JPH07206287A - Controller for hydraulic elevator - Google Patents

Abstract

PURPOSE:To surely suppress vibration of a car cage by converting a vibration component corresponding to cage vibration into a digital value so as to input it into a vibration suppress controller and by carrying out plural phase compensation regulation corresponding to a resonance frequency of a resonance phenomenon. CONSTITUTION:A car cage 1 is lifted/lowered by supplying working fluid discharged from an oil pressure pump 9 to a hydraulic cylinder 5. A cylinder pressure sensor 6 detecting vibration generated due to a resonance phenomenon caused because of a main rope 3, an elastic modulus of working fluid, and the mass of a hydraulic plunger 4 is provided. A detection signal (a speed signal) is taken in an analogue circuit 11 consisting of a filter element, a derivative element, and an amplification element, and an acceleration signal is generated so as to be taken in a vibration suppress controller 13 via an A/D converter 12. Then, a control signal, in which feedback quantity and a phase are adjusted, is generated and is converted into a pulse duration signal in regulation circuit 14, and consequently, a pulse duration modulation rate circuit 17 is regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vibration suppression of a hydraulic elevator, and more particularly to a hydraulic elevator control device capable of suppressing vibration of a PWM control hydraulic elevator.

[0002]

2. Description of the Related Art In the prior art, as a method for suppressing vibration of a hydraulic elevator, as described in Japanese Patent Application Laid-Open No. 4-350080, the pressure of a cylinder is detected from an inverter-controlled hydraulic elevator and used as a hydraulic signal. After the hydraulic signal is differentiated by the hydraulic controller, there is a method of performing vibration suppression control of the car in addition to the limiter of the inverter device as a speed command of the electric motor via the limiter.

In Japanese Utility Model Laid-Open No. 55-136762, a vibration-proof rubber (elastic body) is attached between the pulley base and the plunger,
There is a method of controlling vibration of the car.

[0004]

In a hydraulic elevator, pulsation occurs when hydraulic oil is discharged from a hydraulic pump. This pulsation becomes a cylinder pressure through the pipe and is transmitted to the plunger to vibrate the plunger, and this vibration is transmitted to the pulley and the rope to vibrate the car. This vibration causes a resonance phenomenon in a specific frequency region due to the relationship between the rope, oil, and the plunger, and further the vibration increases depending on the car position during acceleration / deceleration.

The conventional method of attaching the vibration-proof rubber between the pulley and the plunger is insufficient to suppress the vibration.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inverter-controlled hydraulic elevator that can reliably suppress the vibration of a car and has a comfortable ride.

[0007]

In order to achieve the above object, the present invention provides a cylinder pressure sensor, an analog circuit comprising one or a plurality of elements including an element for amplifying, filtering and differentiating the output of the pressure sensor, A / D converter that converts the output of the analog circuit into a digital value, a digital circuit that takes in the digital output of the A / D converter to create a control signal, and a plurality of vibration suppression controllers that correspond to the resonance frequency in the digital circuit An adjustment circuit for converting the output signal of the vibration suppression controller into a pulse width, the output signal of the adjustment circuit is input to a modulation rate changing circuit, and the control signal of the modulation rate changing circuit is fed back to the pulse width modulation circuit. It was configured to do.

[0008]

The pressure sensor also detects the pressure corresponding to the mass of the car, the pressure related to the vibration of the car, and the pulsation generated when the hydraulic oil is discharged from the hydraulic pump. The analog circuit is
The output of the pressure sensor is amplified, noise is removed, and a signal of only the vibration component corresponding to the car vibration is extracted by the differential element. This vibration component is converted into a digital value by an A / D converter and input to the vibration suppression controller. The vibration suppression controller is equipped with multiple phase compensation adjustment circuits that correspond to the resonance frequency of the resonance phenomenon that occurs due to the relationship between the elastic modulus of the rope or oil and the mass of the plunger. The output signal of the adjusting circuit and the adjusting circuit for converting into the input signal is input to the modulation rate changing circuit, the control signal of the modulation rate changing circuit is fed back to the pulse width modulation circuit, and the vibration of the car is suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A PWM control hydraulic elevator controller according to the present invention will be described in detail below with reference to FIGS. 1, 2, 3 and 4. FIG. 1 shows a block diagram of a PWM control hydraulic elevator control device, FIG. 2 shows a block diagram of a cylinder pressure feedback control system, FIG. 3 shows a control characteristic diagram when a resonance phenomenon occurs, and FIG. FIG. 5 shows a control characteristic diagram of an embodiment according to the present invention, and FIG. 5 shows a block diagram of a control device for a PWM control hydraulic elevator.

