US3918552A - Elevator control system - Google Patents

Elevator control system Download PDF

Info

Publication number
US3918552A
US3918552A US435972A US43597274A US3918552A US 3918552 A US3918552 A US 3918552A US 435972 A US435972 A US 435972A US 43597274 A US43597274 A US 43597274A US 3918552 A US3918552 A US 3918552A
Authority
US
United States
Prior art keywords
motor
output
elevator car
dead zone
braking
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US435972A
Other languages
English (en)
Inventor
Tadao Kameyama
Akinori Watanabe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Application granted granted Critical
Publication of US3918552A publication Critical patent/US3918552A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B1/00—Control systems of elevators in general
    • B66B1/34—Details, e.g. call counting devices, data transmission from car to control system, devices giving information to the control system
    • B66B1/36—Means for stopping the cars, cages, or skips at predetermined levels
    • B66B1/40—Means for stopping the cars, cages, or skips at predetermined levels and for correct levelling at landings

Definitions

  • FIG. I0 (I KY0 Q1 N V ak 2 T if 1 555522 I J 1 B )6 Yl if PHASE v V SHIFTER iz i-;, -6 DEAD ZONE CIRCUIT SPEED PATTERN "4 8 Y GENERATOR I AND RELAY gE cEL RATloAl AR me POSITION RELAY .DETECTOR US. Patent Nov. 11,1975 Sheet 8 of8 3,918,552
  • This invention relates to a system for controlling an elevator car driven by an A.C. motor. and more particularly to improvements in a deceleration control system for an elevator car in which negative feedback control is employed for controlling the braking force for stopping the elevator car at a desired target floor.
  • An elevator car driven an A.C. motor is generally controlled in "such a manner that the A.C. motor does not generate anydriving force during application of the brake and the braking force issolely utilized to stop the elevator carat a desired target floor position, since this manner of control is advantageous for the simplification and reduction in the costsof the elevator system.
  • the load of an elevator car varies greatly depending on time. More precisely, the motor driving the elevator car operates in a heavy loaded state during a certain period of time as when theelevator car carrying no passengers moves downward or when the elevator car full loaded with passengers moves upward. During another period of time, the motor driving the elevator car operates in a no-loaded state as. when the elevator car carrying no passengers moves.upward or when theelevator car full loaded with passengers moves downward.
  • the moving speed of the elevator car is slow in the former case and the load of the motor assists in applying the braking force to the elevator ear compared with. the latter case.
  • Another object of the present invention is to provide an elevator control system which ensur es satisfactory performance in spite of the fact that the capacity ofeleva tor car driving means is relatively small. 7
  • the load of a motor driving an elevator car is detected. and the distance between the position at which application of the brakeis started (the position of cutting off the motor from the power supply) and the stopping position of the elevator car is varied depending on the load.
  • the elevator caris required to stop exactly at the desired :target floor position. Therefore. in order to exactly stop the elevator car at the desired target floor -posit ion, the load of the motor driving the elevator car is detected tochange the brake application starting position on the basis of the detected load.
  • a first signal is generated from means which provides a deceleration pattern so as to stop the elevator car sufficiently smoothly at the desired target floor position even when the motor is in a no-loaded state. and application of the brake is started in suitably delayed relation from the point of appearance of the first signal depending on the load so as to ensure a desirable braking characteristic free from load variations.
  • FIG. 1 is a block diagram of an embodiment of the elevator control system according to thepresent invention. 7
  • FIG. 2 shows the waveform of a voltage signal generated from the speed pattern instruction signal generator 4 shown in. FIG. 1;
  • FIG. 3 is a graphic representation of the relation between the torque and the speed when deceleration of the elevator car is started under a heavy load
  • FIG. 4a is a graphic representation of variations of deceleration in response to the application ofthc brake in the embodiment of the present invention shown in FIG. I; r
  • FIG. 4b is a graphic representation of variations of deceleration in response to the application of the brake in a priorart system.
  • FIG. .5 shows-the control characteristic of the first embodiment of the present invention compared with that of the prior art system;.
  • FIG. 6 is a block diagram of another embodiment of the present invention.v
  • FIG. 7 is a circuit diagram showing a practical structure of the comparator in thesystem shown in FIG. 6;
  • FIG. 8 shows the period of time between the deceleration starting time I, and the brake application starting time r relative to the motor load in the embodiments shown in FIGS. 1 and 6;.
