testing device for the accidental car movement protection device has the following beneficial effects:

(1) The error code is identified by comparing the level logics of the phase B signals at the adjacent two jumping edge moments of the phase A pulse of the encoder, when the error code is generated, a frequency multiplication clock signal is generated by directly carrying out XOR on the A, B signals, the error code is filtered, the normal phase A pulse is recovered, the reliable counting pulse is provided, and the reliability of the detection result of the cage accidental movement protection device is improved;

(2) When the switching tube K1 is switched on, the current of the buffer inductor L2 cannot change suddenly, so that the rising rate of the current of the switching tube is restrained, and zero current switching-on of the switching tube is realized; when the switch tube K1 is switched off, because the voltage of the buffer capacitor C2 can not change suddenly, the voltage at two ends of the switch tube is clamped at zero, the zero-voltage switching-off of the switch tube is realized, and the buffer element realizes the lossless effect through energy transfer and feedback.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a partial circuit diagram of a performance testing device of an accidental car movement protection device according to the invention;

FIG. 2 is a diagram of A, B phase pulses of an encoder output error of the present invention;

FIG. 3 is a diagram of counting A-phase pulses after eliminating bit errors according to the present invention;

FIG. 4 is a circuit diagram of the voltage reducer of the present invention;

fig. 5 is another circuit diagram of a part of the performance testing device of the protection device for the accidental movement of the car.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, the performance testing device of the protection device for accidental movement of the car in the embodiment includes an encoder, a single chip microcomputer, a differential conversion collector signal module, D flip-flops U1 to U3, xor gates U4 to U5, a not gate U6, and gates U7 to U8, and a counter U9.

The phase difference signal output end A, B of the encoder is respectively connected with the input end of the differential conversion electrode signal module, the phase A output end of the differential conversion electrode signal module is respectively connected with the second input end of the exclusive-OR gate U4, the D end of the D trigger U1, the CLK end of the D trigger U2 and the CLK end of the D trigger U3 through the NOT gate U6, the phase B output end of the differential conversion electrode signal module is respectively connected with the first input end of the exclusive-OR gate U4, the D end of the D trigger U2 and the D end of the D trigger U3, and the differential conversion electrode signal module is used for converting the differential signal output by the encoder into a collector electrode signal.

In this embodiment, the encoder is connected with the gyro wheel through an elastic coupling, and the gyro wheel hugs closely on elevator car haulage rope or overspeed governor during the detection, and when the car sent and moved, the gyro wheel rotated along with wire rope, and the encoder produced pulse signal and inserts the AD interface to the singlechip, and the singlechip is converted pulse signal into digital signal by analog signal to information such as displacement and the speed of car is obtained through calculation processing. In this embodiment, the differential to collector signal module may be selected as Q500 or HSZ02DH, and both are supplied with 24V. The output signal of the encoder is a differential signal that is convenient for long-distance transmission and has high resolution. For example, the encoder outputs 20-bit pulse signals, the single chip microcomputer cannot directly process the pulses, and generally, a pulse sequence is subjected to frequency division by a driver, converted into collector signals and fed back to the single chip microcomputer for processing. The differential conversion collector electrode signal module is used for converting the differential signal output by the encoder into a collector electrode signal.

Generally, as shown in fig. 2, when the encoder outputs an error code, the encoder sequentially generates interference waveforms having widths smaller than half of the normal pulse width at S1 to S4. When jitter occurs, the A, B phase pulses are no longer in a fixed 90 relationship, with pulse widths and periods varying from jitter to jitter.