In FIG. 1, 1 is a car, 2 is a pulley, 3 is a main rope, 4 is a hydraulic plunger, 5 is a hydraulic cylinder, 6 is a cylinder pressure sensor, 7 is a flow control valve, 8 is an oil tank, and 9 is Pump, 10 is an electric motor, 11 is an analog circuit, 12 is an A / D converter, 13 is a vibration suppression controller, 1
Reference numeral 4 is an adjusting circuit, 15 is a modulation rate changing circuit, 16 is a reference speed pattern, and 17 is a pulse width modulation rate circuit. The reference speed pattern 16 is generated from the speed command generation circuit, is taken into the pulse width modulation rate circuit 17, and the pulse width is arbitrarily changed by the pulse width modulation control to send a pulse signal to the flow control valve 7. The flow control valve 7 is roughly divided into a pilot valve and a main valve. When a pulse signal arrives, the pilot valve repeatedly turns on and off, adjusts the opening and closing of the main valve, and rotates the electric motor 10 to pump the pump. 9 sucks oil and feeds it to the hydraulic cylinder 5 through the main valve, pushes up the hydraulic plunger 4 and raises the car 1 installed on the main rope 3.

FIG. 3 shows a control characteristic diagram when the resonance phenomenon occurs. Due to the resonance phenomenon, changes in velocity and acceleration have the characteristics shown in the figure. This is due to vibrations generated by the passengers in the car due to vibration, and vibrations caused by the vibrations generated when the hydraulic oil is discharged from the hydraulic pump. At first, when a passenger vibrates in the car, the main rope 4, the hydraulic plunger 2, and the hydraulic oil resonate, causing vibration. Secondly, the discharge amount of the hydraulic pump 9 has a pulsation. At this time, pressure pulsation occurs due to pump rotation, and this pressure pulsation becomes cylinder pressure and is transmitted to the hydraulic plunger 2 and the hydraulic plunger 2 vibrates, and this vibration is transmitted to the pulley 2 and the main rope 3 and the car 1 Vibrate. Due to the relationship between the main rope 3, the elastic coefficient of oil, and the hydraulic plunger 4, this vibration causes a resonance phenomenon in a specific frequency range, and when the vibration frequency is in the same range as the resonance frequency, a large vibration occurs in the car 1. Therefore, there is a phenomenon that it affects the speed control of the elevator, makes passengers in the car uncomfortable, and significantly lowers the landing accuracy.

The present invention suppresses vibration during traveling of a PWM-controlled hydraulic elevator and provides an elevator with a comfortable ride. As shown in FIG. 1, the cylinder pressure sensor 6 detects the vibration generated by the resonance phenomenon caused by the elastic coefficient of the main rope 3, the hydraulic oil, the mass of the hydraulic plunger 4, and the like. Signal detected by cylinder pressure sensor 6 (speed signal)
Are taken into the analog circuit 11. Analog circuit 11
Is composed of a filter element, a differential element, and an amplifier element.
The (acceleration signal) output from the analog circuit 11 is captured by the control microcomputer, and thus converted into a digital signal by the A / D converter 12 and captured by the vibration suppression controller 13. In the vibration suppression controller 13, the control signal in which the feedback amount and the phase are adjusted is taken into the adjusting circuit 14 and the control signal is converted into a pulse width signal, and the modulation rate changing circuit 15 corrects the modulation rate of the pulse width to perform pulse width modulation. It returns to the rate circuit 17.

FIG. 2 shows a block diagram of a cylinder pressure feedback control system. The cylinder pressure sensor 10 detects the pulsation of the pressure discharged from the pump or the vibration of the car, and takes it into the analog circuit 11. The analog circuit 11 is the filter element 1
1a, a differentiation element 11b, and an amplifier element 11c. The filter element 11a is for removing components outside the resonance frequency region. The differential element 11b detects only the amount of change in cylinder pressure (acceleration), and the amplifier element 11c amplifies the output to a value matched with the input of the A / D converter. From the above, the output of the analog circuit is A / D
The converter 12 converts the analog signal into a digital signal and takes it into the vibration suppression controller 13. Vibration suppression controller 1
In 3, the phase compensation of the output signal of the analog circuit 11 is adjusted. With this circuit, the phase of the peak value of the car vibration at the resonance frequency is adjusted so as to be the value that can be most reduced. Two phase compensation circuits 14 are shown in the figure.
Although shown as a and 14b, the circuits can be expanded by the number of resonance points of the resonance frequency and individually controlled.

