DE1302194C2 - DEVICE FOR DETERMINING AND REGULATING THE SPEED OF A MOVING OBJECT - Google Patents

Description

Acceleration or both, the braking distances must be reset.

The increase in the speed of conveyor systems, in particular of elevators, is therefore the difficult to meet requirement that the moving object, z. B. the car, on one exactly given place comes to a standstill and there? the delay occurring as well as the Acceleration and its derivation according to the time (jerk) when starting, especially when transporting people, Do not exceed certain physiologically determined values during the braking process.

This problem of precisely stopping a conveyor at a specific point is known in and of itself. For example, it is known to automatically decelerate pulling machines to control the use of deceleration or the start of deceleration as a function of the speed of the elevator. Thus, in a known device for controlling conveyor devices, in order to start braking a movement only by the speed-dependent length of the braking distance to reach the desired rest position, two devices are provided, of which the first is to measure the driving speed or the driving time or - distance is used, while, depending on this measured variable, the second device is influenced, which is used to set the braking time or the braking point. This speed-dependent influencing is carried out, for example, by a cable which is actuated in particular as a function of the speed of the conveying device and which indicates the start of braking.

Attempts have also been made to determine the speed difference equalize using mechanical means. So is a speed-dependent one Control of the start of deceleration in elevators with drive by three-phase squirrel cage motors became known, in which a contact finger depending on the speed of the drive motor to change the slip range is adjusted. The accuracy of stopping the car at a given point is not the same here either precisely that holding without the execution of a secret path with the necessary technical Effort is possible.

These known arrangements assume that the braking distance is a function of the speed, d. that is, the hoist must be at a constant speed at the moment the deceleration begins drive.

In order to increase the stopping accuracy, electronic computers are already in the braking devices been used. A method for the electrical control of the brake of elevators has become known, in which as a control variable to regulate the force for dip braking the difference between one distance- and speed-dependent deceleration program and the current deceleration value is used, whereby the distance and speed dependent deceleration program is proportional to the Quotient from the square of the current speed divided by the distance from the stopping point is. To carry out this method, a computing device is used in which to generate a cam disk in connection with a double potentiometer for the root function required is provided.

This method of electrically controlling a brake is only capable of constant deceleration applicable. It does not take into account the smooth transition from an acceleration process or constant speed to constant deceleration at any instantaneous speed.

The speed of a train has already become known when it comes to the operation of long-distance trains To determine train for the purpose of positioning using a digital computer. Also isl the possibility of speed control using the setpoint values determined in this way where the speed setpoint is a Train corresponds to a travel curve which corresponds to the specified values of speed and deceleration complies, the possible breakpoint is determined by the fact that the correct brake application as Intersection of a simulated braking parabola mil

the load speed of the train results. Here, however, punched tape can be used to simulate, and there is no permanent, independent Calculating ^r travel curve instead.
It is also a digital control device

Shaft hoisting machine became known at dei regardless of the status of a target value counter, a digital-to-analog converter generates an analog target value for the speed control of the hoisting machine.

Contrary to what is known, the object of the present invention is to provide a Device for regulating a drive of a moving object, in particular the regulation of the dei Distance traveled by this object

Way, underlying, being the scheme, indifferent whether it is long stretches or short stretches, at a maximum and optimal speed is carried out without control-related switching operations by z. B. Initiators

which so far on the covered by the moved object Distance are provided, must be triggered. That is, with the subject of the enclosed Invention is eliminated with the omission of all outside of the actual control device

Auxiliary devices such as initiators, control contacts and the like, a precise adjustment of a given Distance reached.