  • FIG. 9 is a block diagram of still another embodiment of the present invention.
  • FIGS. 11a and 111 show other voltage signal waveforms preferably employed in the present invention.
  • an induction motor 7 for driving an elevator car is, connected to a three-phase A.C. power supply 1 through relay contacts Y of a relay Y.
  • a resistor 9 is shorted by a relay contact X of a relay X.
  • the input terminals V and W of the induction motor 7 are further connected to the three-phase A.C. power supply 1 throughrelay contacts Y,, of the relay Y and a braking rectifier 2 which is composed of a pair of thyristors SCR and a pair of diodes SR.
  • the angular velocity of the rotating induction motor 7 is detected by a speed detector 5 which is mechanically coupled to the induction motor 7.
  • the output V, ofthe speed detector 5 is compared with the output V ofa speed pattern instruction signal generator 4, and the error signal V,- obtained by comparing these signals V and V, with each otheris applied to a phase shifter 12 which controls the thyristors SCR in the rectifier 2.
  • the negative feedback control is such that the direct current supplied to the induction motor 7 is increased to increase the braking force when the rotating speed of the motor 7 is high, while this current is decreased to decrease the braking force when the rotating speed of the motor 7 is low.
  • the error signal V is also applied to a circuit 6 having r 3 a dead zone characteristiuand this dead zone circuit 6 operates when the error signal V,- is greater than the opcrating voltage level V thereof. During deceleration of the elevator car.
  • the speed pattern instruction signal generator 4 generates a voltage signal instructing the deceleration pattern for the elevator car in response to the application of a signal from a deceleration starting position detector 3.
  • the relay X is deenergized by the signal applied from the deceleration starting position detector 3. and the contact X ofthe relay X is opened.
  • AnAND gate Sis actuated when both the output ofthe dead zone circuit 6 and the output ofthe detector 3'are applied therct0.'ancl the relay Y is deenergized by the output of the AND gate 8.
  • the elevator car deceleration pattern signal generated from the speed pattern in struction signal generator 4 has a voltage waveform as shown in'FlG. 2.
  • the relay Y is in the energized state and the contacts Y,, thereof are in the closed position. ln this case. the relay X is also in the energized state and the contact X thereof is closed to short the resistor 9.
  • the induction motor 7 is rotating in one direction and the elevator car is moving toward the desired target floor.
  • the motor 7 operates under a heavy load or no load depending on the moving direction of the elevator car and the load carried by the elevator car. In the state in which the motor load is heavy. the rotating speed of the motor7 is low and the output of the'speed detector is also low. Conversely. in the state in which the motor load is nearly equal to no load. the rotating speed of the motor 7 is high and the output ofthe speed detector 5 is also high.
  • the elevator car moves at a constant low speed and the output V of the speed detector 5 is lower than the output V,- ofthe speed pattern instruction signal generator 4 at time l
  • the elevator car may stop at a position above or below the'target floor position due to the braking effect ofthc motor load when the motor 7 is cut off from the power supply 1 at this time 1,. In the present embodiment.
  • the heavy loaded motor 7 is cut off from'the power supply 1 when the output V,, of the speed detector 5 is increased up to a level which is higher by a predetermined value or setting V than the output V of the speed pattern instruction signal generator 4.
  • the outputs V,, and V. of the speed detector 5 and speed pattern instruction signal generator 4 respectively are applied to a comparing point at which V, is compared with V, to give an error signal V,. and this error signal V isapplied to the dead zone circuit 6 which is set to operate when the input thereto exceeds the operating voltage level V, thereof.
  • the error signal V,- is greater than the operating voltage setting V, and an output appears from the dead zone circuit 6 to be applied to the AND gate 8. Since the output signal of the deceleration starting position detector 3 has already been applied to the AND gate 8, an output appears from the AND gate 8 to be applied to the relay Y.
  • the relay Y is deenergized with the result that the contacts Y disposed in the current path between the motor 7 and the power supply I are opened, and the contacts Y disposed in the current path between the rectifier 2 and the motor 7 are closed.
  • the error signal V,- obtained by comparing the output V of the speed detector 5 with the output V. of the speed pattern instruction signal generator 4 is also applied to the phase shifter 12 which acts to control the firing angle of the thyristors SCR in the rectifier 2 depending on the level of the error signal V,- thereby controlling the value of direct current used for braking.
  • the rotating speed of the motor 7 mechanically coupled to the elevator car can be reduced to conform to the speed pattern signal generated from the speed pattern instruction signal generator 4.