FIG. 4 shows a control characteristic diagram of an embodiment according to the present invention. The control characteristics of the present invention can suppress vibrations in both speed and acceleration, resulting in smooth control characteristics.

FIG. 5 is a block diagram of a control device for a PWM control hydraulic elevator according to another embodiment. The reference speed pattern 16 is generated from the speed command generation circuit, and the output signal is input to the differentiator 18. The acceleration signal output by adding the differentiator 18 is taken into the vibration suppression controller 13 and compared with the signal (acceleration signal) detected from the pressure sensor. As a result, the acceleration signal during normal acceleration / deceleration is ignored, and the vibration component of only disturbance can be detected. The feedback amount and phase of this signal are adjusted, the control circuit takes in the adjustment circuit 14, converts the control signal into a pulse width signal, and the modulation rate changing circuit 15 corrects the modulation rate of the pulse width and feeds it back to the modulation rate circuit 17.

[0016]

According to the present invention, since the vibration generated in the car can be suppressed by a simple method, a comfortable and comfortable hydraulic elevator that does not cause discomfort to passengers in the car can be provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device for a PWM control hydraulic elevator.

FIG. 2 is a block diagram of a cylinder pressure feedback control system.

FIG. 3 is a control characteristic diagram when a resonance phenomenon occurs.

FIG. 4 is a control characteristic diagram of an embodiment according to the present invention.

FIG. 5 is a block diagram of a control device for a PWM control hydraulic elevator.

[Explanation of symbols]

1 ... Car, 2 ... Pulley, 3 ... Main rope, 4 ... Hydraulic plunger, 5 ... Hydraulic cylinder, 6 ... Pressure sensor, 7 ... Flow control valve, 8 ... Oil tank, 9 ... Pump, 10 ... Electric motor,
11 ... Analog circuit, 12 ... A / D converter, 13 ... Vibration suppression controller, 14 ... Adjusting circuit, 15 ... Modulation rate changing circuit,
16 ... Reference speed pattern, 17 ... Pulse width modulation rate circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Kurosawa 1-6-6 Kandanishikicho, Chiyoda-ku, Tokyo Within Hitachi Building System Service Co., Ltd. (72) Keiichi Senda 1-6-6 Kandanishikicho, Chiyoda-ku, Tokyo Inside the Hitachi Building System Service (72) Inventor Hiromi Inaba 7-1-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Inside Hitachi Research Laboratory (72) Inventor Hideaki Takahashi 1070 Ichige, Katsuta City, Ibaraki Stock Hitachi, Ltd. Mito Factory (72) Inventor, Eiichi Sasaki 1070 Ige, Katsuta City, Ibaraki Prefecture Hitachi, Ltd. Mito Factory

Claims (2)

[Claims] 1. A hydraulic cylinder for raising and lowering a car via a hydraulic plunger; a hydraulic pump for supplying and discharging pressure oil from an oil tank to the hydraulic silling when the car is raised and lowered; and the hydraulic pump and the hydraulic cylinder. A flow control valve installed between and, a pilot valve for controlling the flow control valve, a pulse width modulation circuit for controlling the pilot valve,
A reference speed pattern that gives a speed command to the pulse width modulation circuit, a modulation rate change circuit that detects and calculates the car speed to correct speed control during acceleration / deceleration, an electric motor that drives the hydraulic pump, and the hydraulic cylinder In a PWM-controlled hydraulic elevator composed of a hydraulic plunger that rises by refueling oil, a pulley on the hydraulic plunger, and a car installed at a rope end on the pulley, a pressure sensor for detecting the pressure of the hydraulic cylinder, and the pressure sensor. Or a plurality of analog circuits consisting of elements for amplifying, filtering, and differentiating the output of the analog circuit, an A / D converter for converting the output of the analog circuit into a digital value, and a digital output of the A / D converter Equipped with a vibration suppression controller that responds to the resonance frequency of the signal, and output the output signal of the vibration suppression controller to the pulse width. A control circuit for a hydraulic elevator, characterized in that an adjusting circuit to be exchanged, an output signal of the adjusting circuit is inputted to a modulation rate changing circuit, and a control signal of the modulation rate changing circuit is fed back to the pulse width modulation circuit. apparatus. 2. The hydraulic system according to claim 1, wherein the vibration suppression controller includes a means for comparing an acceleration command obtained from a predetermined elevator speed pattern with an acceleration signal output from an analog circuit including a differential element. Elevator control device.