Based on a device for determining and regulating the speed of a moving

Object for the purpose of positioning using a digital computer with digital-to-analog conversion of the controlled variables with numerical target specification, whereby the speed value of the moved object corresponds to a travel curve.

which the digitally specified values of acceleration change (jerk), acceleration and speed complies with and where the delay if the possible breakpoint coincides with the target point is initiated, the invention consists in

that the possible stopping point of the moving object is determined continuously and independently of the calculation of the travel curve and a Wcgregulation ensures that the drive follows the target travel curve on which the calculation of the stopping point is based.
The possible stopping point of the moving object is preferably calculated using two integrators. It is foreseen. that the overeanc from the acceleration

of the moving object to the maximum speed, the transition from the maximum speed of the moving object on the deceleration or the transition from the acceleration of the moving Subject immediately to the delay in a smoothed way.

Due to the digital path recording, an extremely high level of accuracy can be achieved, which only depends on the pulse sequence in the unit of time. There are practically no limits to the pulse sequence set so that the accuracy can be driven very high without significant effort.

The digital results obtained in this way are converted into analog values in order to carry out the control. So it will be the high accuracy of digit integration based on digital path recording achieved in combination with the advantages of analog control.

The starting point of the braking process is included with a specified distance to be covered predetermined acceleration and braking process continuously calculated. The braking comes here the point in time from which on, given the course of the travel curve (acceleration, Maximum speed, delays and their derivatives according to time) the braking distance and the up to The distance covered at this point in time of the use of the brake corresponds to the specified distance. the possible stopping point is the sum of the distance covered so far and the braking distance of the current one Driving condition.

Precise positioning is therefore achieved in a minimum of time with a free path specification without creep speed and when a certain defined course of the travel curve Vf (t) is adhered to. The formation of the device ³⁵ is such that the change in acceleration and the limit values for the acceleration (deceleration) and the speed be set numerically with the application of a digital computer.

It is also possible here to set asymmetrical travel curves by setting separately To get acceleration and deceleration.

The mode of operation is such that, through integration, the setpoints for the position control are included of the subordinate analog speed control loop of the drive is calculated.

During operation, the drive is accelerated until the sum of the distance covered and the pre-calculated braking distance equals the specified distance or until the machine has reached its maximum speed. The computing device works accordingly continuously. In this case, the specified target value for the deceleration during the braking process must match the deceleration value that was used for the precalculation of the braking distance. In contrast to analogue setpoint generators, this is the case with digital setpoint generators regardless of external influences. It is thus possible to stop the driven object, such as a ^ ⁰ reel, the rollers of braking frames, the cabin of elevators and the like at a certain predetermined point by continuously monitoring the course of the travel curve by means of the computer, whereby to Any * ⁵ distance with a given acceleration and deceleration (which can also be different from each other) the shortest adjustment or travel time is achieved. This is possible in the case of passenger elevators, provided certain acceleration and braking conditions are observed, ζ. Β. while maintaining a certain driving comfort.

A variant of this possible solution is based on the desired target point and subtracts the braking distance from the target position. The braking process is initiated by the computer when this difference corresponds to the current position of the system.

The invention is shown in FIGS. 1 to 5 shown for example on a position control. Here, FIG. 1 the scheme of a digital path control with digit integrators.

The speed and direction of rotation controlled by the servo amplifier 14 Motor 16 for the drive, e.g. B. a roll of a roll stand drives the tachometer generator 18 and a pulse generator 20.

The signals generated by the pulse generator 20 are fed to the counter 22, while the combination device 24 is fed the actual value of the speed V ₁₅ , as a negative signal and as positive signals via the digital-to-analog converter 28 the value of the path control deviation 1 s. This value Is corresponds to the difference between the predetermined distance s _so "and the distance covered by the positioning roller s _isl . This value is fed to the digital-to-analog converter 28 as a digital signal from the subtracter 30. The predetermined, zurückzulegende for example, the distance Anstellwalze 5 _{7i (;} is set by the target position encoder 32 and set on this.

