An elevator brake performance detection device based on no-load test

Abstract

The application discloses an elevator brake performance detection device based on no-load testing, aiming at overcoming the problem of low detection accuracy in the prior art, which comprises a sensor, a control device and a touch screen, the sensor is used for detecting the speed of a traction sheave, the control device is used for judging whether the elevator brake performance is qualified according to the speed of the traction sheave, and the touch screen is used for visually displaying the detection result.

Description

TECHNICAL FIELD

[0001] The present application relates to special equipment detection technology, in particular to an elevator braking performance detection device based on no-load test. BACKGROUND

[0002] The brake of an elevator is one of the important safety components to ensure the normal operation of the elevator and is frequently in action. Whether the elevator can be safely operated is closely related to the working condition of the brake. A large number of accident cases show that one of the main reasons for elevator personal injury accidents is the abnormal braking of the brake, which leads to serious accidents such as shearing, top collision, squatting, car sliding, stop layer out of control and impact.

[0003] At present, an elevator braking performance detection device is used to test whether the elevator brake is abnormal. In actual use, the detection device can detect the braking speed of the car, and judge whether the elevator braking performance is abnormal through the braking speed, which has the advantages of simple test operation and high detection efficiency.

[0004] However, the prior art is not perfect, and there is a large error in the detection and processing of data of the detection device, which leads to a large difference between the final detection result and the actual result. SUMMARY

[0005] In order to overcome the defects and problems of the prior art, the present application provides an elevator braking performance detection device based on no-load test.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] An elevator braking performance detection device based on no-load test comprises:

[0008] a sensor for detecting the speed of the traction sheave;

[0009] a control device for calculating according to the speed of the traction sheave emd and emu , wherein emd is the average deceleration of the car when the empty car runs downward at a normal running speed to the same horizontal position as the counterweight, and emu is the average deceleration of the car when the empty car runs upward at a normal running speed to the same horizontal position as the counterweight; if the elevator has a compensation chain, emd and emu are substituted into the following formula (15) to judge whether the inequality is established:

[0010]

[0011] If not, a detection result of unqualified brake performance of the elevator is generated, if yes, a detection result of qualified brake performance of the elevator is generated, K is a balance coefficient of the elevator;

[0012] A touch screen is electrically connected to the control device for visualizing the detection result;

[0013] The control device comprises a control unit, a charging circuit, a power conversion circuit, a signal conversion and conditioning circuit, a UART-to-USB communication circuit and a data storage module, the sensor is electrically connected to the signal conversion and conditioning circuit, the charging circuit and the power conversion circuit are respectively electrically connected to the lithium battery, the power conversion circuit and the UART-to-USB communication circuit are respectively electrically connected to the touch screen, and the signal conversion and conditioning circuit, the UART-to-USB communication circuit and the data storage module are respectively electrically connected to the control unit.

[0014] Preferably, the control unit comprises a main control chip of model STM32H750VBT6.

[0015] Preferably, the charging circuit comprises a charging management chip, a USB interface, a lithium battery B1, an inductor L1, a capacitor C1, a capacitor C2, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a diode D3, a light-emitting diode D1, a resistor R1 and a resistor R2, the USB interface is electrically connected to the VIN pin of the charging management chip, the lithium battery is electrically connected to the BAT pin of the charging management chip, the inductor L1 is electrically connected to the LX pin of the charging management chip, the inductor L1 is also electrically connected to the USB interface, the capacitor C1 and the capacitor C2 are electrically connected to the VIN pin and the AGND pin of the charging management chip, the diode D3 is electrically connected to the VBS pin of the charging management chip, the diode D3 is also electrically connected to the inductor L1, the capacitor C13, the capacitor C14 and the capacitor C15 are electrically connected to the VBS pin of the charging management chip, the light-emitting diode D1 is electrically connected to the STAT pin of the charging management chip, the resistor R1 is electrically connected between the light-emitting diode D1 and the USB interface, the capacitor C16 and the capacitor C17 are electrically connected to the BAT pin of the charging management chip, and the resistor R2 is electrically connected to the ICHG pin of the charging management chip.

[0016] Preferably, the charging management chip is of model CS5095EA.

[0017] As preferred, the power conversion circuit comprises a DC-DC boost chip, a capacitor C3, a capacitor C4, a voltage dividing resistor R3, a Schottky diode D2, a capacitor C5 and a capacitor C6, the capacitor C3 and the capacitor C4 are electrically connected to the IN pin and the GND pin of the DC-DC boost chip, the voltage dividing resistor R3 is electrically connected to the EN pin of the DC-DC boost chip, the Schottky diode D2 is electrically connected to the SW pin of the DC-DC boost chip, and the capacitor C5 and the capacitor C6 are electrically connected to the SW pin and the FB pin of the DC-DC boost chip.

[0018] As preferred, the DC-DC boost chip is of model MT3608.

[0019] As preferred, the signal conversion conditioning circuit comprises a differential integral amplification circuit and a signal conditioning anti-interference circuit, and the sensor, the differential integral amplification circuit, the signal conditioning anti-interference circuit and the control unit are electrically connected in sequence.

[0020] As preferred, the differential integral amplification circuit comprises a first differential integral amplification circuit and a second differential integral amplification circuit, the first differential integral amplification circuit comprises a differential amplification chip U3A, a CN1-1 input end, a CN1-8 input end, an Ain output end, a matching resistor R10, a matching resistor R14, a matching resistor R8 and a matching resistor R16, the CN1-1 input end and the CN1-8 input end are respectively electrically connected to the sensor, the CN1-1 input end and the CN1-8 input end are arranged on the input end of the differential amplification chip U3A, the Ain output end is arranged on the output end of the differential amplification chip U3A, and the matching resistor R10, the matching resistor R14, the matching resistor R8 and the matching resistor R16 are arranged on the input end of the differential amplification chip U3A, the second differential integral amplification circuit further comprises a differential amplification chip U3B, a CN1-5 input end, a CN1-6 input end, a Bin output end, a matching resistor R11, a matching resistor R15, a matching resistor R9 and a matching resistor R17, the CN1-5 input end and the CN1-6 input end are respectively electrically connected to the sensor, the CN1-5 input end and the CN1-6 input end are arranged on the input end of the differential amplification chip U3B, the Bin output end is arranged on the output end of the differential amplification chip U3B, and the matching resistor R11, the matching resistor R15, the matching resistor R9 and the matching resistor R17 are arranged on the input end of the differential amplification chip U3B.

