US3670851A

US3670851A - Speed pattern generator for elevator control system

Info

Publication number: US3670851A
Application number: US75171A
Authority: US
Inventors: Seiya Shima
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1969-09-29
Filing date: 1970-09-24
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20
Also published as: FR2062707A5; CA918271A; DE2047681A1; DE2047681B2; JPS5018260B1

Abstract

A speed pattern generator for an elevator control system generating an accelerating speed pattern with is a function of time and increases monotonously, a decelerating speed pattern which is a function of the distance between the elevator and the desired floor level and decreases monotonously, and a compensating speed pattern which is a function of the difference between the accelerating speed pattern and the decelerating speed pattern and decreases monotonously so that the compensating speed pattern ensures a smooth transition from the accelerating speed pattern to the decelerating speed pattern.

Description

United States Patent Shima [4 1 June 20, 1972 s41 SPEED PATTERN GENERATOR FOR 3,350,612 l0/l967 Hansen et a]. ..318/l43 ELEVATOR CONTROL SYSTEM 3,526,300 9/1970 Ferrot 187/29 [72] Inventor: Seiya Shlma, Katsuta, Japan a ExaWm, Hm-|d Broome Assistant Examiner-W. E. Duncanson, .l r. [73] Asslgnee. Hitachl, Ltd., Tokyo, Japan Ana g Amend & Hm [22] Filed: Sept. 24, 1970 ABSTRACT [2|] Appl. No.1 75,17l

A speed pattern generator for an elevator control system generating an accelerating speed pattern with is a function of F Allllliclfioll time and increases monotonously, a decelerating speed pattern which is a function of the distance between the elevator Sept. 29, 1969 Japan ..44/76938 and the desired floor level and decreases monotonously and a compensating speed pattern which is a function of the dif- [52] 0.8. CI. ..l87/29R ference between the accelerating speed pattern and the [51] Int. Cl "866) 1/28 decelerating speed panel." and decreases monotonously so 58] Field of Search 1 87/29; 318/143, 448, 449, that the compensating speed pane", ensures a smooth p 318/611 tion from the accelerating speed pattern to the decelerating speed pattern. [56] References Cited 5 Chins, 12 Drawing Figures UNITED STATES PATENTS 3,523,232 8/1970 Hall et al l87/29 X 15 REX-Em S/G/VAL FU/VCWO/V Gilli-774 ACTUAL SP PATT PATENTEDwuao m2 SHEET 10F 5 I 3 \GRADIENT fi emu/amp i Ke '1 v F T m m 5 R m m 6 E W INVENTOR SEW A SHIMA BY Cmi nnlionelLL SLemwL w Hill ATTORNEYS PATENTEnJunzo m2 SHEET 3 0F 5 FIG. 40

lzyvzsmon SEWA SHIMA BY Cmia, lnlmem, Shqtprlf ATTORN E Y5 PliTENTEnJunzo m2 SHEET q BF 5 mmmqm emtwmmduuw INVENTOR SEPIA SHIMA BY CYah nntonelli, 5heworkHU ATTORNEYS MTENTEDJUHZO :272 3, 670 851 SHEET 5 BF 5 h A m 3; Q: R

FIG. 8

INVENTOR Jaw/A SH'IMA BY Antonellm, ShemcrL L H411 ATTORNEYS SPEED PA'I'IERN GENERATOR FOR ELEVATOR CONTROL SYSTEM This invention relates to improvements in a speed pattern generator for an elevator control system.

A comfortable ride is demanded for elevators carrying passengers. To meet this demand, it is desirable that the speed pattern supplied to the speed control system for an elevator increases monotonously as a function of time during acceleration until the elevator speed reaches the rated speed and the rated speed is maintained for a certain period of time thereafter (or the speed may be immediately decreased), while during deceleration, the speed pattern is a function of the distance or deceleration distance between the elevator and the desired floor level and decreases monotonously with the decrease in the deceleration distance.