  • the relay X is also deenergized by the output of the deceleration starting position detector 3 and the contact X,, thereof is opened'Howe ver, this relay X does not substantially participate in the operation of the system in the noloaded state of the motor 7 due to the fact that the relays X and Y are substantially simultaneously deenergized.
  • the relay Y appears from the dead zone circuit 6 and an output appears from the AND gate 8 to deenergize the relay Y.
  • the contacts Y,, of the relay Y are opened and the contacts Y,, are closed to start application of the brake.
  • the relay X is deenergized at time r in response to the application ol'the output from the deceleration starting position detector 3 and the contact X thereofis opened. Due to theopening ofthe contact X the resistor 9 interposed between the power supply 1 and the motor 7 becomes active toreduce the motor torque to, for example, such a torque value which is substantially intermediate between the torque value developed by the motor 7 when the full voltage is applied thereto and the torque value devel-' oped by the motor 7 when no voltage is applied thereto.
  • Such intermediate torque appears between time t and time t in FIG. 2.
  • no voltage is applied to the motor 7 during the period of time corresponding to the difference between the operating time of the quick responsive contacts Y,, and slow responsive contacts Y,, of the relay Y, and then the braking action takes place.
  • FIG. 3 shows the relation between the torque and the speed when the deceleration is started 'in the state in which the motor 7 is heavy loaded.
  • the curve D represents the torque-speed characteristic when the full voltage is supplied to the induction motor '7
  • the curve E the torque-speed characteristic when the resistor 9 is activated
  • the curve F the torque-speed characteristic when the brake is applied to the induction motor 7.
  • the rotating speed increases with the decrease of the slip S toward zero and decreases with the increase of the slip S toward unity.
  • a point p on the torque-speed characteristic curve D represents the operating point of the motor 7 when the motor 7 is operating in the steady state.
  • the operating point of the motor '7 shifts from the point p on the curve D to a'point q on the curve E due to the fact that the resistor 9 interposed between the motor 7 and the power supply 1 becomes active. Thereafter, the torque increases along the curve E with the reduction of the rotating speed of the motor 7 and the operating point shifts from q to r at time 1 At.
  • the relay Y is deenergized to cut off the motor 7 from the power'supply l.
  • the operating point shifts from r to u. and with the further reduction of the rotating speed.
  • theoperating point shifts from u to w on the curve F when the application of the brake is started.
  • the rotating speed of the motor 7 is controlled by the feedback of the speed.
  • the vibration due to the variation of the torque at time I, and the vibration due to the variation of the torque attime 1 can'- cel each other so that a substantially vibration-free braking effect can be obtained.
  • the period of time of from I to 1 is preferably selected to be equal to one-fourth of the period of the natural vibration of the elevator system.
  • the natural frequency of the elevator car is variable depending on the length of the rope by which the elevator car is suspended.
  • the natural frequency of commonly presently employed elevator cars is of the order of Sto 2 Hz. Therefore, good results can be obtained when the period of time of from t, to r is selected to lie within the range of from 50 ms to 150 ms. This period of time of from t to L is determined by the setting V ofthe.
  • the resistor 9 is activated at time I, and the rotating speed of the motor 7 is reduced during the period of from time I to time 1 at which the application of the brake is started.
  • the 'shockcan be alleviated in the initial stage of application of the brake.
  • FIG. 4a shows the rate of variation of deceleration during application of the brake in the system of the present invention shown in FIG. 1. while FIG. 4b shows that in the'priorartsystem. It will be seen that the variation in FIG. 4a is less than that in FIG. 4b. and therefore. passengersin the elevator car feel a better sense of ride.
  • FIG. 5 shows the distance which the decelerated elevator car runs with inertia in the state in which the motor 7 is heavy loaded.
  • the dotted line A or bu represents the manner of deceleration of the elevator car in the case in which the resistor 9 is activated between time 1 and time t to provide a shock alleviating period as-above described.
  • the solid line B or an represents the manner of. .deceleration of the elevator car in the case in which the motor 7 is cut off from the power supply l as soon as the deceleration starting position de tector 3 is placed in operation. During the period of time of from t, toutthe rotating speed of the motor 7 is reduced slowly due to the shock alleviating effect of the resistor 9.
  • the distance which the decelerated elevator car starts to run with inertia simultaneously with theoperation of the deceleration starting position detector 3 is represented by the area of the triangle at;; 1 It will therefore be seen that the distance which the decelerated elevator car runs with inertia in-the former case is longer than that in the latter case bythe area of the tetragon (1 )[413- Thus. the deceleration control of the elevator car can be achieved with an allowance which corresponds tothe difference above described.
