FI111930B - Hoisting motor control in lift with several landings - Google Patents

Abstract

The control of the hoisting motor (5) in a lift involves the motor drive output (25) being generated by using a speed reference and an angular speed signal and or angle signal (23) proportional to the rotation of the motor as a feedback signal and the position of the lift car (1) w.r.t. the landing. The output is measured using a sensor (10) fitted to the lift and producing a position signal (21) proportional to the height difference between the landing and the floor of the lift car. The position signal is a continuous signal utilised to generate a reference to control the hoisting motor when the car is at or close to a landing.

Description

The present invention relates to a method as defined in the preamble of claim 1 and to an apparatus for controlling a hoist motor in an elevator as defined in the preamble of claim 5.

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The departure of the lift should be soft and jerky. In order to achieve a particularly smooth and jerk-free start of the elevator car, the elevator hoisting motor is conventionally controlled using a purpose-tuned speed reference 15 and a feedback cruise control. Typically, a speed-measuring tachometer from the motor shaft that provides a voltage or pulse rate proportional to the speed is used as the feedback element. However, the elevator car does not always move as you would imagine following the speed of the motor shaft. Elevator guides, especially for sliding guides, may be so tight that a considerable "extra" engine torque is required before the elevator starts to overcome resting frictions before the motor shaft begins to rotate. The same is true of lifting machinery with bearings for bearing rest- «· · \" Z5 cat. The internal frictions of bearings and lifting gear are particularly relevant in gear lifts. · * This easily results in a situation where the speed reference and often also the difference in speed has increased \. \: kat has been overcome. When the elevator car finally starts to emit:, S0, speed detection from the motor shaft makes it impossible to prevent a jerk in the elevator car, especially: if the elevator ropes are stretched, the energy is released and then discharged • *, consider lower motion friction, which may be due to the lack of correct, $ 5 * accurate and timely feedback information * * * ··· 'in the elevator car position and / or commercial space.

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The 2 111930 torque needed to overcome the frictional friction at start of lift should be able to reduce the body movement space and system movement frictions to the torque in a timely manner, but since there is no direct information on the body speed level, Differences in motion, the moment corresponding to resting friction will easily remain 'on' for too long. This easily results in an output spin when the car starts to move, which then continues in damping vibration.

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As a solution to the starting motion and oscillation problem, an accelerometer located in the body is proposed, the acceleration signal of which would be converted into a body speed message, which would further adjust the body speed rather than the motor shaft speed. However, the acceleration-15 sensor is expensive and sensitive as a component and the signal it provides requires a high-quality amplifier to provide a reliable signal.

In order to meet the above-mentioned needs and to solve problems, the present invention provides an apparatus and method for controlling a lift motor in an elevator. For the method according to the invention. is characterized in what is set forth in the characterizing part of claim 1. The apparatus according to the invention is characterized by what is stated in the characterizing part of claim 5 .25. Other embodiments of the invention are characterized by what is stated in the other claims.

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Advantages can be achieved with the invention e.g. as follows: The solution of the invention is simple to implement with current microprocessor based control systems.

• · · * - When starting the lift, the initial jerk will be removed, or at least • * 4 will decrease significantly. Since the position and velocity of the car provide feedback to the cruise control throughout the departure event, • ♦ · also detects, for example, the friction of the car's sliding controls .35 · the 'moment of victory', ie the slightest movement of the car. In this case, the engine torque can be adjusted in time to match the body speed.

111930 3 The list can be removed by actively adjusting the engine based on actual information about the oscillation state.

-Excellent and fast output layout can be achieved without the need for expensive additional electronics.

5 -When leaving the floor level, the elevator will quickly receive the correct feedback signal.

The invention is applicable to elevator modernizations, whereby the performance characteristics of the lifting and launching of the elevator can be improved in a simple manner.

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The invention will now be described in more detail with reference to the accompanying drawings, in which Fig. 1 schematically illustrates an elevator applying the invention, Fig. 2 illustrates a signal from a linear transducer, Fig. 3 shows a block diagram of an embodiment of the invention, and Fig.

• * * * ··· The linear sensor is a component that provides a current proportional to the distance between the sensor and the reference point · · *.