[0021] As preferred, the signal conditioning anti-interference circuit comprises an A in 1 input end, a B in 3 input end, an A out output end, a B out output end, a comparator U4A, an exclusive-OR gate chip U5A, an inverter U4E, a D flip-flop U6A, a comparator U4B, an exclusive-OR gate chip U5B, an inverter U4D and a D flip-flop U6B, the A in 1 input end is electrically connected to the A in output end, the B in 3 input end is electrically connected to the B in input end, the A out output end and the B out output end are electrically connected to the control unit respectively, the A in 1 input end, the comparator U4A, the exclusive-OR gate chip U5A, the inverter U4E, the D flip-flop U6A and the B out output end are electrically connected in sequence, the B in 3 input end, the comparator U4B, the exclusive-OR gate chip U5B, the inverter U4D, the D flip-flop U6B and the A out output end are electrically connected in sequence, and the CLR pin of the D flip-flop U6B is electrically connected to the PRE pin of the D flip-flop U6A.

[0022] As preferred, the model of the differential amplification chip is TL3472.

[0023] As preferred, the UART-to-USB communication circuit comprises a communication chip and two serial-to-USB interfaces arranged on the communication chip, and the model of the communication chip is CH340K.

[0024] As preferred, the sensor comprises a rotary encoder.

[0025] As preferred, the sensor comprises a rotary transformer.

[0026] As preferred, the sensor comprises a rotary transformer, the rotary transformer comprises a stator and a rotor rotatably arranged on the stator, and an air gap is left between the rotor and the stator.

[0027] As preferred, the acceleration a of the car can be calculated by the following formula:

[0028] a = (S1-0) / (t2-t1),

[0029] wherein a is the acceleration of the car, S1 is the actual speed during the uniform speed movement of the car, t1 is the time when the car starts to decelerate detected by the timer in the control device, and t2 is the time when the car stops detected by the timer in the control device.

[0030] The present application has the following prominent and beneficial technical effects compared with the prior art:

[0031] Compared with the traditional elevator brake performance testing device, the application does not need to load the heavy object in the car or load the flywheel set on the motor, simplifies the devices and steps required for elevator brake performance testing, and therefore has the advantages of simple operation, time and labor saving in detection, and low detection cost.

[0032] In the application, through test experiments, although the application omits loading the heavy object in the car or loading the flywheel set on the motor, the load detection of loading the heavy object in the car or loading the flywheel set on the motor can be simulated, and the detection result is basically consistent with the actual result, and therefore the application has the advantages of accurate detection and high authenticity.

[0033] In the application, the transmission device collects the speed data on the traction sheave, avoids the problems of detection error caused by the shaking of the car in motion and the slippage between the steel wire rope and the traction sheave, and therefore further improves the detection accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic diagram of the elevator of the application;

[0035] Figure 2 is a structural schematic diagram of the traction machine of the application;

[0036] Figure 3 is a structural schematic diagram of the rotary encoder of the application;

[0037] Figure 4 is a structural schematic diagram of the control device of the application;

[0038] Figure 5 is a circuit principle diagram of the charging circuit of the application;

[0039] Figure 6 is a circuit principle diagram of the power conversion circuit of the application;

[0040] Figure 7 is a circuit principle diagram of the differential integral amplification circuit of the application;

[0041] Figure 8 is a circuit principle diagram of the signal conditioning anti-interference circuit of the application;

[0042] Figure 9 is a circuit principle diagram of the UART to USB communication circuit of the application;

[0043] Figure 10 is a structural schematic diagram of the rotary transformer of the application;

[0044] Figure 11 is an internal structural schematic diagram of the rotary transformer of the application;

[0045] Figure 12 is a circuit schematic diagram of the rotor winding and the stator winding of the resolver of the present application;

[0046] Figure 13 is a waveform diagram of the output voltage of the winding on the rotor in the resolver of the present application;

[0047] Figure 14 is a schematic diagram of the control device of the present application converting the output voltage signal of the sine waveform into the output voltage signal of the square waveform;

[0048] Figure 15 is a circuit schematic diagram of the brake control circuit of the present application;

[0049] In the figure: 11 - car, 12 - hoisting machine, 13 - counterweight device, 14 - traveling cable, 15 - compensating chain, 121 - motor, 122 - brake, 123 - traction sheave, 124 - hoisting rope, 31 - control unit, 32 - charging circuit, 33 - power conversion circuit, 34 - signal conversion and conditioning circuit, 35 - UART-to-USB communication circuit, 36 - data storage module, 37 - sensor, 38 - touch screen, 41 - rotating shaft, 42 - retaining ring, 43 - machine housing, 44 - stator, 45 - rotor, 46 - corrugated washer, 47 - retaining ring, 48 - collector ring, 49 - brush, 50 - terminal post. DETAILED DESCRIPTION

[0050] For the convenience of those skilled in the art, the present application will be further described below in conjunction with the drawings and specific embodiments.

[0051] As Figures 1 to 13 shown, the embodiment discloses an elevator brake performance detection device based on no-load test, for testing the brake performance of the elevator, comprising a sensor, a control device and a touch screen.

[0052] The control device is used to calculate α emd and α emu , wherein α emd is the average deceleration of the car when the no-load car runs downward at the normal running speed to the same horizontal position as the counterweight and brakes, and α emu is the average deceleration of the car when the no-load car runs upward at the normal running speed to the same horizontal position as the counterweight and brakes; if the elevator has a compensating chain, then α emd and α emu are substituted into the following equations (14) and (15) to determine whether both inequalities are established:

[0053]

[0054]

[0055] If not, a detection result of elevator braking performance unqualified is generated, if yes, a detection result of elevator braking performance qualified is generated, K is the balance coefficient of the elevator.

[0056] If the elevator has no compensation chain, then emd and emu Substitute the following formula (16) and (17) to determine whether both inequalities are established:

[0057]

[0058]

[0059] If not, a detection result of elevator braking performance unqualified is generated, if yes, a detection result of elevator braking performance qualified is generated, K is the balance coefficient of the elevator.

[0060] Elevator

[0061] As shown in the figure, in the embodiment, the elevator refers to a traction drive elevator, which is a fixed type lifting device serving a specified floor. Figure 1 The elevator comprises a car, which is arranged in a shaft, and at least two vertical or inclined rigid tracks with an inclination less than 15° are installed in the shaft, and the car runs between the rigid tracks. The size and structure of the car are convenient for passengers to enter or exit or for loading goods.

[0062] As shown in the figure, the elevator further comprises a traction machine, which comprises a motor, a brake and a traction wheel, and is arranged in the shaft. The motor is used to drive the traction wheel to rotate. In actual use, the motor drives the traction wheel, and the traction wheel drives the car to ascend or descend in the shaft through the traction rope. The brake is used to brake the traction wheel, so as to slow down and stop the car. The motor and the brake are arranged on both sides of the traction wheel and are respectively connected to the traction wheel. The brake comprises a brake wheel and a brake shaft. The traction rope is a transmission medium between the traction wheel and the car, and is arranged in the wheel groove of the traction wheel. The car is hung on the traction rope.