  • FIG. 6 shows another embodiment of the present invention and like r'eference numerals are used therein to denote like parts appearing in FIG. 1.
  • a comparator 101 includes a pair of inverters l0 and ll.
  • The'outputs V and V of a speed detector 5 and a speed pattern instruction signal generator 4 respectively are compared with each other after being inverted by'the inverters l0 and 11 so that the polarity of the input V to a phase shifter 12 is opposite to that of the input V to a dead zone circuit 6 having a dead zone characteristic.
  • the technical effect of this embodiment is substantially the same as that of the embodiment shown in FIG. 1. However.
  • this second embodiment is advantageous in that the input V to the dead zone circuit 6 can be derived without being interfered by the input V to the phase shifter 12 due to the fact that the output V,, of the speed detector 5 is compared with the output V,. of the speed pattern instruction signal generator 4 by comparing means which are arranged as shown.
  • FIG. 7 shows one practical form of the comparator 101 shown in FIG. 6. Referring to FIG. 7, resistors (R R R R and R constitute a bridge circuit to which the output V of the speed detector 5 and the output V of the speed pattern instruction sig- 7 nal generator 4 are applied. A pair of terminals I02 and 103 are connected to the phase shifter 12. and another pair of terminals I and 106 are connected tothe dead zone circuit 6.
  • the period of time T between time t, (at which deceleration of the elevator car is started) and time (at which application of the brake is started) may be set to vary depending on the load as shown by the solid linea in FIG.
  • this period of time T may be shortest inthe vicinity of an intermediate load and may be successively increased toward a heavier load as shown in FIG. 8. Further. this period of time T may be delayed by T relative to the line a in a heavy load range as shown by the dotted line b in FIG. 8. That is. a better effect can be obtained in a heavy load range by delaying the speed pattern output of the speed pattern instruction signal generator 4 by T.
  • the load of the motor 7 is heavy when the result of comparison between the output,V
  • the output of the deceleration starting position detector 3 may heapplied through a suitable delay means to the speed pattern instruction signal generator 4, so that the brake can be applied according to a braking characteristic as shown by the dotted line b in FIG. 8.
  • the deceleration starting position detector 3 operates at time and the output voltage of the speed pattern instruction signal generator 4 starts to decrease at time 1 which is delayed from time t by r corresponding to T shown in FIG. 8.
  • the period of time between time 1 and time t at which application of the brake is started is longer by I than the corresponding period of time shown in FIG. 2.
  • the notch change-over time during deceleration. that is. the period of time of from I, to 1;, can be easily set at the optimum value.
  • difficulty may be encountered in obtaining proper timing for deceleration due to the fact that determination of the deceleration pattern or determination of the inclination is restricted from.
  • FIG. 9 shows another embodiment of the present invention. Actually. this embodiment is a modification of the embodiment shown in FIG. I and means is provided so as to vary the output voltage of the speed detector 5 for obtaining a delay time I as shown in FIG. llb. Such a delay time I may also be obtained by varying the output voltage of the speed pattern instruction signal generator 4. Referring to FIG. 9, a resistor 14 is inserted in the output circuit of the speed detector 5 to reduce the output voltage ofthe speed detector 5 for obtaining the delay time t.
  • FIG. shows another embodiment of the present invention and is actually another modification of the embodimentshown in FIG. I for obtaining thesame effeet as that described with reference to FIG. 9.
  • a current transformer 15 and a converter' 16 are additionally provided so that the current input to the motor 7 can be compared with the output ofthe speed pattern instruction signal generator t.
  • the current input-to the motor 7 under 'a heavy load is large 8 compared with that under a light load. and this current input is larger during accelerationthan that during steady state operation.
  • the current in the line connected to the terminal W is large compared with that in the line connected to the terminal V due to the presence of the resistor 9 in the latter line.
  • a system for controlling the braking force applied to an elevator car comprising a motor for driving the elevator car, means for detecting the speed of the elevator car. means for detecting the deceleration starting position for the elevator car. circuit breaking means for cutting off said driving motor from the power supply, means for generating a braking pattern signal for applying the braking force to the elevator car in response to the application of. the output of said deceleration starting position detecting means. and means for comparing the output of said braking pattern signal generating plying the braking force to the elevator car can be.