A speed pattern generator for an elevator control system commonly presently in use comprises means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance between the elevator and the desired floor level, and decreases monotonously, and a circuit having a time lag of first order for ensuring a smooth transition from the accelerating speed pattern to the decelerating speed pattern. However the prior art speed pattern generator has been defective in that the accuracy of the actual speed pattern generated thereby is quite low due to the provision of the time lag circuit therein.

It is therefore a primary object of the present invention to provide an improved speed pattern generator which can minimize the rate of variation of acceleration without employing a circuit having a time lag of first order and yet shows a high leveling accuracy.

The above and other objects, features and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. la is a graph showing an ideal speed curve for an elevator;

FIG. lb is a graph showing an ideal acceleration curve for the elevator driven according to the ideal speed pattern shown in FIG. Ia;

FIG. "2 is a block diagram showing the basis structure of means for generating an accelerating speed pattern;

FIGS. 30 and 3b are graphs showing a speed and an acceleration curve, respectively, in an elevator equipped with a prior art speed pattern generator;

FIGS. 44 and 4b are graphs showing a speed and an acceleration curve, respectively, representing a first speed pattern obtained by a speed pattern generator according to the present invention;

FIGS. 5a and 5b are graphs showing a speed and an acceleration curve, respectively, representing a second speed pattern obtained by the speed pattern generator according to the present invention;

FIG. 6 is a block diagram of an embodiment of the present invention;

FIG. 7 is a diagram of a relay circuit employed in the embodiment shown in FIG. 6; and

FIG. 8 is a graphic representation of the first and second speed patterns.

The acceleration a m/sec and the rate of variation of acceleration B m/sec in an elevator have their limits in order that man riding in the elevator feels a comfortable sense of ride. These limits are designated herein by a, m/sec' and B, m/sec", respectively.

FIGS. 1a and lb show an ideal speed curve and an ideal acceleration curve, respectively, taken as a function of time in the case of the maximum acceleration a, mlsec and maximum rate of variation of acceleration B, m/sec. In FIG. 1a, the horizontal and vertical axes represent the time and the speed, respectively, while in FIG. lb, the horizontal and vertical aiies represent the time and the acceleration, respectively.

The ideal speed curve and the ideal acceleration curve shown in FIGS. la and lb will now be discussed in detail. In

the range of from time 0 to t, (hereinafter to be referred to as mode I), the acceleration is increased linearly and the rate of variation of acceleration is maintained at the constant value 8,. In the range of from time t, to t, (hereinafter to be referred to as mode 2), the acceleration is maintained at the constant value a, and the rate of variation of acceleration is zero. In the range of from time t, to r, (hereinafter to be referred to as mode 3), the acceleration is decreased linearly and the rate of variation of acceleration is maintained at the constant value -B,. Throughout these ranges, the elevator is accelerated.

In the range of from time I, to t, (hereinafler to be referred to as mode 4), the elevator is driven at the rated speed V, In the range of from time I, to r (hereinalter to be referred to as mode 5), the acceleration is increased in the negative direction and the rate of variation of acceleration is maintained at B,. In the range of from time I, to t. (hereinafier to be referred to as mode 6), the acceleration is maintained at -a,. 1n the range of from time t. to r, (hereinafter to be referred to as mode 7), the rate of variation of acceleration is maintained at 5,. Throughout these ranges, the elevator is decelerated.

The speed pattern described above is classified into a first speed pattern which does not include the mode 4 and a second speed pattern which includes the mode 4. The first speed pattern is generated when the distance between the floor level at which the elevator is presently at rest and the desired floor level to be reached by the elevator is shorter than the distance required for the acceleration and deceleration of the elevator according to the speed pattern shown in FIGS. 10 and lb, that is, the distance run by the elevator during the period of from time 0 to t, and from time t, to The second speed pattern is generated when the distance between the floor level at which the elevator is presently at rest and the desired floor level to be reached by the elevator is longer than the distance required for the acceleration and deceleration of the elevator according to the speed pattern shown in FIGS. la and lb. Theoretically, there may be a third speed pattern which does not include the

modes

2, 4 and 6. However, when the maximum allowable acceleration a, is set at l mlsec and the maximum rate of variation of acceleration B, is set at l m/svec according to common practice, the running distance of the elevator according to the third speed pattern must be less than 2.3 m, whereas the minimum distance between the adjacent floor levels is commonly of the order of 2.6 m. Thus, the third speed pattern is not considered herein because the third speed pattern is not generated during normal operation.

