EP0504867A1 - Computer controlled system for lifting loads with at least two hoists - Google Patents

Abstract

In a computer-controlled system for lifting loads, particularly for stages and multi-purpose halls comprising - at least two independently controllable hoists (4a, 4b), - a control computer (1) for individually monitoring the system and controlling the individual hoists, which carries out an actual/nominal value comparison, - an operating terminal (5), - an operating computer (6) for administering the operating terminal (5) and transmitting travel commands to the control computer (1), - a network (2) for connecting control computer (1), operating computer (6), operating terminal (5) and the individual hoists (4a, 4b), it is provided according to the invention that - the network (2) is a ring network and that - the control computer (1) has a multi-channel structure with at least two channels (1a, 1b) and independently carries out the actual/nominal value comparison in each channel (1a, 1b) as well as alternately a monitoring of each channel (1a, 1b) by the other one (1b, 1a) and, when safety-relevant deviations are detected, stops the system for lifting loads via switch-off lines, which are designed to have at least two channels, the actual/nominal value comparison including at least a detection of the position and of the state of movement of the individual systems for lifting loads (4a, 4b, ...), a weight sensing, a monitoring for slack chains and a monitoring for the synchronous running of hoists (4a, 4b, ...) connected in a group. <IMAGE>

Description

The invention relates to a computer-controlled hoist system with at least two hoists, which is particularly suitable for stages and multi-purpose halls. Such hoist systems are mainly used in studios, stages, discotheques, in shows and other events.

Lifting hoists are to be understood as supporting means that can move loads. Hoists consist of a drive and the associated supporting structure, e.g. Chain hoists and wire rope hoists. The hoist system is intended, for example, to raise an "artificial" lace-up floor, described below, and the PA and lighting systems attached to it. The "artificial" lace-up method is made possible by the fact that several hoists are grouped together.

A secure locking of the system must be ensured, since the "artificial" lacing floor (weighing several tons) can be above an audience.

From DE-A-32 33 468 a control for a lace-up machinery is known in which each drive is assigned an autonomous computer. All drive computers are connected to a common bus together with a common switching computer. An operating computer is assigned to an operating terminal and is connected to the switching computer. Position data of their respective drive are fed to the drive computers via actual value transmitters; depending on commands from the switching computer, they control and monitor their drive, including the calculation and regulation of speeds, and provide position data and error messages to the switching computer. The operating computer monitors and manages command buttons, switches and displays on the operator terminal, interprets group combinations of drives, stores data chains for specified movement sequences and transmits travel commands to the switching computer. The switching computer monitors the data traffic from and to the operator computer, as well as from and to the drives or drive computers, it keeps lists with actual values of all drives and permanent error states, continuously checks the data paths to all other computers and carries out the necessary switching measures in the event of an error. The drive computers continuously calculate the target position of your drive by evaluating direction, speed and group composition commands and initiate the necessary corrections in the event of deviations between the actual and target positions.

The drives are switched off when deviations between the actual and target positions are found that exceed a specified maximum value.

The drive computer carries out a safety check for the drives and itself, in particular tracking error and slack rope monitoring, as well as monitoring of pre-and emergency limit switches.

The switching computer is connected to the operating computer via a serial interface and a serial reserve interface, as well as associated lines, and it automatically switches over to the reserve interface in the event of data traffic disruptions.

The position data of the actual value transmitters are fed to the switching computer. When grouping drives, it checks the synchronism of the drives within the groups independently of the drive computers of the groups by comparing the position data.

The control panel has one or more master switches that enable the group travel speed and direction to be set for group combinations of drives via the operating computer.

This known control system has a number of safety-related disadvantages. So it does not comply with the regulations of the accident prevention regulation for stages and studios (VGB 70) of the administrative and professional associations. In addition, these controls do not meet the safety requirements according to DIN V 19250 01/89 and VDE 0801 10/90 Basic safety considerations for MSR protective devices.

Weight detection is not carried out in the prior art, which represents a security risk. If a weight is attached to the drives which is greater than the maximum permissible load at the suspension point of the respective drive, there is a risk of the roof structure collapsing. A shift in weight within a group, for example due to slipping of the attached construction or due to the failure of a hoist, can also lead to an impermissible load on the roof structure. If, for example, a truss construction is brought to the desired height by several drives at the same time, this also involves dangers.

Under truss constructions are e.g. Understand wood, steel or aluminum truss constructions. By combining several trusses, an "artificial" lace is formed. On this "artificial" lacing floor e.g. Lighting and sound systems attached. If the weight of the attached load is too high, the truss construction can break, or there is a risk that the maximum load on the suspension points will be exceeded. Since there are no weight recording devices at event venues, an estimate of the loads to be suspended in the roof structure is necessary, which is not a reproducible method on the one hand and leads to errors on the other.

Furthermore, the usual computers are single-channel. A single-channel switching computer runs the risk that system errors that occur will not be recognized because there is no comparison of the process data. The switching computer is equipped with the operating computer through a two-channel data line, but if the operating computer fails, the control panel can no longer be used. If the operating computer fails, no load could then be moved out of the danger area. This danger is further increased by the possibility of operating errors due to a very large number of control buttons - according to DE-A-32 33 468, about 300 buttons, 250 light-emitting diodes and 100 digit display decades are necessary.

The invention has for its object to provide a computer-controlled hoist system of the type mentioned, which meets the above-mentioned safety requirements and in particular avoids overloading the roof structure, the truss structure or individual hoists. This is to avoid endangering personnel, artists and the public. Furthermore, such a hoist system to relieve the personnel should be easy and clear to operate.