  • said means for delaying the initiation of the operation of said circuit breaking means and said means applying the braking force to the elevator car comprises means for detecting the load of said motor.
  • said means including said motor load detecting means for delaying the initiation of the operation of said circuit breaking means and said means applying the braking force to the elevator car comprises a dead zone circuit from which an output appears to actuate said circuit breaking means. when the difference between the output of said elevator car speed detecting means and the output of said braking pattern signal generating means exceeds a predetermined setting of said dead zone circuit.
  • said motor torque reducing means beingadapted to op- 9 crate in response to the appearance of the output from said deceleration starting position detecting means.
  • a relay is actuated by the output of said dead zone circuit, and said braking force applying means comprises rectifier means for supplying D.C. braking current to said motor and a phase shifter for controlling said rectifier means, said relay having first contacts disposed between said motor and the power supply and second contacts disposed between said rectifier means and said motor so that said first and second contacts can be opened and closed respectively in response to the appearance of the output from said dead zone circuit.
  • said relay having first contacts disposed between said motor and the power supply and second contacts disposed between said rectifier means and said motor so that said first and second contacts can be opened and closed respectively in response to the appearance of the output from said dead zone circuit.
  • a system for controlling the braking force applied to an elevator car comprising a motor for driving an elevator car;
  • third means responsive to said second output signal, for issuing a braking pattern signal representing a predetermined deceleration pattern for the elevator car;
  • said fifth means for delaying by predetermined times depending on the load of said motor the initiation of the operations of said circuit breaking means and said fourth means with respect to the issuance of said second output signal, said fifth means including dead zone circuit means for generating an output permitting said circuit breaking means to be actuated during a period of time when the value of the difference between said first output signal and said braking pattern signal exceeds a predetermined setting of said dead zone circuit means.
  • said circuit breaking means comprises first relay means disposed between said motor and the power supply. said first relay means having contacts which are opened in response to the concurrence of said second signal and said output of said dead zone circuit means; and said fourth means includes rectifier means for supplying D.C. braking current to said motor. phase shifter means for controlling said rectifier means. and second relay means disposed between said rectifier means and said motor. said second relay means having contacts which are closed in response to the concurrence of said second signal and said output of said dead zone circuit means.
  • a system for controlling the braking force applied to an elevator car comprising;
  • third means responsive to said second output signal for issuing a braking pattern signal representing a predetermined deceleration pattern for the elevator car;
  • said fifth means for delaying by predetermined times depending on the load of said motor the initiation of the operations of said circuit breaking means and said fourth means with respect to the issuance of said second output signal, said fifth means including sixth means for detecting current of said motor to indicate the load thereof. said sixth means having an output representative thereof, and
  • dead zone circuit means for generating an output permitting said circuit breaking means to be actuated during a period of time when the value of the difference between the output of said sixth means and said braking pattern signal exceeds a predetermined setting of said dead zone circuit means.
  • said circuit breaking means comprises first relay means disposed between said motor and the power supply, said first relay means having contacts which are opened in response to the concurrence of said second signal and said output of said dead zone circuit means; and said fourth means includes rectifier means for supplying D.C. braking current to said motor, phase shifter means for controlling said rectifier means. and second relay means disposed between said rectifier means and said motor, said second relay means having contacts which are closed in response to the concurrence of said second signal and said output of said dead zone circuit means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Elevator Control (AREA)
  • Stopping Of Electric Motors (AREA)
  • Control Of Direct Current Motors (AREA)
US435972A 1973-01-24 1974-01-23 Elevator control system Expired - Lifetime US3918552A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP954173A JPS5417219B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1973-01-24 1973-01-24