An accelerating speed pattern V for the

modes

1 and 2 is generated by a function generator so that it is a function of time 1' seconds lapsed after the elevator is started at time 1 =0. More precisely, in the range I t, (r, corresponding to t, in FIGS. 10 and lb), the accelerating speed pattern V, for the mode I can be obtained by generating a function V,,=%B,r* (m/sec) l by integrating the rate of variation of acceleration B, with tim'la theraqgg 151,, the acceleratingggeelpartem y i'or the mode 2 can be obtained by generating a function V, 01,: V, (m/sec) 2 Further, t, and V, are given by the following equations:

W 3 slB. (In/ 4 The equation (4) can be obtained by substituting tin the equation (I) by r, in the equation (3). Referring to FIG. 2, the output from a function generator FG generating a saturated ramp function may be applied to and integrated by an integrator IG with time to obtain the accelerating speed pattern described above.

A decelerating speed pattern V, for the modes 6 and '7 can be obtained by generating a function which includes a parameter L which is the deceleration distance in meters. More precisely, a function Mtle precisely, the deceleration distance l jiie xpressed as may be generated in the range of from time I, to t, where L L, The point L, in distance in the above equations (5) and (6) is determined by the maximum acceleration a, and the maximum rate of variation of acceleration and deceleration a, and l is given by e s 3s 7 The equations (5) and (6) giving the decelerating speed pattern V, are determined in a manner as described below. Suppose that the elevator is brought to a halt at time t I 0, then the decelerating speed pattern V, may be obtained by replacing the time t in the equations (1) and (2) by -t. Thus, the decelerating speed pattern V, can be expressed as b Bl t 8 when 1T} 5n, and as when, .1 I w sesssvsas iizfi rjliliw the equation (8) with time, the deceleration distance Lisgiven by when Ill t,. From the equafims (8) and (10), the actual speed pat t e rn V can be expressed as a function of the deceleration distance L as follows:

V= A3. (6 /BJ 11 On the other hand, when hi a, the deceleration distance L is given by where L, represents the deceleration distance when t :,l and is given by L, 1/6 ,6, r, 1/6 113/3, 13 i From the above equations, the actual speed pattern V can be expressed as a function of the deceleration distance L as fol- I lows:

The decelerating speed pattern V, is sought from the above equation as b= 2mi 14m The above function c an be ob tained by coh tinuously detecting the deceleration distance L and operating the function generator. It will be apparent that the speed pattern supplied to the speed control system for the elevator can ensure a comfortable sense of ride if the accelerating speed pattern represented by the equations (1) and (2) makes a smooth transition to the decelerating speed pattern represented by the equations (5 and (6).

FIG. 3a shows the speed curve obtained as a result of the above calculation, in which the accelerating speed pattern V, the decelerating speed pattern V, and the rated speed V, are shown by broken lines, while the actual speed pattern V is shown by the solid lines. FIG. 3b shows the corresponding ac celeration curve. It will be seen from FIG. 31:: that the speed pattern does not include the

modes

3 and 5 unlike the speed pattern shown in FIG. 10. Due to the absence of the

modes

3 and 5, the rate of variation of acceleration and deceleration is quite great at a point r, where the speed reaches the rated ing speed pattern V, and the decelerating speed pattern V, is smaller than 4 V, or V,- V, 4V,, the compensating speed pat- 4b, the actual speed pattern V starts to decrease at time t, at

which the decelerating speed pattern V, intersects the accelerating speed pattern V,. Therefore, the left-hand and ri t-hand sections of the actual speed pattern V is symmetriexternal disturbance. In another attempt which has been made heretofore, a function of time as shown in FIG. lb is applied to an integrator so as to derive an ideal speed pattern as shown in FIG. In from the output of the integrator. However, the speed pattern in this case is a function of time throughout the acceleration and deceleration regions. This method has therefore been defective in that the decelerating speed pattern is not related with the position of the elevator and thus the elevator cannot accurately stop at the desired floor level.