[0063] Figure 2 The elevator further comprises a counterweight device, which is used to balance the weight of the car, so as to reduce the consumption of energy and the loss of motor power. The counterweight device is also connected to the traction rope. The traction wheel only needs to drive the difference between the weight of the car and the weight of the counterweight device, so that the car can move up and down in the shaft.

[0064] The elevator further comprises a counterweight device, which is used to balance the weight of the car, so as to reduce the consumption of energy and the loss of motor power. The counterweight device is also connected to the traction rope. The traction wheel only needs to drive the difference between the weight of the car and the weight of the counterweight device, so that the car can move up and down in the shaft.

[0065] ​The elevator further comprises a traveling cable, which is a cable for supplying power to the elevator and generally comprises an elevator power cable and an emergency power cable. The traveling cable extends from one side of the hoistway into the car, and is used to ensure normal control, communication, lighting, ventilation, etc. of the car.

[0066] In some elevators, a compensation chain is not included, while in other elevators, the compensation chain is further included, which is connected between the car and the counterweight device, and the car, the traction sheave, the counterweight device and the compensation chain form a closed loop structure, and the compensation chain is used to balance the weight of the traction rope and balance the operation of the car.

[0067] Sensor

[0068] In the present application, the sensor is used to detect the speed of the traction sheave. The conventional sensor is used to directly detect the speed of the car, but in actual use, it is found that the car will produce a certain amount of jitter due to movement, and a slight degree of slip phenomenon will occur between the traction rope and the traction sheave during braking (the slip phenomenon of the car at different operating speeds is different), which will cause a certain degree of error in the data collected by the sensor. Therefore, the sensor is arranged on the traction sheave in the present application, which is used to collect the speed of the traction sheave, thereby avoiding the error caused by the above-mentioned phenomenon, and thereby improving the accuracy of detection.

[0069] As shown in Figure 3 , the sensor comprises a rotary encoder, which is used to measure the angular displacement and angular velocity of the traction sheave, and convert the mechanical quantity into a corresponding electrical pulse signal output to the control device. The rotary encoder is electrically connected to the control device and is installed on the traction sheave. In actual use, the rotary encoder can generate high-speed pulse signals in real time and provide them to the control device to calculate the speed of the car.

[0070] As shown in Figure 4 , in another embodiment, the sensor comprises a rotary transformer, which can be used to measure the speed of the traction sheave, and thereby obtain the speed and acceleration of the car. The rotary transformer can be arranged on the traction sheave. The rotary transformer is a contact type rotary transformer, which specifically comprises a rotating shaft, a retaining ring, a housing, a stator, a rotor, a corrugated washer, a retaining ring, a collector ring, a brush and a terminal post. The stator and the rotor are both provided with windings.

[0071] The rotary transformer is a signal element whose output voltage of the winding on the rotor changes with the rotation angle of the rotor. In actual use, after an alternating voltage is applied to the winding on the stator, the winding on the rotor generates an output voltage due to the change of the cross-link magnetic flux. The coupling coefficient of the output voltage changes with the angle of the rotor. Therefore, according to the measured output voltage of the winding on the rotor, the size of the rotation angle of the rotor can be known.

[0072] As shown in the figure, the car is in an empty state, i.e. the windings on the rotor and the windings on the stator form an open circuit, only the AC is applied to the position of the windings D1-D2 on the stator, and there is an air gap between the stator and the rotor, the pulsating magnetic density will be generated in the air gap, and the axis of the pulsating magnetic density is located on the axis of the windings on the stator. According to the electromagnetic theory of the rotary transformer, the rotary transformer potential will be induced on the windings of the rotor, i.e. the output voltage is generated on the windings of the rotor. The windings on the rotor include the cosine output windings Z1-Z2 and the sine output windings Z3-Z4. The induced potential on the cosine output windings Z1-Z2 is:

[0073] E R1 = E R cosθ (2-1),

[0074] wherein E R1 is the induced potential on the cosine output windings Z1-Z2, E R is the induced potential of the magnetic flux ΦD of the rotary transformer on the windings of the rotor when the axis of the windings of the rotor coincides with the axis of the windings of the stator, and θ is the electrical angle of the rotary transformer.

[0075] The induced potential on the sine output windings Z3-Z4 is expressed by the following formula:

[0076] E R2 = E R cos(θ+90°) = -E R sinθ (2-2),

[0077] wherein E R2 is the induced potential on the sine output windings Z3-Z4.

[0078] The induced potential at the windings D1-D2 on the stator is expressed by E D , then the transformation ratio on the rotary transformer is:

[0079]

[0080] wherein k u is the transformation ratio on the rotary transformer, W R is the effective number of turns of the windings on the rotor, and W D is the effective number of turns of the windings on the stator.

[0081] The following formula is derived from the formulas (2-1) to (2-3):

[0082] E R1 = k u E D cosθ (2-4)

[0083] E R2 = -ku E D sinθ (2-5)

[0084] The potential of the stator winding when the car is empty is equal to the output voltage, i.e. E D = U f1 , so that equations (2-4) and (2-5) can be written as:

[0085] U R1 = k u U f1 cosθ (2-6)

[0086] U R2 = -k u U f1 sinθ (2-7)

[0087] where U R1 is the induced voltage on the cosine output winding Z1-Z2, U R2 is the induced voltage on the sine output winding Z3-Z4, and U f1 is the output voltage of the rotor winding.

[0088] As shown in the figure, it is the waveform diagram of the output voltage of the rotor winding in the rotary transformer. The control device can be electrically connected to the rotary transformer, as shown in the figure, the output voltage generated by the rotor winding can be input to the control device, the signal conversion conditioning circuit in the control device can convert the output voltage signal of the sine waveform into the output voltage signal of the square waveform, and then the time width T of each pulse generated by the square waveform voltage signal is recorded according to the timer set in the control device, and the speed of the traction sheave is calculated.

[0089] If the elevator starts, the car will reach a uniform movement process after experiencing an acceleration process, and the uniform movement process of the car includes the process of the car moving upward at a uniform speed and / or the process of the car moving downward at a uniform speed. In the process of the car moving at a uniform speed, the timer in the control device records the time width of each pulse generated by the square waveform voltage signal, and the time width of each pulse is consistent, which can be recorded as T1, T2, … Tn respectively, and T1 = T2… = Tn, T1 represents the time width of the first pulse, T2 represents the time width of the second pulse, and Tn represents the time width of the nth pulse, n is a positive integer. Therefore, the speed in the process of the car moving at a uniform speed can be calculated by the following formula:

[0090] S1 = k * (1 / Tn) * 60 rpm (2-8)

[0091] Wherein, S1 is the actual speed in the process of the car moving at a constant speed, k is the conversion coefficient between the actual speed of the car and the speed of the traction sheave measured by the rotary transformer, rpm is the number of rotations of the rotor per minute of the rotary transformer. The timer of the control device monitors the time width of each pulse in real time.