In this embodiment, as can be seen from the intrinsic structure of the encoder, the A, B phase levels cannot change abruptly at the same time. If the level of the B phase is different, the encoder is considered to output a normal counting pulse signal, the counting end is enabled to count the A phase pulse, and the pulse counting is not influenced by the error code of the B phase; if the level of the B phase is the same, the A phase is considered to have error codes and is not counted. Judging A, B phase relation according to the level of B phase at the rising edge and the falling edge of A phase, if B at the rising edge of A phase is low level, the A phase leads the B phase; if the B phase is low level at the falling edge of the A phase, the B phase leads the A phase. A. The B pulse is different or generates a frequency multiplication pulse as a clock signal of a trigger (rising edge trigger), and the A phase pulse outputs a counting A signal through the trigger. As shown in fig. 1, according to the above analysis, the signals a +, a-, B +, and B-are converted into A, B collector signals by the differential converter electrode signal module, the signal B is xored at the rising edge and the falling edge of the signal a by 2D flip-flops, and the xor result is used as the enable terminal of the counter U9 and matched with two and gates to complete the determination of the A, B phase; A. the signal B is directly XOR-ed to generate a frequency multiplication clock signal, the error code is filtered to recover the normal pulse of the phase A, and reliable counting pulse is provided. The counter U9 is used for controlling the pulse input direction, and the output of the counter U is an encoder rotation direction signal and a counting pulse signal. A and B are collector signals after differential conversion of A1 and A2 and B1 and B2, respectively, and DIR and PUL3E _ OUT are encoder rotation direction and counting pulse output. The encoder can be judged to rotate positively and negatively according to DIR, and when A is ahead of B, DIR is at a low level; DIR is always high when B leads a. And the output of the PUL3E _ OUT is an A-phase waveform after error codes are filtered OUT and is used as a counting pulse. As shown in fig. 3, count a filters out the bit errors in phase a as a count pulse. On the contrary, the same result can be obtained by using phase B as a reference. Therefore, the error code is identified by comparing the level logics of the phase B signals at the adjacent two jumping edges of the phase A pulse of the encoder, when the error code is generated, the frequency multiplication clock signal is generated by directly carrying out XOR on the A, B signals, the error code is filtered, the normal phase A pulse is recovered, the reliable counting pulse is provided, and the reliability of the detection result of the cage accidental movement protection device is improved.

The modules of the present embodiment require external power supply, and particularly the differential conversion collector signal module requires 24V power supply. Thereby the unexpected protection device capability test device that removes of car of this embodiment still includes rectifier, step-down transformer and stabiliser, and alternating current input is to each module power supply through rectifier, step-down transformer and stabiliser in proper order. The 220 alternating current input can output different voltages to supply power to each module through the rectifier, the voltage reducer and the voltage stabilizer in sequence, the voltage reducer is preferably a buck circuit, and the power supply voltage is determined by the duty ratio of the buck circuit. Specifically, as shown in fig. 4, the voltage reducer includes a switching tube K1, diodes D1 to D4, inductors L1 to L3, and capacitors C1 to C2. The positive pole of the output end of the rectifier is connected with the voltage stabilizer through a switch tube K1 and an inductor L1 in sequence, the output end of the switch tube K1 is connected with the negative pole of a direct current bus through an inductor L2 and a negative pole of a diode D1 in sequence, the positive pole of the diode D1 is connected with the negative pole of the direct current bus, the common end of the inductor L2 and the diode D1 is connected with the input end of the switch tube K1 through a forward diode D4, D3 and D2 and an inductor L3 in sequence, the common end of the diode D3 and the common end of the diode D2 are connected with the output end of the switch tube K1 through a capacitor C1, and the common end of the diode D4 and the common end of the diode D3 are connected with the input end of the switch tube K1 through a capacitor C2.