The set value s _{iI> (} is fed to a comparison device 34. A signal s _ha " , which is output by the integrating device 36, is also fed to this comparison device

The signal emitted by the comparator 34 is fed to the control unit 38 for the limit values, such as starting acceleration and deceleration when braking. The signals emitted by the control unit 3i8 are V _h0 = initial value of the speed for calculating the possible stopping point of the positioning roller, b _h = acceleration value for calculating the possible stopping point and b ' = change in acceleration. They are fed to the integrator 40, while the output of this integrator 40 is fed to the input of the integrator 36 during the acceleration process.

The value b ′ of the control unit 38 is fed to the integrator 42 and from there to the integrator 44. Its output is input to the integrator 36 to form the signal s _halt during adjustment at constant speed and is also fed to the digital-to-analog converter 26 to form the setpoint speed _signal v mtl. The integrator 46, the output of which is input to the subtracting device 30, also receives the same signal.

As shown in FIG. 1, all values or signals with the exception of the signal for the speed Vj _{x of} the tachometer generator 18 are used as digital values, which are converted back into analog values for the control of the motor 16 via the digital-to-analog converters 26, 28.

The principle of digit integration is how out the F i g. 1 and the explanations relating to it can be used for the control of mechanical movements

especially advantageous. Such movements are, for example in a simplified manner, assigned to the constant surface 2 'and 4' described by the following equations: be summarized. Area 1 is used as an area-

/ same rectangle 1 'adopted, one side of which

i · · d; length is equal to the acceleration time t _h . The three-

- ⁵ corner surface 3 is converted into a rectangular

c =!>"+ Ib ■ d (Iige triangle converted, one side of which

J corresponds to the acceleration time t _v. The integration

/, _ /, + Γ ^ b _ j then takes place over time with s = Jt'df, whereby one

"J dr 'receives the path during the deceleration walk.

... ¹⁰ In the diagram according to FIG. 4 the integration takes place

It is therefore advantageous to use _{digit integrators tjon over} " _{according to the} relationship s = frd". Searched

used because analog electronic integrators _{are again the} area below curve 5,

To solve such equations, the accuracy _{6 7 Here, too,} surfaces 2 and 4 become one

wedge result, which summarized for the operation of control systems, _constant area 2 ', 4. the

like Haspcl, conveyor systems, with the 15 _F , area _{attached to them} , _{results from the expression c} . | _{dl ,? where} _

high demands on speed and accuracy _{bej c dje dj men} sion of a time. The triangle 6, 9,

wedge are required. The limit of the relative Oe 10 is equal in area to _{the triangle 6 8] 0.} These three-

nauigkcil of analog computers with economical _lv . _υ

Effort is about 0.5% of the final value, that is corner area 6, 8,! 0 is F = -γ ~, where

in the case of an elevator with a travel path of z. B. 20

100 m already 50 cm. In addition, with such _ j r

Do not calculate the result of an integration over ^ft "- ^" J ^dr
save longer line spaces.

Digital computers or special digit inserters

can solve the above equations. 25 _sl j oj _e g _esa mte surface 3 is then obtained to
if one replaces the integrals with sums Then
the following equations result:

..:., v = V ₀ + _z - These values are known per se

· - "'■ _d j, arithmetic units entered, these being the length of the

b - h ₀ + ^, [Τ "'" · Distance of the deceleration path for the instantaneous

35 continuously determine borrowed speed. Comes

^{! a} Dj _{c time} steps / based on the change - now a command from a breakpoint, e.g. B. from a speed of the'mechanischen variables, floors can be chosen to be extremely small, so the available up to then will be extremely small. This approximates the existing path length S very well with that of the integral through the arithmetic unit erd. Since the accuracy of the mean length of the deceleration path s assigned to the speed of the instantaneous digital travel arithmetic units can be increased at will by increasing the number of digits 40, the position depends on the situation. If S ^ s, the command is executed. : ·· ■ nier accuracy of a drive with digital setpoint actual 5 <s, then the execution of the command is not '"' ^! Value specification and position control only possible with the resolution.