[0092] As shown in the figure, the control device further comprises a brake control circuit, which is arranged between the control device and the brake, and the brake control circuit comprises a resistor R1, a diode D1, a capacitor C1, an optical coupling chip, a capacitor C2 and a resistor R2. In actual use, the control device sends a low-voltage brake signal to the brake control circuit, and the brake signal is amplified by the brake control circuit to generate a brake amplification signal for controlling the brake, and the brake receives the brake amplification signal to brake the elevator, so that the car starts to decelerate until it stops. If the time width of the pulse at the current time detected by the timer is greater than the time width of the pulse at the last time, it indicates that the car starts to decelerate, and the timer records the time when the car starts to decelerate as t1 and the time when the car stops as t2, then the acceleration a of the car during deceleration is calculated by the following formula:

[0093] a = (S1-0) / (t2-t1).

[0094] Control device

[0095] As Figure 4 shown in the figure, in the present application, the control device is used to generate a detection result according to the rotational speed of the traction sheave, and the detection result comprises a detection result of unqualified brake performance of the elevator and a detection result of qualified brake performance of the elevator.

[0096] In actual use, the control device obtains the rotational speed of the traction sheave; then calculates α emd and α emu according to the rotational speed of the traction sheave, wherein α emd is the average deceleration of the car when the empty car runs downward at a normal running speed to the same horizontal position as the counterweight, and α emu is the average deceleration of the car when the empty car runs upward at a normal running speed to the same horizontal position as the counterweight; if the elevator has a compensating chain, then α emd and α emu are substituted into the following formulas (14) and (15) to determine whether both inequalities are established:

[0097]

[0098]

[0099] If not, the control device generates a detection result of elevator braking performance unqualified, if yes, it will generate a detection result of elevator braking performance qualified, K is the balance coefficient of the elevator, for most elevators, the value of K is between 0.4 and 0.5.

[0100] The control device comprises a control unit, a charging circuit, a power conversion circuit, a signal conversion and conditioning circuit, a UART-to-USB communication circuit and a data storage module. The sensor is electrically connected to the signal conversion and conditioning circuit. The charging circuit and the power conversion circuit are respectively electrically connected to the lithium battery. The power conversion circuit and the UART-to-USB communication circuit are respectively electrically connected to the touch screen. The signal conversion and conditioning circuit, the UART-to-USB communication circuit and the data storage module are respectively electrically connected to the control unit. The lithium battery can be connected to the control unit through an MCU power module (not shown in the figure). The MCU power module is used to convert the voltage of the lithium battery into a voltage suitable for the control unit.

[0101] The control unit, also known as the MCU circuit, is the core device of the entire control device, and plays a role in signal data processing, control and interaction. It comprises a main control chip with model number STM32H750VBT6. The main control chip is based on ARM Cortex M7 architecture, and is equipped with resources such as ADC, FLASH, UART and up to 10 Timers on the main control chip, which simplifies program design and meets the special needs of multi-channel Timers. And its peripheral circuit is composed of external crystal oscillator clock circuit, reset circuit, SWD program burning circuit and storage circuit, etc.

[0102] As shown in Figure 5 The charging circuit is used to convert external power and charge the lithium battery, and comprises a charging management chip. The charging management chip has a model number of CS5095EA, and is represented by a symbol U1. It is a chip with an input voltage of 5V, a maximum charging current of 1.2A, a integrated power MOS tube and an asynchronous switching structure. The charging management chip only needs a few peripheral devices when applied in the charging circuit, effectively reducing the overall scheme size, and can adaptively adjust the input current to match various adapters and meet the use conditions of the control device. The charging circuit further comprises a USB interface. The USB interface is electrically connected to the VIN pin of the charging management chip. The USB interface is represented by a symbol CON1, and the standard of the USB interface is Mini-B. In actual use, a USB line can be plugged into the USB interface. The USB line can be electrically connected to an external power supply. The external power supply supplies power through the USB interface. The charging circuit further comprises a lithium battery B1. The lithium battery B1 is electrically connected to the BAT pin of the charging management chip.

[0103] The charging circuit includes an inductor L1, a capacitor C1, a capacitor C2, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a diode D3, a light emitting diode D1, a resistor R1 and a resistor R2, the inductor L1 is electrically connected to the LX pin of the charging management chip, the inductor L1 is also electrically connected to the USB interface, the capacitor C1 and the capacitor C2 are electrically connected to the VIN pin and the AGND pin of the charging management chip, the diode D3 is electrically connected to the VBS pin of the charging management chip, the diode D3 is also electrically connected to the inductor L1, the capacitor C13, the capacitor C14 and the capacitor C15 are electrically connected to the VBS pin of the charging management chip, the light emitting diode D1 is electrically connected to the STAT pin of the charging management chip, the resistor R1 is electrically connected between the light emitting diode D1 and the USB interface, the capacitor C16 and the capacitor C17 are electrically connected to the BAT pin of the charging management chip, and the resistor R2 is electrically connected to the ICHG pin of the charging management chip.

[0104] As shown in Figure 6 The power conversion circuit is used for converting the voltage output by the lithium battery into a 24V voltage. The power conversion circuit includes a DC-DC boost chip, the model of the DC-DC boost chip is MT3608, has the functions of under-voltage lockout, current limit and over-temperature overload protection, and can well cope with the working abnormality of the control device. The power conversion circuit can be electrically connected between the lithium battery and the touch screen. In actual use, the output voltage of the lithium battery is 9-12.6V, and the power conversion circuit stably converts the output voltage of the lithium battery into an output voltage of 24V. The power conversion circuit further includes a capacitor C3 and a capacitor C4, the capacitor C3 and the capacitor C4 constitute a filter circuit, and the capacitor C3 and the capacitor C4 are electrically connected to the IN pin and the GND pin of the DC-DC boost chip. In actual use, the capacitor C3 and the capacitor C4 are used for filtering the power input into the DC-DC boost chip. The power conversion circuit further includes a voltage dividing resistor R3, the voltage dividing resistor R3 is electrically connected to the EN pin of the DC-DC boost chip. In actual use, the power is input into the EN pin of the DC-DC boost chip through the voltage dividing resistor R3, and the voltage dividing resistor R3 plays a role of voltage division and has an over-voltage protection effect on the DC-DC boost chip. The power conversion circuit further includes a Schottky diode D2, the Schottky diode is electrically connected to the SW pin of the DC-DC boost chip. In actual use, the Schottky diode D2 rectifies the power output by the DC-DC boost chip. The power conversion circuit further includes a capacitor C5 and a capacitor C6, the capacitor C5 and the capacitor C6 also constitute a filter circuit, and the capacitor C5 and the capacitor C6 are electrically connected to the SW pin and the FB pin of the DC-DC boost chip. In actual use, the capacitor C5 and the capacitor C6 filter the power output by the DC-DC boost chip.