The working process of the voltage reducer in the embodiment is as follows: and at the stage of t0-t1, at the moment of t0, the diode D2 is switched on, the switch tube K1 is switched on, and in the switching-on process, the diode D1 cannot be immediately switched off due to the existence of reverse recovery current. The buffer inductor L2 limits the rising slope di/dt of the current of the switching tube, so that the switching tube realizes zero current switching-on (ZCS), and the stored energy is transmitted to a load. The capacitor C1 discharges through the C1-D2-L3-K1 loop, the stored energy is transferred to the inductor L3, and the current on the inductor L3 slowly rises. At time t1, the current in inductor L2 is 0, and this stage ends. And in the stage from t1 to t2, at the moment of t1, the diode D1 is turned off, the diode D4 is turned on, the capacitor C2 performs resonant discharge with the inductor L2 through the C2-K1-L2-D4 loop, and the stored energy is transmitted to the L2. The capacitor C1 continues to discharge and the current in the inductor L3 continues to rise slowly. At the time t2, the voltage of the capacitor C2 is reduced to-Vs, the current on the inductor L2 reaches a reverse peak value, the currents of the diodes D4 and D3 respectively reach a first forward peak value, the current of the switching tube reaches the first forward peak value, the voltage of the diode D1 reaches a peak value Vin + Vs, and Vin is the output of the rectifier, namely the input of the voltage reducer. At time t2, the voltage of the capacitor C2 is-Vs, and the stage is ended. In the stage t2-t3, at the time t2, the voltage at the two ends of the capacitor C2 is-Vs, the diode D3 is conducted, the inductor L2 transmits the stored energy to the inductor L3 through the L2-D4-D3-D2-K1, and at the time t3, the current on the inductor L2 is reduced to 0. The current on the inductor L3 continues to rise. At time t3, the current of the inductor L2 is 0, and this stage ends. And D3 is turned off in the period from t3 to t 4. The current in the inductor L3 continues to rise slowly. The converter operates in a normal PWM on state at this stage. At the time t4, the switching tube K1 is turned off, and this stage ends, the current flowing through the inductor L3 and the diode D2 reaches the peak value, and the current flowing through the switching tube K1 reaches the second peak value. In the stage t4-t5, at the time t4, the switch tube K1 is turned off, the diode D3 is turned on, and since the voltage across the capacitor C2 is-Vs and cannot change suddenly, the capacitors C2 and C1 clamp the voltage across the switch tube to 0. When the power voltage Vin charges the capacitor C2 through the Vin-C2-D3-C1-Io loop, the voltage at two ends of the switch tube K1 begins to rise, so that the switch tube K1 realizes zero voltage turn-off (ZVS). At the time t5, the voltage across the capacitor C2 and the switch tube reaches the peak value. In the period from t5 to t6, at the time of t5, the capacitor C2 rises to Vin, the diodes D1 and D4 are conducted, and the stored energy is fed back to the power supply through the D1-D4-D3-D2-L3-Vin and the inductor L3. The current source Io charges the capacitor C1 and the inductor L2. At time t5, the current on diodes D1, D4, and D3 peaks. At time t6, the current in inductor L3 is 0, and this stage ends. In the period from t6 to t7, at the time point of t6, the current flowing through the inductor L3 is 0, and the diode D2 is turned off. The current source Io continues to charge the capacitor C1 and the inductor L2. At time t7, the current on the inductor L2 is Io, and this stage is ended. In the period from t7 to t8, at the time of t7, the current of the inductor L2 rises to Io, and the diodes D4 and D3 are turned off. The buck operates in a normal PWM off state at this stage. According to the process, when the switch tube K1 is switched on, the current of the buffer inductor L2 cannot suddenly change, so that the rising rate of the current of the switch tube is restrained, and zero current switching-on of the switch tube is realized. When the switch tube K1 is switched off, because the voltage of the buffer capacitor C2 can not change suddenly, the voltage at two ends of the switch tube is clamped at zero, the zero-voltage switching-off of the switch tube is realized, and the buffer element realizes the lossless effect through energy transfer and feedback.

In this embodiment, in order to improve the control accuracy and the output stability of the voltage reducer, as shown in fig. 5, the performance testing apparatus for the protection device with the preferential accidental movement of the car further includes a current sampling circuit, a slope compensation circuit, an adder, a voltage sampling circuit, a bandgap reference source, an error amplifier, a soft start circuit, a PWM comparator, and a PWM controller. The input end of the current sampling circuit is connected with the voltage reducer, the output ends of the current sampling circuit and the slope compensation circuit are respectively connected with the input end of the adder, the output end of the adder is connected with the in-phase end of the PWM comparator, and the current sampling circuit is used for collecting current flowing through the inductor L1. The input end of the voltage sampling circuit is connected with the step-down transformer, the output end of the voltage sampling circuit is connected with the inverting end of the error amplifier, the output end of the band-gap reference source is connected with the inverting end of the error amplifier, the output end of the error amplifier is connected with the inverting end of the PWM comparator, the output end of the PWM comparator is connected with the PWM controller, and a PWM output pin of the PWM controller is connected with the control electrode of the switching tube K1. The output end of the soft start circuit is connected with the non-inverting end of the error amplifier and used for controlling the output of the band-gap reference source to rise slowly when the voltage reducer is electrified. The slope compensation slope of the slope compensation circuit changes along with the changes of the input voltage and the output voltage of the voltage reducer.