FIGS. 40 and 4b and FIGS. 50 and 5b show two kinds of speed patterns generated by a speed pattern generator of the present invention. FIGS. 4:: and 4b show a first speed pattern which does not include the mode 4, while FIGS. 54 and 5!: show a second speed pattern which includes the mode 4.

Referring to FIG. 4a, the symbols V, and V, designate the accelerating speed pattern given by the equations (1) and 2) and the decelerating speed pattern given by the equations 5) and (6), respectively. According to the present invention, the actual speed pattern V coincides with the accelerating speed pattern V, in the range in which the diiference between the accelerating speed pattern V, and the decelerating speed pattern V, is greater than 4 V,, that is, V,-V, 4V,. This range corresponds to the

modes

1 and 2 in FIG. la. The speed pattern V according to the present invention will be discussed in more detail below. The difference in time a) between time t, at which the acceleration starts to decrease and time I, at which the acceleration becomes zero is equal to a period of time t, during which the acceleration is increased from zero to the maximum value a, as will be apparent from FIG. 4b. (This is quite natural since the rate of variation of acceleration B, is the same in both ranges.) Since the gradient of the accelerating speed pattern V, is 02,, the difference between the value of the accelerating speed pattern V, at time t, at which the accelerating speed pattern V, intersects the decelerating speed pattern V, as shown in FIG. 4a and the value of the accelerating speed pattern V, at time t, at which the acceleration starts to decrease as shown in FIG. 4b is given by .=/p.= 2 v. 14 Due to the fact that the decelerating speed pattern V, and the accelerating speed pattern V, have the same gradient of opposite sign, the difierence between the two speed patterns at time t, is given by V,-V, 4V,. Thus, the actual speed pattern V shown in FIG. 4a may be generated in such a manner that the acceleration starts to decrease when V,-V, 4V and is decreased to zero when the accelerating speed pattern V, intersects the decelerating speed pattern V,.

In the range in which the difference between the decelerating speed pattern V, and the accelerating speed pattern V, is decreased to an extent that V,-V, 4V a compensating speed pattern V, is generated and the difference between the accelerating speed pattern V, and the compensating speed pattern V, or V,-V, is utilized as the actual speed pattern for such a range. This range corresponds to the mode 3 in FIG. 1a.

In the deceleration region, the accelerating speed pattern V, is greater than the decelerating speed pattern V,. In the range in which the difference between the accelerating speed pattern V, and the decelerating speed pattern V, is greater than 4V, or V,-V, 4V,, the actual speed pattern V coincides with the decelerating speed pattern V,. This range corresponds to the modes 6 and 7 in FIG. la.

In the range in which the difference between the accelerattem V, is generated as in the case of the acceleration so that the difi'erence between the decelerating speed pattern V, and the compensating speed pattern V, or V,V, is utilized as the speed V. and at a point t, where the sp eed starts to reduce from the rated speed V, as seen in FIG. 36. An attempt has been made to reduce the rate of variation of acceleration and deceleration by supplying the speed pattern to the elevator speed control system through a circuit having a time lag of first order. However, this method has been defective in that the p esence of the time lag circuit results in a large degree of cal about time 1, due to the fact that the rate of variation of tic celeration is the same in both the sections. Thus, the actual speed pattern V during the deceleration may be selected as in the case of acceleration depending on whether the diiference V,V, between the decelerating speed pattern V, and the accelerating speed pattern V, is larger or smaller that 4 V,.