Publications (1)

Publication Number Publication Date
US3918552A true US3918552A (en) 1975-11-11

Family

ID=11723116

Family Applications (1)

Application Number Title Priority Date Filing Date
US435972A Expired - Lifetime US3918552A (en) 1973-01-24 1974-01-23 Elevator control system

Country Status (8)

Country Link
US (1) US3918552A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
JP (1) JPS5417219B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
AU (1) AU466364B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
BR (1) BR7400484D0 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
CA (1) CA1019480A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
DE (1) DE2403204C3 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1456434A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
HK (1) HK40177A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4083431A (en) * 1975-05-09 1978-04-11 Hitachi, Ltd. Elevator control apparatus
US4181197A (en) * 1977-04-15 1980-01-01 Mitsubishi Denki Kabushiki Kaisha AC elevator speed control system
US4319665A (en) * 1979-05-11 1982-03-16 Hitachi, Ltd. AC Elevator control system
US4499972A (en) * 1981-03-04 1985-02-19 Elevator Gmbh Speed control system for a motor with short-circuited rotor
US4700811A (en) * 1985-03-25 1987-10-20 Sarl Logilift Method for the regulated control of a moving body carrying a variable load
US6029951A (en) * 1998-07-24 2000-02-29 Varco International, Inc. Control system for drawworks operations
US6318505B1 (en) * 1999-06-25 2001-11-20 Inventio Ag Device and method for preventing vertical displacements and vertical vibrations of the load carrying means of vertical conveyors
US20040085034A1 (en) * 2002-11-01 2004-05-06 Kuras Brian D. System and method for controlling a motor
EP1464611A3 (de) * 2003-03-31 2004-12-08 Demag Cranes & Components GmbH Verfahren zur Laufberuhigung einer Gliederkette eines Kettenzuges, insbesondere zur Verhinderung der Ausbildung einer Resonanzschwingung der Gliederkette, und einen Kettenzug hierfür
CN101844715A (zh) * 2010-06-11 2010-09-29 日立电梯（中国）有限公司 新型电梯制动器控制系统
US20100318360A1 (en) * 2009-06-10 2010-12-16 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for extracting messages
US20110012718A1 (en) * 2009-07-16 2011-01-20 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for detecting gaps between objects
US20110091311A1 (en) * 2009-10-19 2011-04-21 Toyota Motor Engineering & Manufacturing North America High efficiency turbine system
US20110153617A1 (en) * 2009-12-18 2011-06-23 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for describing and organizing image data
US8424621B2 (en) 2010-07-23 2013-04-23 Toyota Motor Engineering & Manufacturing North America, Inc. Omni traction wheel system and methods of operating the same
CN102482049B (zh) * 2009-09-09 2014-01-29 三菱电机株式会社 电梯控制装置
WO2017001884A1 (en) * 2015-07-01 2017-01-05 Otis Elevator Company Monitored braking blocks
US20170057782A1 (en) * 2014-02-19 2017-03-02 Otis Elevator Company Improved elevator releveling control