The current sampling circuit samples the inductive current in a certain proportion to obtain a current sampling signal, the current sampling signal and a slope compensation signal are added in a certain mode to obtain a signal, and the signal is transmitted to the positive phase end of the PWM comparator. When the inductor current reaches a predetermined current peak value, the PWM comparator will switch the working state to turn off the main switching tube until the next cycle. The inductor current contains the information of the input voltage, so that when the input voltage suddenly becomes larger or smaller, the rising slope of the inductor current becomes larger or smaller, and the switching tube is turned off early or late. When the duty ratio D of the voltage reducer is larger than 50%, the disturbance of the inductive current can be increased along with the increase of time, subharmonic oscillation of the switching power supply system is caused, and the slope compensation circuit is used for outputting slope voltage to be superposed on the waveform of the inductive current, so that the system is kept stable when the duty ratio D is larger than 50%. In a constant slope compensation circuit, the compensation slope is generally half of the inductor current falling slope, which is the compensation slope required by the system when the maximum duty cycle D = 1. However, such constant large slope compensation ramp is not suitable for all operating states, and in some operating states with small duty ratio, if an excessive compensation ramp is added, the system may generate an overcompensation phenomenon, reduce the loading capacity of the chip, and slow down the transient response of the system. In the embodiment, the slope compensation slope of the slope compensation circuit preferably changes along with the change of the input voltage and the output voltage of the voltage reducer, a dynamic slope compensation voltage which changes along with the input voltage can be generated for slope compensation, and the over-compensation of the system can be avoided to a certain extent on the basis of ensuring the stability of the system.

Generally, in the initial stage of power-on of the voltage reducer, the bandgap reference source quickly establishes and outputs an accurate reference voltage to the non-inverting terminal of the error amplifier, and at the moment, the output voltage is not completely established, so that the feedback voltage divided by the output voltage to the non-inverting terminal of the error amplifier is very small, and the error voltage output by the error amplifier is very large. The error voltage passes through a series of control circuits, so that the switch tube is always in a conducting state. In this embodiment, the soft start circuit controls the output of the bandgap reference source to rise slowly when the voltage reducer is powered on, so that the error voltage output by the error amplifier end at the initial stage of power-on can be prevented from being too large, and the switching tube is prevented from being in a conducting state all the time.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A performance testing device for a car accidental movement protection device comprises an encoder and a single chip microcomputer, and is characterized by further comprising differential conversion collector electrode signal modules, D triggers U1-U3, exclusive-OR gates U4-U5, a NOT gate U6, AND gates U7-U8 and a counter U9;

2. The device for testing the performance of the protection device against accidental car movement of claim 1, wherein the differential to collector signal module is of type Q500 or HSZ02DH.

3. The device for testing the performance of the protection device against accidental movement of the car as recited in claim 1, further comprising a rectifier, a step-down transformer and a voltage stabilizer, wherein an ac input supplies power to each module sequentially through the rectifier, the step-down transformer and the voltage stabilizer.

4. The device for testing the performance of the car accidental movement protection device as claimed in claim 3, wherein the voltage reducer comprises a switching tube K1, diodes D1-D4, inductors L1-L3 and capacitors C1-C2;

the positive pole of the output end of the rectifier is connected with the voltage stabilizer through a switch tube K1 and an inductor L1 in sequence, the output end of the switch tube K1 is connected with the negative pole of a direct current bus through an inductor L2 and a negative pole of a diode D1 in sequence, the positive pole of the diode D1 is connected with the negative pole of the direct current bus, the common end of the inductor L2 and the diode D1 is connected with the input end of the switch tube K1 through a forward diode D4, D3 and D2 and an inductor L3 in sequence, the common end of the diode D3 and the common end of the diode D2 are connected with the output end of the switch tube K1 through a capacitor C1, and the common end of the diode D4 and the common end of the diode D3 are connected with the input end of the switch tube K1 through a capacitor C2.

5. The device for testing the performance of the car accidental movement protection device according to claim 4, further comprising a current sampling circuit, a slope compensation circuit, an adder, a voltage sampling circuit, a band gap reference source, an error amplifier, a PWM comparator and a PWM controller;

6. The device for testing the performance of the car accident movement protection device of claim 5, wherein the slope compensation slope of the slope compensation circuit is changed along with the change of the input voltage and the output voltage of the voltage reducer.

7. The device for testing the performance of the car accident movement protection device as claimed in claim 5, further comprising a soft start circuit, wherein the output end of the soft start circuit is connected with the non-inverting end of the error amplifier and is used for controlling the output of the band-gap reference source to slowly rise when the voltage reducer is powered on.