The travel curves in F1 ^ 3 to 5 apply to the

'' can be driven, and the dynamic characteristic 45 case that the machine is at its maximum speed

: '^!; Shafts of the control loop from ⁿ ' ^{cnt reached nal}

^{11 !!} ·: "'' Digit integrators show, in addition to the essentials, in the output of the integrator 44 U ₂ ) appears the

■ ' ^l advantage. To be able to save results as long as you like. Speed t- (i) in the form of the driving curves.

still have the advantage. that the travel distance is equal to the time integral of the representable variable can be integrated through each pulse. Beispiels- 50 speed and therefore corresponds to the area under way digits integrators can be used to calculate the curve. V (t) This is according to FIG 5 is to use the areas or volumes, if a trapezoidal surface BEHL et al sections AB, C and Lange or integrated over a diameter. DEF as well as GHJ and 1 KLM are each the same. The paths can easily be represented by impulses. Trapezoid can represent a parallelogram BEHO with the. This becomes the subject of the present 55 baseline
Invention advantageously exploited. b + b
For a more detailed explanation, reference is made to F 1 g. 2 to 5 ~ ^ TiT

referenced. 2 j

2 shows the course of the travel curve when di is reached

the maximum speed. ^ ⁰

In Fig. 3 is the diagram r = f (t) for driving _{the baseline}

applied course. The acceleration when starting and em urci ^ v

ren in the time ί ,, is here in terms of amount higher than

the deceleration when braking in the time i _r / h, \

In the diagram, the areas 1. 2. 3 and 4 65 ii ^ _h J

the desired braking distance according to the expression s = / rd t

The determination of these represent the braking distance _{- wpr} H _Pn

This is how it happens. that the surfaces 2 and 4 are broken down.

The common height is fr, · f ,. The total area is with it

F _n = λ = ί,

ft. dft df With dft

= Absolute value of the change in acceleration,

ft, = absolute value of the acceleration, b ₂ = absolute value of the deceleration.

This expression can be represented by the trapezoid APRN of the same area with the width f, consisting of a rectangle APSN with the height .

The digit integrator 40 is set to the initial value V ₁₁ ,, at the beginning of a journey at time / = 0 and gives the sum at the output

Vu = v "" + ft,

ίο off.

The trapezoidal area and thus the sum of the distance covered and the braking distance that results if at this moment the acceleration is started to decrease, you get at the exit of the following digit integrator 36 according to the equation

Shalt = '' «· '■

di

and a triangle PRS, its height

K)

Both height measures have the dimension of a speed. Worth the start

ft, + ft ₂

2 ™ di

at time t = 0, V becomes the constant factor _{with Ho}

marked with bH .

The height of the triangle is

I ₊ *

The calculation applies to any point between C and D of the general travel curve in FIG. 2. If the maximum speed of the drive is reached over longer distances, the increase in distance proportional to the speed must be added to the result of the previous calculation at the acceleration value zero, i.e. when driving at constant speed. In Fig. 2 this is the area under the curve section FG.

The position control loop forms the setpoint / actual value difference s digital. The nominal path value arises in the digit integrator 46 of FIG. 1. The actual value is with determined by an incremental measuring process. A pulse generator with direction of rotation information is included the drive motor 16 is coupled. An up-down counter sums the output pulses with the correct sign. Instead of the incremental measuring method a coded system, for example with an angle encoder, can be used.

The numerical value of the path control deviation Δ s is, as shown in FIG. 1 can be seen, transformed into an analogous size and as an additional size in the subordinate

• Speed control loop introduced. The speed setpoint is taken from the digit integrator and also converted into an analog voltage. The speedometer machine 18 supplies the actual speed value.

The target position is advantageously entered via the push-button panel 32. This facility läßl also through other digital devices, e.g. B. Replace tape reader. The digit integration system to the default the setpoints and the calculation of the braking distance can be infinitely variable with any type of Drive work together.