9 .25 message. In the invention, this message is utilized to control the deceleration and start of the elevator * · «. linear transducers

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| as an aid, the position and velocity of the elevator car are measured with the elevator within a certain distance window from the floor level and the result is used as a feedback signal in the elevator hoist motor control. While preparing for the departure of the lift and the brake arches, ··, ·. opening position, the positioning data available from the linear sensor »» · can be used to control the hoisting motor to hold the elevator car in place "·" · until the brake is released and the elevator moves

Ml properly. Preferably, a suitable linear transducer is a VAC .35: VACUUMSCHMELZE T60500-X5810-X010-51 sensor that provides a linear signal proportional to the relative position of the sensor and the position reference magnet over a distance of 150mm.

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Figure 1 schematically shows an elevator. The hoisting rope 3 has an elevator car 1 and a counterweight 2 hung on the hoisting rope. The drive wheel is rotated by a lifting 5 motor 5. The movement of the drive wheel is obtained by a tachometer 6 located on the axis rotated by the lifting motor 7. The elevator serves a plurality of floor levels 8. In the floor planes, preferably each floor level, which gives a signal depending on the position of the sensor and the magnet. The sensor and magnet are disposed relative to the elevator car and the floor plane so that the signal is linear when the threshold of the elevator car and the plane are within a certain distance window 15 relative to one another. The drive wheel 4 has a brake surface 11 for the elevator brake shoe 12.

Figure 2 illustrates a typical signal 13 provided by a linear sensor type sensor placed in an elevator car while the elevator 20 is traveling at a constant speed past the floor level. The resulting signal is plotted against time. So I saw someone moving in the elevator shaft. the position of the elevator car relative to the floor level is measured using a sensor in the elevator car which provides a position signal proportional to the height difference between the floor level and the floor of the elevator car.

• · · 25 Using the position signal, you can create a

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The engine is controlled at and near the floor level.

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Figure 3 illustrates an embodiment of the invention in a simple block diagram. In the embodiment, the most suitable switching signal »» · · for the movement and position of the elevator is selected. The selection of feedback is done by the feedback | »» * '* In selection and scaling unit 126, which selects feedback signal 123 as either tachometer signal 127 or • 36 · linear sensor signal 121. Depending on the selected feedback signal · ·, ·. the signal to be covered determines whether the motor is controlled primarily by position or speed control, while selecting whether to run based on position 128 or speed reference 124 5 111930. A preferred way is to change the position feedback to a speed feedback when the set distance from the output level has been reached or the set time from the output has elapsed. The decision can also be made on other grounds. Upon reaching the destination layer 5, switching from speed feedback to position feedback can be made, for example, when it has been determined from the tachometer signal that the elevator car is at a distance from the plane such that the signal from the linear sensor is linear. The selection and scaling unit 126 10 also performs the necessary signal matching to the motor control switch field. The tachometer 6 provides a signal proportional to the lift motor speed 127 which is used as a feedback signal for most of the distance traveled by the elevator car 1 from the departure layer to the destination layer.

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At the elevator start position, the distance information 121 relating to the elevator car 1 provided by the linear sensor 10 is read for use in motor control feedback. Initially, the output 125 of the motor control pi controller servo unit 122 is adjusted 20 by the position feedback 121 based on the selected feedback signal 123 and the position reference 128. Departure is as follows. The positioner compares the positioning information based on the • • * non-linear sensor signal with the position reference * 'and, based on the difference between position reference and position information, gives a torque-> ·> • 25 reference to the motor. Initially, 0 - i t position guidance is given until the brake is released. The feedback f f is taken from the linear sensor. Thereafter, the position instruction is started to be changed so that the movement of the elevator car takes place at the set acceleration and change of acceleration. The movement of the motor shaft • 5¾ may differ from the corresponding movement of the elevator car, but as you move, the smooth, jerky movement of the elevator car is significant. After departure, at a predetermined .ntt position, or when the linear transducer range I '<! *, 'ends, changing position control to speed control.

»Work; The feedback signal is then taken from the tachometer. In the shift, the integral term of the position control transfers the velocity control to the integral term and the initial value of the velocity reference is set to the current speed measured by the tachometer from the motor axis.