[0105] As shown in Figure 7As shown, the signal conversion conditioning circuit includes a differential integral amplification circuit. The sensor is electrically connected to the differential integral amplification circuit, which is used to amplify the differential mode signal but suppress the common mode signal. The differential integral amplification circuit includes a first differential integral amplification circuit and a second differential integral amplification circuit, which are respectively electrically connected to the sensor, and the circuit structures of the first differential integral amplification circuit and the second differential integral amplification circuit are consistent, thereby realizing the effects of signal negative feedback and amplification. The first differential integral amplification circuit includes a differential amplification chip U3A, and the model of the differential amplification chip U3A is TL3472. The first differential integral amplification circuit includes a CN1-1 input end, a CN1-8 input end, and an A in output end, the CN1-1 input end and the CN1-8 input end are respectively electrically connected to the sensor, the CN1-1 input end and the CN1-8 input end are arranged on the input end of the differential amplification chip U3A, and the A in output end is arranged on the output end of the differential amplification chip U3A, thereby forming a circuit structure of double-ended input and single-ended output, and realizing the effect of suppressing common mode interference. The first differential integral amplification circuit further includes a matching resistor R10, a matching resistor R14, a matching resistor R8, and a matching resistor R16. The matching resistor R10, the matching resistor R14, the matching resistor R8, and the matching resistor R16 are arranged on the input end of the differential amplification chip U3A, and in actual use, the matching resistor R10, the matching resistor R14, the matching resistor R8, and the matching resistor R16 are used to improve the transmission capability of the sensor signal on the first differential integral amplification circuit.

[0106] The second differential integral amplification circuit further includes a differential amplification chip U3B, and the model of the differential amplification chip U3B is TL3472. The first differential integral amplification circuit includes a CN1-5 input end, a CN1-6 input end, and a B in output end, the CN1-5 input end and the CN1-6 input end are respectively electrically connected to the sensor, the CN1-5 input end and the CN1-6 input end are arranged on the input end of the differential amplification chip U3B, and the B in output end is arranged on the output end of the differential amplification chip U3B, thereby forming a circuit structure of double-ended input and single-ended output, and realizing the effect of suppressing common mode interference. The first differential integral amplification circuit further includes a matching resistor R11, a matching resistor R15, a matching resistor R9, and a matching resistor R17. The matching resistor R11, the matching resistor R15, the matching resistor R9, and the matching resistor R17 are arranged on the input end of the differential amplification chip U3B, and in actual use, the matching resistor R11, the matching resistor R15, the matching resistor R9, and the matching resistor R17 are used to improve the transmission capability of the sensor signal on the first differential integral amplification circuit. In actual use, the first differential integral amplification circuit and the second differential integral amplification circuit are used to convert the signal from a sine wave to a square wave.

[0107] As Figure 8 The signal conversion conditioning circuit further comprises a signal conditioning anti-interference circuit, which is used for eliminating conducted interference and radiation, and is used for conditioning the sensor output signal to eliminate error signals and common mode noise and even harmonics. Due to the high-power motion control environment of the elevator, the electronic devices such as the switching power supply and the power module of the elevator are prone to generate strong conducted interference and radiation, and the electronic devices such as the transmission line and the motor of the elevator are also prone to generate strong radiation interference. These interferences are prone to have a certain influence on the sensor signal transmission, thereby causing pulse counting errors and even destroying the stability of the detection device. Therefore, the signal conditioning anti-interference circuit is adopted to solve the problem that the sensor signal is prone to interference.

[0108] The signal conditioning anti-interference circuit comprises an A in 1 input end and a B in 3 input end, the A in 1 input end is electrically connected to the A in output end, and the B in 3 input end is electrically connected to the B in output end. The signal conditioning anti-interference circuit further comprises an A out output end and a B out output end, the A out output end and the B out output end are electrically connected to the control unit respectively. The signal conditioning anti-interference circuit further comprises a comparator U4A, an exclusive OR gate chip U5A, an inverter U4E and a D flip-flop U6A, the A in 1 input end, the comparator U4A, the exclusive OR gate chip U5A, the inverter U4E, the D flip-flop U6A and the B out output end are electrically connected in sequence. The signal conditioning anti-interference circuit further comprises a comparator U4B, an exclusive OR gate chip U5B, an inverter U4D and a D flip-flop U6B, the B in 3 input end, the comparator U4B, the exclusive OR gate chip U5B, the inverter U4D, the D flip-flop U6B and the A out output end are electrically connected in sequence, and a CLR pin of the D flip-flop U6B is electrically connected to a PRE pin of the D flip-flop U6A. The models of the comparator U4A and the comparator U4B are both 74HC14, and the hysteresis interval of the comparator U4A and the comparator U4B is used to suppress small disturbances near the comparison point. The models of the exclusive OR gate chip U5A and the exclusive OR gate chip U5B are both 74HC86. The models of the inverter U4E and the inverter U4D are both 74HC14. The models of the D flip-flop U6A and the D flip-flop U6B are both 74HC74, and the D flip-flop U6A and the D flip-flop U6B adopt staggered triggering to ensure that the sensor signal is located in the most stable region output, which can well suppress large amplitude jitter and peak interference. In actual use, when the sensor signal is subjected to differential conditioning, it successively passes through the comparator U4A, the exclusive OR gate chip U5A, the inverter U4E, the D flip-flop U6A, and the comparator U4B, the exclusive OR gate chip U5B, the inverter U4D and the D flip-flop U6B to generate a square wave signal, the formation of the square wave signal adopts the staggered triggering mode of the D flip-flop U6A and the D flip-flop U6B to ensure that the signal is output at the most stable time, avoiding the output of interference signals at the transition edge of the square wave signal. The signal conditioning anti-interference circuit further comprises a resistor R20 and a capacitor C30, the resistor R20 and the capacitor C30 constitute an RC parallel circuit, the resistor R20 and the capacitor C30 are arranged between the comparator U4A and the exclusive OR gate chip U5A, and the resistor R20 and the capacitor C30 play a filtering role. The signal conditioning anti-interference circuit further comprises a resistor R22 and a capacitor C31, the resistor R22 and the capacitor C31 also constitute an RC parallel circuit, the resistor R22 and the capacitor C31 are arranged between the comparator U4B and the exclusive OR gate chip U5B, and the resistor R22 and the capacitor C31 also play a filtering role. The signal conditioning anti-interference circuit further comprises a resistor R21, the resistor R21 is arranged between the inverter U4E and the D flip-flop U6A, and the resistor R21 plays a voltage dividing role.The signal conditioning interference circuit further comprises a resistor R23, which is arranged between the inverter U4D and the D flip-flop U6B and functions as a voltage divider.