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5411050B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1973-05-26 1979-05-11
GB1524298A (en) * 1975-04-03 1978-09-13 Otis Elevator Japan Control apparatus for an elevator system
SE445444B (sv) * 1979-12-28 1986-06-23 Elevator Gmbh Styrsystem for elektrodynamisk och mekanisk bromsning av drivaggregat till person- och varupersonhissar
DE3030793A1 (de) * 1980-08-14 1982-03-11 Otis Elevator Co., Hartford, Conn. Aufzuganlage und verfahren zur betriebssteuerung derselben
JPS58110778A (ja) * 1981-12-23 1983-07-01 ワイケイケイ株式会社 自動開閉扉の制御装置
DE3422351A1 (de) * 1983-06-16 1984-12-20 Canon K.K., Tokio/Tokyo Bilderzeugungssystem
FI841100A0 (fi) * 1984-03-19 1984-03-19 Kone Oy Foerfarande och anordning foer inbromsning av rulltrappor.
JPS631683A (ja) * 1986-06-20 1988-01-06 株式会社日立製作所 流体圧エレベ−タ

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2403125A (en) * 1944-10-04 1946-07-02 Westinghouse Electric Corp Control system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1155221B (de) * 1959-06-30 1963-10-03 Coelner Elektromotorenfabrik J Verfahren und Einrichtung zur Steuerung des Bremsvorganges eines Aufzugmotors
AT234955B (de) * 1961-11-09 1964-08-10 Freissler Ingenieur Maschinen Steuerung für Aufzüge mit polumschaltbarem Motor zur Erzielung möglichst kurzer Einfahrzeiten
AT248057B (de) * 1962-03-20 1966-07-11 Loher & Soehne Gmbh Steuereinrichtung zur lastabhängigen Veränderung des Abschaltzeitpunktes von Aufzügen
DE1298689B (de) * 1966-03-21 1969-07-03 Loher & Soehne Gmbh Regelbarer Antrieb fuer Aufzuege
JPS4815498B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1968-09-16 1973-05-15
GB1315589A (en) * 1970-01-21 1973-05-02 Hitachi Ltd Control apparatus for an elevator car

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2403125A (en) * 1944-10-04 1946-07-02 Westinghouse Electric Corp Control system