The compensating speed pattern V, used in the

modes

3 and 5 is obtained in a manner as described below. The difference AV between the accelerating speed pattern V, and the actual speed pattern V in the range in which the acceleration is decreased linearly as shown in FIG. 4b and the actual speed pattern V is increased smoothly as shown in FIG. 40 can be obtained by calculating the area of the hatched portion in FIG. 4b. The difference AV is given by On the other hand, the following equation holds due to the 1 fact that the gradient of the accelerating speed pattern V, is a, and the gradient of the decelerating speed pattern V, is oz,: 1 l6 actual speed pattern V for the mode 3 is givenby Similarly, the actual speed pattern Vfor the mode 5 is given by V= V,V,=V,(4V,+V,V,)*/16 19 FIGS. 50 and 5b show a second speed pattern which includes the mode 4. in this case, the circumstances are quite difi'erent from those shown in FIGS. and 4b because the I second speed pattern includes a portion corresponding to the rated speed and therefore it is insignificant to decrease the ac- ]celeration to zero at a point at which the accelerating speed pattern V, intersects the decelerating speed pattern V,. As will be apparent from FIG. 5a, the value of the accelerating speed pattern V, at time t, where the rated speed V, is reached is given by V,=V,V,+2V,=V,+V, 20 According to the present invention, the speed V, V, is taken as a reference and the actual speed pattern V coincides with the accelerating speed pattern V, when V, V, V, 2V,, that is, Va V, V,. The speed enters the mode 3 when the value of the accelerating speed pattern V, attains the level of V, V, at time I, even when a difference of greater than 4V 1 exists between the accelerating speed pattern V, and the decelerating speed pattern V, or V, V, 4V,.. In this mode 3, a smooth transition to the rated speed V, cannot be carried out unless the acceleration is decreased. Accordingly, the value obtained by subtracting AV given by the equation (l5) from V, must be taken as the actual speed pattern Vwhen the difference between the accelerating speed pattern V, and the decelerating speed pattern V, is greater than 4V, or V, V, 4V, at the time at which the value of the accelerating speed pattern V, attains the level of V, V, On the other hand, the following equation holds in this case:

r' s r" a) r rr a 's) .fmmt lsq fiaratl n (2 ma i .5815. x.

Accordingly, the actual speed pattern V in this range is given y V= V, V, V, (V, V, V,)'/4V, 23 in the range in which the values of both the speed patterns V, and V, are greater than V, V,, the mode 4 appears and the actual speed pattern V in this range coincides with the rated speed V,. The mode 5 appears in the range in which the value of the decelerating speed pattern V, is smaller than V, V,. The actual speed pattern Vin this range is given by v= V, v, V,-(V,.+ v.- mvsv, as in the case ofthe mode 3.

FIG. 6 is a block diagram of an embodiment of the present invention for generating the ideal speed pattern described above. and FIG. 7 is a diagram of a relay circuit employed in the embodiment shown in FIG. 6.

Referring to FIG. 6, an accelerating speed pattern generatlng means i generates accelerating speed patterns V,. and V, which are the functions of time given by the equations l and (2). Thus, V,, and V,. are given by at BI n! s e A decelerating speed pattern generating means 2 generates decelerating speed patterns V, and V, which are the functions of time given by the equations (5) and (6). Thus, V, and V,, are given by lE Q ii) .T.

bower level priority means 3 and 4 are adapted to deliver an output which corresponds to an input of the lower level between two inputs applied thereto, and

adders

5, 6, 8 and 12 add two inputs applied thereto. A full-wave rectifier 7 delivers an output which is the absolute value of an input signal applied thereto, and diodes 9 and i3 block the passage of a negative signal. A function generator 10 generates an output corresponding to a function (l/l6) (1/V,) x in response to an input signal 1. A reference signal generating means ll generates a reference signal representative of V, V,. An amplifier l4 acts to double the signal delivered from the adder 12. Another reference signal generating means 15 generates a reference signal representative of 4V,. A relay A shown in FIG. 7 has make contacts A, and A, and a break contact A,

The system shown in FIG. 6 generates the first speed pattern in a manner as described below. It will be apparent from the descripu'on given with reference to FIGS. 40 and 4!) that, in the case of the first speed pattern, the difi'erence V, V, between the decelerating speed pattern V, and the accelerating speed pattern V, becomes smaller than 4V, before the value of the accelerating speed pattern V, attains the level of V, V, In this case, the break contact A, of the relay A is in its closed position since the relay A is decnergized. in response to the starting of the elevator, the value of the accelerating speed pattern V, is successively increased. However, in the

modes

1 and 2 in which the difference between the decelerating speed pattern V, and the accelerating speed pattern V, is larger than 4V, or V, V, 4V,, the output from the fullwave rectifier 7 is larger than 4V, and no output is delivered from the diode rectifier 9, hence no output is delivered from the function generator 10.