[0109] In actual use, the output end of the comparator U4A is provided with an inverter U4E, which is specifically a non-inverting Schmitt trigger, and the type of the inverter U4E is also 74HC14. The inverter U4E inversely shapes the output square wave, and the shaped square wave is output as another phase square wave. Since the comparison point voltage of the comparator U4A is applied to the non-inverting terminal of the control unit, the high level of the square wave output by the comparator U4A after inversion corresponds to the positive level range of the control unit. At the non-jump edge of the output signal of the comparator U4A, the inverter U4E output remains at a high level, and the D flip-flop U6A maintains the output of the previous moment. When the square wave signal jumps, the input of the XOR gate chip U5A does not have a sudden change in level due to the presence of the RC parallel circuit, and the XOR gate chip U5A becomes a low level after being inverted by the inverter U4E, thereby triggering the level state of the output of the D flip-flop U6A. Since the capacitor on the XOR gate chip U5A discharges relatively quickly, the XOR gate chip U5A and the inverter U4E generate a falling edge pulse signal. Similarly, the comparator U4B, the XOR gate chip U5B, the inverter U4D, and the D flip-flop U6B are used in the same way, so that the sensor signal output corresponding square wave signal to the control unit when passing through the signal conditioning interference circuit, and the high and low levels are converted.

[0110] As shown in Figure 9 The UART-to-USB communication circuit comprises a communication chip and two serial-to-USB interfaces arranged on the communication chip. The type of the communication chip is CH340K, and the communication chip is denoted by symbol U8. The two serial-to-USB interfaces are denoted by symbols MCU TXD1 and MCU RXD1, respectively. The communication chip has a built-in clock generator without external crystal oscillator and oscillation capacitor, and has a built-in independent receive and transmit buffer. The communication chip supports simplex, half-duplex or full-duplex asynchronous serial communication, and the maximum speed is 2Mb / S. Under the Windows operating system of a computer, the driver program of the communication chip can simulate a standard serial port, and can be compatible with most original serial port application programs, and usually does not need to be modified to meet the requirements of the communication circuit in the system. One serial-to-USB interface realizes communication between the control unit and the touch screen, so that the control unit can visually display the detection results on the touch screen, and the user can also set parameters in the control unit through the touch screen. The other serial-to-USB interface is used to realize the external computer of the control unit, so that the detection results can be uploaded to the computer.

[0111] Method for testing the braking performance of an elevator

[0112] In the Elevator Supervision and Periodic Inspection Rules - Traction and Force Drive Elevators (TSG T7001-2009 including the first and second amendment), it is mentioned that the braking test requirement is that the car is loaded with 125% of the rated load, and when the car is descending at the normal operating speed, the power supply of the motor and the brake is cut off, the brake should be able to stop the drive machine, and after the test, the car should not be deformed and damaged.

[0113] The traditional elevator braking performance detection method usually needs to load heavy objects (125% of the rated load) in the car or load flywheel sets on the motor to simulate the way of loading heavy objects in the car to ensure the accuracy of detection. However, the traditional detection method needs to use heavy objects or flywheel sets, which leads to the problems of high detection cost and complicated detection operation.

[0114] Therefore, the present application hopes to detect the braking performance of the elevator without loading heavy objects in the car or loading flywheel sets on the motor, and also meets the requirements of the braking test and ensures the accuracy of the braking performance detection.

[0115] Therefore, according to the above braking test requirements for the braking performance of the elevator, the elevator braking performance requirements with compensation chain and the elevator braking performance requirements without compensation chain are solved respectively.

[0116] Braking performance requirements for an elevator with a compensating chain

[0117] The elevator braking deceleration is related to the brake torque of the elevator, the elevator load torque and the moment of inertia. By using the relationship between the elevator load torque and the moment of inertia of the elevator, it can be known that the angular deceleration of the elevator brake is:

[0118]

[0119] In the formula: ω is the angular deceleration of the brake, rad / s2; M b is the brake torque of the brake, N.m; M is the elevator load torque, N.m; J is the moment of inertia of the elevator, kg.m2; η is the efficiency of the elevator.

[0120] Further, the car braking deceleration α can be obtained as:

[0121]

[0122] In the formula: D y is the diameter of the elevator traction sheave, m; i is the transmission ratio of the reducer; R t is the ratio of the traction rope.

[0123] According to the 12.4.2.1 item of GB 7588-2003: "When the car is loaded with 125% rated load and runs downward at rated speed, the operating brake shall be able to stop the machine. All brake mechanical parts involved in applying braking force to the brake wheel or disc shall be installed in two groups. If one group of parts does not work, there shall still be enough braking force to slow down the car loaded with rated load running downward at rated speed." Combined with formula (2), the following can be obtained:

[0124]

[0125]

[0126] In the formula, α 100％ and α 125％ respectively represent the average deceleration of the car with rated load and 1.25 times rated load when the car is in the lowermost range of the stroke and emergency braking is performed, m / s2; M 100％ and M 125％ respectively represent the load torque when the car with rated load and 1.25 times rated load is in the lowermost range of the stroke, N.m; J 100％ and J 125％ respectively represent the total rotational inertia of the elevator brake shaft when the car with rated load and 1.25 times rated load is in the lowermost range of the stroke, kg.m2.

[0127] Formula (3) can be transformed into:

[0128]

[0129]

[0130] In the formula, P is the self weight of the car, kg; W is the weight of the counterweight device, kg; Q is the rated load, kg; g is the acceleration of gravity, m / s2; MCR is the weight of the compensating chain, kg; and MSR is the weight of the hoisting rope, kg.