6111930

The block diagram of Fig. 4 shows another embodiment of the invention. The motor control output 225 is formed in the drive unit 222. The drive unit is controlled by the speed and 5-position instructions 202 and 201. The drive unit 222 is controlled by either the instruction 202 or the instruction 201 or the interaction of the instructions 201 and 202 depending on the elevator car. The rate-based instruction 202 is generated in the rate controller 212 and the location-based instruction 201 is generated in the position controller 211. The rate signal 227 from the tachometer 6 is feedback to the rate controller 212 and the position signal 221 from the linear sensor 10 is feedbacked to the position controller 210 224 controls the rate control 212. 15 Integration unit 228 integrates from the rate reference to form a position reference 223 which controls the position controller 211. The rate signal 227 controls the generation of the relative positioning and rate control weighting factors k1 and k2. The positioning and velocity weighting are done as follows. The position control weighting factor k1 is 1 and the speed control weighting factor k2 is 0 when the elevator car is stopped at floor level 8. The weighting coefficients change from 1 to 0 and from 0 to 1 as the elevator speed changes from zero to the set limit speed. The boundary speed set at the start • • · * • 25 is always reached before the elevator car has traveled further than the linear range of the linear sensor. Weighting 226 is controlled by the speed signal 227 from the tachometer. Position: j: the sum of the weighting factor k1 and the speed adjustment weighting factor k2 is 1. Preferably, k1 decreases and k2 increases non-jumping with speed 30 from zero to the set limit. Set-:. ·. At speeds above this limit, kl = 0 and k2 = 1.

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When the elevator car 1 is located between the planes outside the linearly dependent region of the linear sensor * 'signal 13, the movement of the elevator car is controlled only by speed control, even if the speed is low.

It will be apparent to one skilled in the art that the various embodiments of the invention are not limited to the examples above, but may vary within the scope of the following claims. For example, at the floor level, the distance measuring arrangement may be based on more than the detection of a magnetic 5 field, such as an optical position sensor. Similarly, it will be apparent to one skilled in the art that the motor drive may be otherwise configured. It is also clear that while the examples presented above primarily illustrate matters from the point of view of starting the elevator, the control according to the invention is also suitable for use in level-stopping.

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Claims (8)

8111930 A method for controlling a hoist motor (5) in an elevator having a plurality of floor planes (8) and using the speed reference (124,224) and generating the motor drive output 5 (125,225) as a feedback signal and an angular speed and / or angular signal 1) the position relative to the floor level (8) is measured using a sensor (10) in the elevator car adapted to provide a position signal (121,221) proportional to the height difference between the floor and the elevator car, characterized in that the elevator car exits or stops 125, 225) is formed using position reference (128,223), and that the control of the 15 lift motors is feedback by a speed signal (127,227) using the speed reference (124,224) and a position signal (121,221) using the position reference (128,223). Method according to Claim 1, characterized in that it is controlled by the position reference (128,223) or the velocity reference (124,224) by the distance from the floor level (8) of the elevator car (1). . 3. A method according to claim 1, characterized in that it is controlled based on the speed of the elevator car (1), whether controlled by the position reference (128,223) or the speed reference '·' (124,224). • * 9 The method according to any one of the preceding claims:! : 30 characterized in that the control of the hoisting motor is changed from a control based on a position reference (128,223) to a speed reference. (124,224) through both position and velocity based control. • · · i · • tl '* .35 Apparatus for controlling the lifting motor (5) in an elevator having a plurality of floor levels (8) and having an output of motor drive. . ·. (125,225) is formed using the speed reference (124,224) and. angular speed and / or angle signal (127,227) proportional to rotation of the hoisting motor as a feedback signal and the elevator shaft has at least one position reference (9) fixedly fixed relative to the floor level (8) and the position reference (10) adapted to provide a position signal (121, 221) proportional to the height difference between the floor level and the elevator car floor, characterized in that the apparatus has a position reference (128, 223) and that the motor output (125, 225) is controllable by the position reference (128, 223); the feedback is made with the velocity signal (127,227) using the velocity reference (124,224) and the position signal (121,221) using the position reference (128,223). Apparatus according to claim 5, characterized in that the location reference (9) is on each layer level (8). Apparatus according to Claim 5 or 6, characterized in that the apparatus comprises a unit (126) adapted to select either a speed signal (127,227) or a position signal (121,221) as a feedback signal and either a speed reference (124,224) or a position reference (128,223). . Apparatus according to claim 5 or 6, characterized in that the apparatus comprises a motor control (222) - a 25 position feedback positioner (211) and a speed feedback device (212) and a unit (226) adapted to weight the positioner (211) and the relative effect of the speed control (212). ; T: 30 »Il t I» »I * · 10 111930