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4083431A (en) * 1975-05-09 1978-04-11 Hitachi, Ltd. Elevator control apparatus
US4181197A (en) * 1977-04-15 1980-01-01 Mitsubishi Denki Kabushiki Kaisha AC elevator speed control system
US4319665A (en) * 1979-05-11 1982-03-16 Hitachi, Ltd. AC Elevator control system
US4499972A (en) * 1981-03-04 1985-02-19 Elevator Gmbh Speed control system for a motor with short-circuited rotor
US4700811A (en) * 1985-03-25 1987-10-20 Sarl Logilift Method for the regulated control of a moving body carrying a variable load
US6029951A (en) * 1998-07-24 2000-02-29 Varco International, Inc. Control system for drawworks operations
US6318505B1 (en) * 1999-06-25 2001-11-20 Inventio Ag Device and method for preventing vertical displacements and vertical vibrations of the load carrying means of vertical conveyors
US20040085034A1 (en) * 2002-11-01 2004-05-06 Kuras Brian D. System and method for controlling a motor
EP1464611A3 (de) * 2003-03-31 2004-12-08 Demag Cranes & Components GmbH Verfahren zur Laufberuhigung einer Gliederkette eines Kettenzuges, insbesondere zur Verhinderung der Ausbildung einer Resonanzschwingung der Gliederkette, und einen Kettenzug hierfür
US20050110451A1 (en) * 2003-03-31 2005-05-26 Eberhard Schroder Method for stabilizing the movement of an articulated chain of a chain block, especially to prevent the formation of a resonance oscillation of the chain, and a chain block apparatus
US7026780B2 (en) 2003-03-31 2006-04-11 Demag Cranes & Components Gmbh Method for stabilizing the movement of an articulated chain of a chain block, especially to prevent the formation of a resonance oscillation of the chain, and a chain block apparatus
US20100318360A1 (en) * 2009-06-10 2010-12-16 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for extracting messages
US8452599B2 (en) 2009-06-10 2013-05-28 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for extracting messages
US8269616B2 (en) 2009-07-16 2012-09-18 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for detecting gaps between objects
US20110012718A1 (en) * 2009-07-16 2011-01-20 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for detecting gaps between objects
CN102482049B (zh) * 2009-09-09 2014-01-29 三菱电机株式会社 电梯控制装置
US20110091311A1 (en) * 2009-10-19 2011-04-21 Toyota Motor Engineering & Manufacturing North America High efficiency turbine system
US8405722B2 (en) 2009-12-18 2013-03-26 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for describing and organizing image data
US8237792B2 (en) 2009-12-18 2012-08-07 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for describing and organizing image data
US20110153617A1 (en) * 2009-12-18 2011-06-23 Toyota Motor Engineering & Manufacturing North America, Inc. Method and system for describing and organizing image data
CN101844715A (zh) * 2010-06-11 2010-09-29 日立电梯（中国）有限公司 新型电梯制动器控制系统
CN101844715B (zh) * 2010-06-11 2013-07-10 日立电梯（中国）有限公司 新型电梯制动器控制系统
US8424621B2 (en) 2010-07-23 2013-04-23 Toyota Motor Engineering & Manufacturing North America, Inc. Omni traction wheel system and methods of operating the same
US20170057782A1 (en) * 2014-02-19 2017-03-02 Otis Elevator Company Improved elevator releveling control
WO2017001884A1 (en) * 2015-07-01 2017-01-05 Otis Elevator Company Monitored braking blocks
US10654683B2 (en) 2015-07-01 2020-05-19 Otis Elevator Company Monitored braking blocks

Also Published As

Publication number Publication date
HK40177A (en) 1977-08-05
AU6484074A (en) 1975-07-24
GB1456434A (en) 1976-11-24
JPS5417219B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1979-06-28
DE2403204B2 (de) 1979-01-25
DE2403204C3 (de) 1982-10-07
CA1019480A (en) 1977-10-18
DE2403204A1 (de) 1974-08-01
BR7400484D0 (pt) 1974-10-29
JPS4996440A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-09-12
AU466364B2 (en) 1975-10-30

Similar Documents

Publication Publication Date Title
US3918552A (en) Elevator control system
US3774729A (en) Speed pattern generator for elevator systems
US4094385A (en) Levelling apparatus for AC elevator
US4319665A (en) AC Elevator control system
US3687235A (en) Control apparatus for an elevator car
EP0074093B1 (en) Controller for elevator
JPS6260352B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
US4441584A (en) AC Elevator control system
US4491197A (en) Speed control apparatus for A.C. elevator car drive motor
US3442352A (en) Elevator control system
US3552524A (en) Speed dictation apparatus for elevator motor control system
US4661757A (en) Controller for AC elevator
US4213517A (en) Elevator control system
US4122919A (en) Speed control apparatus for AC elevator
US4235309A (en) Control for starting electric motors
GB2050984A (en) Variable speed passenger transit device
US3759350A (en) Elevator system
US3516518A (en) Elevator control system
JPS5844592B2 (ja) エレベ−タセイギヨホウシキ
US1503245A (en) Motor controller
JPS6359945B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
US1725772A (en) Electric elevator system
US3448364A (en) Elevator motor control system including dynamic braking with motor field excitation
US2528126A (en) Variable voltage motor control system
JPS6316690Y2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)