In the meantime, the lower level priority means 3 and 4 select the accelerating speed pattern V, so that the accelerating speed pattern V, appears at the output of the system. When the value of V, V, becomes smaller than 4V, as the value of the accelerating speed pattern V, is further increased,

the adder 8 delivers an output representative of 4V, IV,

V,| and the function generator 10 delivers an output representative of (l/l6) (l/V,) (4V, IV. VJ). Since the Tower level priorit y means 3 and 4 select nie'sriilir'bne ofthe accelerating speed pattern V, and the decelerating speed pattern V,, the actual speed pattern V appearing at the output of the system is represented by a value obtained by subtracting (Hi6) (l V.) (14V, l V,, V from the smaller one of V.

and V,. Asthe value of the accelerating speed pattern V,, is further increased until it becomes larger than V 4 V,, no output is delivered from the diode rectifier 9, and the lower level priority means 3 and 4 now select the decelerating speed pattern V, so that the decelerating speed pattern V appears at the output of the system as the actual speed pattern V.

The system shown in H6. 6 generates the second speed pat tern in a manner as described below. The operation of the system is the same as the case of the first speed pattern in the ranges in which the value of the accelerating speed pattern V,, is smaller than V, V,. In the case of the second speed pattern, the relay A is energized to open the break contact A, and close the make contact A when the value of the accelerating speed pattern V, attains the level of V, V, and yet the difference V, V,, between the decelerating speed pattern V, and the accelerating speed pattern V,, is larger than 4V,.

The relay A is combined with relays B (not shown) and C (not shown) which are connected to the output side of the diode rectifier 9 and to the output side of the accelerating speed pattern generating means 1, respectively, so as to constitute a circuit as shown in FIG. 7. The relay B has a contact B, which is closed in response to the appearance of an output from the diode rectifier 9 and holds itself. The relay C has a contact C which is momentarily closed when V V, V, and is then urged to its open position again. The relay A is connected to a power supply through

terminals

16 and 17. Thus, the relay A is energized when V V. V, and the contact B is in its closed position due to V, V, 4 V,. The relays A and B are released from their self-holding state in response to the stoppage of the elevator at the desired floor. Thus, the mode 3 is started when the relay A is energized and is ended when V,, equals V V,. The accelerating speed pattern V,, is selected by the lower level priority means 3 and 4 and the amplifier l4 delivers an output representative of 2( V, V, V Consequently, the comparator 8 delivers an output representative of 2(V, V, V,) and the function generator 10 delivers an output representative of (V4) (1/V,) (V, V VJ. Therefore, the actual speed pattern V appearing at the output of the system is represented by V,, (V4) (l/V,) (V, V,, V,). The mode 4 begins when the values of both the accelerating speed pattern V, and the decelerating speed pattern V,, are larger than V, V,. in this case, the lower level priority means 4 delivers an output representative of V, V, and a negative output is delivered from the comparator l2. Thus, no output is delivered from the diode rectifier l3 and the comparator 8 delivers an output representative of 4V, with the result that the function generator It) delivers an output representative of V, and the actual speed pattern V appearing at the output of the system is represented by the rated speed V,. In the range in which V, V, V,, V, V,, that is, in the mode 6, the operation of the system is similar to that in the case of the mode 4 so that the actual speed pattern V appearing at the output of the system is now represented by V, '/4)( l/V,) (V, V, V,)'. In the range in which V, V. V,, that is, in the mode 7, the output from the comparator 12 is larger than 2 V, and the output from the amplifier 14 is larger than 4V, with the result that no output is delivered from the diode rectifier 9. in this range, the lower level priority means 3 and 4 select the decelerating speed pattern V, and thus the actual speed pattern V appearing at the output of the system is represented by the decelerating speed pattern V,,

In the embodiment described above by way of example, the rate of variation of acceleration is kept constant and the compensating speed pattern V is supplied when the difference between the accelerating speed pattern V and the decelerating speed pattern is equal to 4V,. However, these values may be suitably varied within a certain range. The same applies also to the compensating speed pattern V,'.