[0131] The following analyzes the braking performance of the empty elevator. When the empty car runs downward at the normal operating speed to the same level position as the counterweight and emergency braking is performed (no obvious relative sliding occurs between the steel wire rope and the groove surface of the traction sheave), the following can be obtained:

[0132]

[0133] In the formula:

[0134] When the empty car runs upward at the normal operating speed to the same level position as the counterweight and emergency braking is performed (no obvious relative sliding occurs between the steel wire rope and the groove surface of the traction sheave), the following can be obtained:

[0135]

[0136] where ω emd average angular deceleration of the brake sheave when the empty car runs down to the same level position as the counterweight with normal running speed and emergency braking, rad / s 2; a emd average deceleration of the car when the empty car runs up to the same level position as the counterweight with normal running speed and emergency braking, m / s 2; ω emu average angular deceleration of the brake sheave when the empty car runs up to the same level position as the counterweight with normal running speed and emergency braking, rad / s 2; J em total moment of inertia of the brake sheave when the empty car and the counterweight are at the same level position; a emu average deceleration of the car when the empty car runs up to the same level position as the counterweight with normal running speed and emergency braking, m / s 2.

[0137] The following analyzes the difference in tension on both sides of the traction sheave caused by the traction rope, the compensating chain and the traveling cable, excluding the difference in tension on both sides of the traction sheave caused by the car self weight, the load in the car and the weight of the counterweight device. It can be obtained that:

[0138]

[0139] where T car traction rope tension on the car side caused by the traction rope, the compensating chain and the traveling cable, excluding the tension caused by the car self weight and the load in the car, N; T cw traction rope tension on the counterweight side caused by the traction rope and the compensating chain, excluding the tension caused by the weight of the counterweight device, N; H comp the number of the elevator compensating chains; g comp the weight per unit length of the elevator compensating chain, kg / m; N ct the number of the traveling cables; g ct the weight per unit length of the traveling cable, kg / m; N r the number of the elevator traction ropes; g r the weight per unit length of the elevator traction rope, kg / m.

[0140] From equation (7), it can be obtained that:

[0141]

[0142] According to TSG T7001-2009 Appendix A, when determining the balance coefficient of the elevator using the current method, the current value of the motor should be recorded when the car and the counterweight run to the same level position. Therefore, when the car and the counterweight run to the same level position, i.e. Available So, when the empty car and counterweight run to the same level, the actual weight difference on both sides of the traction sheave is That is, the balance coefficient K of the elevator is The counterweight device weight W should be:

[0143]

[0144] The above balance coefficient value is also the balance coefficient value determined by the current method, and is the most real balance coefficient value.

[0145] In order to make the elevator run more smoothly and save energy, it is required that the force difference on both sides of the traction sheave when the car is at different positions is always the same, so that the configuration of the compensating chain is:

[0146]

[0147] The following analyzes the braking performance of the elevator, and formula (9) is substituted into formula (4) to obtain:

[0148]

[0149] When the elevator is equipped with a compensating chain, formula (10) is substituted into formula (11) to obtain:

[0150]

[0151] Substituting formula (9) into formula (5) and formula (6), we obtain:

[0152]

[0153] According to formula (12) and formula (13), when the elevator is equipped with a compensating chain, the elevator brake braking performance meets the 125% rated load downline braking requirement required by GB 7588-2003 and TSG T7001-2009, and should meet:

[0154]

[0155] According to formula (12) and formula (13), when the elevator is equipped with a compensating chain, the elevator brake braking performance meets the 100% rated load single-arm downline braking requirement required by GB 7588-2003, and should meet:

[0156]

[0157] According to the requirement of elevator balance coefficient value in Appendix A of TSG T7001-2009 and the consideration of elevator operation energy saving, the value range of K is generally 0.4-0.5. In the value range, the 100% rated load single-arm down braking requirement formula (15) is more stringent. Therefore, formula (15) is the relationship between the average deceleration of the car upward braking when the empty car runs upward at the normal operation speed to the same horizontal position with the counterweight and the average deceleration of the car downward braking when the empty car runs downward at the normal operation speed to the same horizontal position with the counterweight, when the elevator brake braking performance meets the standard requirement.

[0158] Braking performance requirements for an elevator without a compensating chain

[0159] According to formula (8) and formula (9), when the elevator is not equipped with a compensation chain, the elevator brake braking performance meets the 125% rated load down braking requirement of GB 7588-2003 and TSG T7001-2009 when the elevator brake braking performance meets the 125% rated load down braking requirement of GB 7588-2003 and TSG T7001-2009, which should meet:

[0160]

[0161] According to formula (8) and formula (9), when the elevator is not equipped with a compensation chain, the elevator brake braking performance meets the 100% rated load single-arm down braking requirement of GB 7588-2003, which should meet:

[0162]

[0163] In the formula, H is the total stroke of the elevator; Q is the rated load; R t is the ratio of the traction rope; N ct is the number of elevator traveling cables; g ct is the unit length weight of the elevator traveling cable; N r is the number of elevator traction ropes; g r is the unit length weight of the elevator traction rope.

[0164] Test experiment

[0165] The detection experiment adopts the up and down running brake method of the empty load car, and establishes a dynamic model by performing emergency braking on the empty load car when running to the same horizontal position with the counterweight. The ratio of the average deceleration of the up running brake and the average deceleration of the down running brake is used as the brake performance judgment index. It is assumed that the compensation chain can completely compensate the change of the wire rope tension on both sides of the traction sheave at different car positions. The ratio of the average deceleration of the up running brake and the average deceleration of the down running brake and the relationship between the balance coefficient are used to calculate and judge whether the brake deceleration of the 125% rated load down bilateral brake and the 100% rated load down unilateral brake is greater than zero. If it is greater than zero, it is considered that the deceleration brake can be realized.

[0166] The selected elevator brand is Menarik 3000+, and the brake performance of the brake is qualified. The specific parameters are shown in the following table.

[0167]

[0168]

[0169] The detection experiment includes: control group 1: detecting the brake performance of the elevator when the 125% rated load is detected; control group 2: detecting the brake performance of the elevator when the 100% rated load is detected; experimental group: detecting the brake performance of the elevator when the empty load up and down brake is detected.

[0170] The following table is the up and down average deceleration data table of the detection experiment. The control group 1, the control group 2 and the experimental group are represented by serial numbers 1, 2 and 3 respectively.

[0171]

[0172] Unit: m / s2

[0173] According to the data in the above table, the average deceleration of the experimental group is The average deceleration of the control group 1 is The average deceleration of the control group 2 is Basically the same, and the detection results obtained by using the detection device have the advantages of high accuracy and convenient detection.