For this purpose 4 sheets of drawings

Claims (2)

Ί> zesten is, so that from the finally rolled out patent claims: Rolling stock to be separated part of this route including a short one, from the reel behind the 1. Device for determining and regulating the rolling stand that corresponds to the part of the rolling stock. Velocity of a moving object 5. There has been no lack of efforts Genauigzum purpose of positioning k using _e it to increase the control of these drives, but a digital computer with Digkal analog-To _T is either or objection Lung for the adjustment of the Controlled variable a with numerical target control required time too long, or the achievable specification, whereby the speed setpoint of the accuracy corresponds to the optimal needs, moving object corresponds to a driving curve , in particular that of the change in acceleration (jerk), the acceleration distance of the path covered by this, is supply and speed adheres to, and where in conveyor systems, especially elevators. If the possible stopping point corresponds to this, the requirement must be met that, for example, with the target point the delay is initiated 15 the elevator car disappears with only one, characterized in that the slight inaccuracy occurs at the point of stopping possible stopping point of the moving object at which the floor of the car with is constantly and independently of the calculation of the floor of the approached floor in the travel curve determined (36, 40) and a path of the same height. For this purpose, the control system usually ensures that the drive (16) follows the target course of the distance covered by the travel curve on which the calculation of the stop, cabin, initiators or control devices to the point is based. Initiation of the braking process applied. 2. Device according to claim 1, characterized J overall _n this context, it has become known, indicates that the calculation of the possible braking process as a function of the speed holding point of the moving object with 25 speed of the cabin. But there are others two integrators (36, 40) happens. Parameters such as acceleration, driving with the maximum speed z. B. not taken into account, so that further auxiliary devices are required with which when reaching the selected floor 30 works by means of a slow speed adjustment of the height of the floor area of the cabin compared to the Floor space of the approached floor is required. In the known method for regulating the There are already methods for regulating the drive 35 but not the drive of elevator systems of a moving object, in particular the optimal speed and accuracy that which is covered by this object aims which one is desired. Way, became known. With conveyor systems, the speed depends on the So it has become known that the employment, ie the adjustment of the rolls of the roll stand from rolling 4 ° to drive through a predetermined distance can be achieved, among other things, from the works, in a certain way, for. B. in the acceleration, the load and the delay of the execution of a program. Here drive off. For each route, however, there is the difficulty of the exact, but also a different driving speed, if you achieve a timely quick adjustment or readjustment of the optimal utilization of the system the roll stand on. The achievement of the tax technology · cannot be achieved. The so far of the exact contact point is usually a grain applied mv known drive controls between speed and accuracy of the let de * ¹ -nib - · ~ ne limited number of maximum positions. In this process of hiring or speed ^. *.-...;,. B. 2 to 3, too. Each of these of the readjustment of the rollers is the start-up process 5 ° speed, serves a certain travel range, the roller adjustment motors and the braking of these . B. have been through a display device, a certain speed is used. Have achieved this given position. This process speed has to be set after the smallest occurrence but cannot be set with the conventional means with 55 mending floor level. If this is the best possible speed and accuracy z. B. the seldom used cellar, the funding is to be achieved. Either there is an overshooting of the performance in the higher upper floors, which is a much desired job with a slow downsizing. leading return to, or the roller setting- So there is a need to promote the same- Before reaching the desired position ^6o valid whether long or short distances are to be driven through at creep speed. are, generally at an optimal speed Similar relationships occur when the drive is carried out. This affects the accelerating reels on, of which, for example, rolling stock, movement and the delay as well as the transition z. B. sheet metal, during the machining process on- between the two. and is processed. In this case, the ⁶ 5 With the previously common and known Förderan-Difficulty, the reel was exactly in the position, the braking distances are stopped by switching rulers at the, in which the distance of the rolling material conveyor path or at a copier, between the reel and the roll stand on the kür- When the speed changes or