FIG. 8 shows a plurality of first speed patterns P through P, and a second speed pattern P generated by the system according to the present invention. it will be seen from FIG. 8 that the speed of the elevator during deceleration is variable depending on the relative distance between the floor level at which the elevator is at rest and the desired floor level in the case of the first speed pattern.

What is claimed is:

l. A speed pattern generator for an elevator control system comprising means for generating a monotonously increasing accelerating speed pattern, means for generating a decelerating speed pattern which is a function of the distance between the elevator and the desired floor level, and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between said accelerating speed pattern and said decelerating speed pattern and decreases monotonously, wherein said accelerating speed pattern or said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is larger than a predetermined setting, while the value obtained by subtracting said compensating speed pattern from said accelerating speed pattern or said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is smaller than the predetermined setting.

2. A speed pattern generator for an elevator control system as claimed in claim 1, in which said accelerating speed pattern is a function of time.

3. A speed pattern generator for an elevator control system comprising means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance from the elevator to a floor and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between said accelerating speed pattern and said decelerating speed pattern and decreases monotonously, wherein said accelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is larger than a predetermined setting, while the value obtained by subtracting said compensating speed pattern from said accelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is smaller than the predetermined setting. 0

4. A speed pattern generator for an elevator control system comprising means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance from the elevator to a floor and decreases monotonously, and means for generating a compen sating speed pattern which is a function of the difference between said accelerating speed pattern and said decelerating speed pattern and decreases monotonously, wherein said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is larger than a predetermined setting, while the value obtained by subtracting said compensating speed pattern from said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is smaller than the predetermined setting.

5. A speed pattern generator for an elevator control system comprising means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance from the elevator to a floor and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between a first predetermined speed higher than the rated speed and said accelerating speed pattern or said decelerating speed pattern and decreases monotonously, wherein the value obtained by subtracting said compensating speed pattern from setting. while the rated speed is selected as the actual speed pattern in the range in which the values of both said accelerating speed pattern and said decelerating speed pattern are larger than the value of the first predetermined speed.

t I l I l

Claims

1. A speed pattern generator for an elevator control system comprising means for generating a monotonously increasing accelerating speed pattern, means for generating a decelerating speed pattern which is a function of the distance between the elevator and the desired floor level, and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between said accelerating speed pattern and said decelerating speed pattern and decreases monotonously, wherein said accelerating speed pattern or said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is larger than a predetermined setting, while the value obtained by subtracting said compensating speed pattern from said accelerating speed pattern or said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is smaller than the predetermined setting.

3. A speed pattern generator for an elevator control system comprising means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance from the elevator to a floor and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between said accelerating speed pattern and said decelerating speed pattern and decreases monotonously, wherein said accelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is larger than a predetermined setting, while the value obtained by subtracting said compensating speed pattern from said accelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is smaller than the predetermined setting.

4. A speed pattern generator for an elevator control system comprising means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance from the elevator to a floor and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between said accelerating speed pattern and said decelerating speed pattern and decreases monotonously, wherein said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is larger than a predetermined setting, while the value obtained by subtracting said compensating speed pattern from said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern and said decelerating speed pattern is smaller than the predetermined setting.

5. A speed pattern generator for an elevator control system comprising means for generating an accelerating speed pattern which is a function of time and increases monotonously, means for generating a decelerating speed pattern which is a function of the distance from the elevator to a floor and decreases monotonously, and means for generating a compensating speed pattern which is a function of the difference between a first predetermined speed higher than the rated speed and said accelerating speed pattern or said decelerating speed pattern and decreases monotonously, wherein the value obtained by subtracting said compensating speed pattern from the smaller one of said accelerating speed pattern and said decelerating speed pattern is selected as the actual speed pattern in the range in which the difference between said accelerating speed pattern having attained the level of a second predetermined speed lower than the rated speed and said decelerating speed pattern is not smaller than a predetermined setting, while the rated speed is selected as the actual speed pattern in the range in which the values of both said accelerating speed pattern and said decelerating speed pattern are larger than the value of the first predetermined speed.