[0174] The above examples are only preferred embodiments of the present application, and do not limit the protection scope of the present application. Therefore, any equivalent changes made according to the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A device for testing elevator braking performance based on no-load testing, characterized in that, include: A sensor for detecting the speed of a traction sheave; the sensor includes a rotary transformer, which includes a stator and a rotor rotatably mounted on the stator, with an air gap between the rotor and the stator, in which a pulsating magnetic flux is generated, the axis of which is located on the axis of the windings on the stator, generating an output voltage on the windings of the rotor. The rotor windings include: cosine output windings Z1-Z2 and sine output windings Z3-Z4; the induced electromotive force on the cosine output windings Z1-Z2 is: ， Among them, E R1 E is the induced electromotive force on the cosine output windings Z1-Z2. R ΦD is the induced electromotive force on the rotor winding when the axis of the rotor winding coincides with the axis of the stator winding, and θ is the electrical angle of the rotary transformer. The induced electromotive force on the sinusoidal output windings Z3-Z4 is: ， Among them, E R2 The induced electromotive force on the sinusoidal output windings Z3-Z4 is E, and the induced electromotive force at the stator windings D1-D2 is E. D Therefore, the turns ratio on the rotary transformer is: ， Where, k u W represents the turns ratio on a rotary transformer. R W is the effective number of turns of the rotor winding. D Let be the effective number of turns of the stator winding; the following formula is derived from formulas (2-1) to (2-3): ， When the car is unloaded, the potential of the stator winding is equal to the output voltage, i.e., E. D =U f1 Formulas (2-4) and (2-5) can be written as: ， Where, k u U is the turns ratio on the rotary transformer. R1 U is the induced voltage on the cosine output windings Z1-Z2; R2 U is the induced voltage on the sinusoidal output windings Z3-Z4. f1 This is the output voltage of the rotor winding; The control device is used to calculate based on the speed of the traction sheave. and ,in, The average deceleration of the empty car when it brakes as it descends at normal operating speed until it is at the same level as the counterweight. This refers to the average deceleration of the empty car as it brakes when it travels upwards at normal operating speed until it is at the same level as the counterweight; if the elevator has a compensating chain, it will... and Substitute the following equation (15) to determine whether the inequality holds: (15)， Otherwise, a test result indicating that the elevator braking performance is unqualified will be generated; otherwise, a test result indicating that the elevator braking performance is qualified will be generated. This is the elevator's balance coefficient; A touchscreen, electrically connected to the control device, is used to visually display the test results; The control device includes a control unit, a charging circuit, a power conversion circuit, a signal conversion and conditioning circuit, a UART to USB communication circuit, and a data storage module. The sensor is electrically connected to the signal conversion and conditioning circuit. The charging circuit and the power conversion circuit are electrically connected to the lithium battery. The power conversion circuit and the UART to USB communication circuit are electrically connected to the touch screen. The signal conversion and conditioning circuit, the UART to USB communication circuit, and the data storage module are electrically connected to the control unit.

2. The elevator braking performance testing device based on no-load testing according to claim 1, characterized in that, The charging circuit includes a charging management chip, a USB interface, a lithium battery B1, an inductor L1, capacitors C1, C2, C13, C14, C15, C16, and C17, a diode D3, a light-emitting diode D1, resistors R1 and R2. The USB interface is electrically connected to the VIN pin of the charging management chip, the lithium battery is electrically connected to the BAT pin of the charging management chip, the inductor L1 is electrically connected to the LX pin of the charging management chip, and the inductor L1 is also electrically connected to the USB interface. Capacitors C1 and C2 are electrically connected to the charging diode. On the VIN and AGND pins of the charging management chip, diode D3 is electrically connected to the VBS pin of the charging management chip. Diode D3 is also electrically connected to inductor L1. Capacitors C13, C14, and C15 are electrically connected to the VBS pin of the charging management chip. LED D1 is electrically connected to the STAT pin of the charging management chip. Resistor R1 is electrically connected between LED D1 and the USB interface. Capacitors C16 and C17 are electrically connected to the BAT pin of the charging management chip. Resistor R2 is electrically connected to the ICHG pin of the charging management chip.

3. The elevator braking performance testing device based on no-load testing according to claim 1, characterized in that, The signal conversion and conditioning circuit includes a differential integrating amplifier circuit and a signal conditioning and anti-interference circuit. The sensor, differential integrating amplifier circuit, signal conditioning and anti-interference circuit and control unit are electrically connected together in sequence.

4. The elevator braking performance testing device based on no-load testing according to claim 3, characterized in that, The differential integrating amplifier circuit includes a first differential integrating amplifier circuit and a second differential integrating amplifier circuit. The first differential integrating amplifier circuit includes a differential amplifier chip U3A, input terminals CN1-1 and CN1-8, output terminal Ain, matching resistors R10, R14, R8, and R16. Input terminals CN1-1 and CN1-8 are electrically connected to the sensor. Input terminals CN1-1 and CN1-8 are located at the input terminals of the differential amplifier chip U3A, and the Ain output terminal is located at the output terminal of the differential amplifier chip U3A. Matching resistors R10, R14, R8, and R16 are located at the input terminals of the differential amplifier chip U3A. The second differential integrating amplifier circuit also includes a differential amplifier chip U3B, input terminals CN1-5 and CN1-6, and B... The output terminal, matching resistors R11, R15, R9, and R17, and the input terminals CN1-5 and CN1-6 are electrically connected to the sensor. The input terminals CN1-5 and CN1-6 are set on the input terminals of the differential amplifier chip U3B. The output terminal B is set on the output terminal of the differential amplifier chip U3B. The matching resistors R11, R15, R9, and R17 are set on the input terminals of the differential amplifier chip U3B.

5. The elevator braking performance testing device based on no-load testing according to claim 3, characterized in that, The signal conditioning and anti-interference circuit includes an A in 1 input terminal, a B in 3 input terminal, an A out output terminal, a B out output terminal, a comparator U4A, an XOR gate chip U5A, an inverter U4E, a D flip-flop U6A, a comparator U4B, an XOR gate chip U5B, an inverter U4D, and a D flip-flop U6B. The A in 1 input terminal is electrically connected to the A in output terminal, the B in 3 input terminal is electrically connected to the B in input terminal, and the A out and B out output terminals are electrically connected to the control unit. The A in 1 input terminal, comparator U4A, XOR gate chip U5A, inverter U4E, D flip-flop U6A, and B out output terminal are sequentially electrically connected together. The B in 3 input terminal, comparator U4B, XOR gate chip U5B, inverter U4D, D flip-flop U6B, and A out output terminal are sequentially electrically connected together. The CLR pin of D flip-flop U6B is electrically connected to the PRE pin of D flip-flop U6A.

6. The elevator braking performance testing device based on no-load testing according to claim 1, characterized in that, The UART to USB communication circuit includes a communication chip and two serial-to-USB interfaces mounted on the communication chip.

7. The elevator braking performance testing device based on no-load testing according to claim 1, characterized in that, The sensor includes a rotary encoder.

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