• wenigstens zwei unabhängig steuerbaren Hubzügen,
• einem Steuerrechner zur Überwachung des Systems und Steuerung der einzelnen Hubzüge, der einen Ist/Sollwert-Vergleich durchführt,
• einem Bedienterminal,
• einem Bedienrechner zur Verwaltung des Bedienterminals und Übermittlung von Fahrbefehlen an den Steuerrechner,
• einem Ringnetz zur Verbindung von Steuerrechner, Bedienrechner, Bedienterminal und der einzelnen Hubzüge, wobei
  das Netz ein Ringnetz ist und
  der Steuerrechner eine Mehrkanalstruktur mit wenigstens zwei Kanälen besitzt, der in jedem Kanal unabhängig den Ist/Sollwert-Vergleich vornimmt sowie wechselseitig eine Überwachung jedes Kanals durch die jeweils anderen und bei Feststellung von Abweichungen das Hubzugsystem über wenigstens zweikanalig ausgeführte Abschaltleitungen stillegt, wobei im Rahmen des Ist/Sollwert-Vergleichs wenigstens eine Erfassung der Position und des Bewegungszustandes der einzelnen Hubzüge, eine Gewichtserfassung, eine Schlaffkettenüberwachung und eine Gleichlaufüberwachung von in Gruppe geschalteten Hubzügen vorgenommen wird,

gelöst.This task is accomplished with a computer controlled hoist system

• at least two independently controllable hoists,
• a control computer for monitoring the system and controlling the individual hoists, which carries out an actual / setpoint comparison,
• an operator terminal,
• an operating computer for administration of the operating terminal and transmission of driving commands to the control computer,
• a ring network for connecting the control computer, control computer, control terminal and the individual hoists, whereby
  the network is a ring network and
  the control computer has a multi-channel structure with at least two channels, which independently performs the actual / setpoint value comparison in each channel and mutually monitors each channel by means of the other and, if deviations are determined, shuts down the hoist system via at least two-channel shutdown lines, whereby within the actual / target value comparison at least detects the position and the state of movement of the individual hoists, weight detection, slack chain monitoring and synchronism monitoring of hoists connected in a group,

solved.

The hoist system according to the invention is based on a multi-channel, in particular two-channel control computer, that is to say a control computer with two or more programmable logic controllers ("PLC"), which is connected to the hoist trains, the operating terminal and the operating computer via a coaxial ring network. With a two-channel structure, the control system is designed redundantly; Further control of the system is guaranteed even if one channel fails. At the same time, one channel is monitored by the other. If deviations between the channels are found that exceed a specified tolerance range, the system is shut down or other specified measures are initiated. The mutual monitoring of the two channels takes into account any time shifts that occur in the parallel arithmetic operations by specifying a time interval within which there must be agreement.

The operator computer is assigned to the operator terminal, but the operator terminal can be used independently of the operator computer. This is particularly necessary when individual hoists still have to be operated. In the case of group connections of the drives, however, the use of the operating computer is preferable. Accordingly, the hoist system according to the invention allows both individual trips and group switching of the respective drives.

The control computer is informed of the respective position of the drives via actual value transmitters, and likewise, preferably via strain gauges known per se, the respective load of the individual hoist trains. All the hoists in motion in a group are checked for synchronism, load and height position, all motors that are at a standstill are checked for standstill and load. When the individual trains move, the height position and load are checked.

At the same time, the control computer preferably maintains lists with the maximum permissible loads of the suspension points, the exceeding of which stops the entire system and, if necessary, predetermined, safety-related measures are carried out, for example relieving the suspension points by returning to a starting position. Error messages are forwarded to the operator computer and displayed on it.

The control computer also continuously checks the data traffic in the coaxial ring network and, in the event of malfunctions, carries out the specified, safety-related measures, such as decommissioning the hoist trains or returning to a specified or starting position.

The control computer monitors and manages the command buttons, switches and displays of the operator terminal, interprets group combinations of the individual hoists and stores data chains for specified movement sequences. The control computer releases the travel commands when it has checked all the processes.

The hoist system has a permanently installed height measuring system which is used to compare the actual / setpoint of the Tax calculator is involved. During group journeys, the individual hoists are monitored for compliance with the permissible height deviation within the group in order not to destroy suspended truss constructions and to avoid weight shifts within a group of hoists and the resulting overloading.

A weight detection by means of load measuring devices preferably arranged on the individual drives makes it possible to recognize load shifts within a group and to stop the drives when the permissible tolerance is exceeded and, if necessary, to take further measures.

If the minimum load of an individual hoist or a group of hoists is undershot, which can occur, for example, when a crossbar or the bottle of a hoist is placed on an obstacle, the system is also switched off to prevent the danger of slack rope or slack chain formation.

A slack chain shutdown must be carried out when the hoist is not under load so that dangers to people are avoided. If an unloaded hoist hits an obstacle, the hook block stops at this point and the chain continues to descend (slack chain formation).

If this condition goes unnoticed, the hook block can fall to the ground and injure a person if it falls. A slack chain shutdown on loaded hoists that are moved in a group can avoid the following problems. If the group consists of, for example, four drives and when hitting an obstacle if three hoists are relieved, there is a risk of overloading the fourth hoist. A punctiform load arises which contains a risk of overloading the drive, the traction means (breakage of the chain or the rope) or the permissible ceiling load at this suspension point can be exceeded. The same point overload can occur if three hoists of the group described above fail at the same time.

All safety-relevant data is stored independent of the network, preferably in a battery-buffered RAM of the control computer. Preferably, all the data that has occurred during operation, in particular the minimum or maximum loads that have occurred, is also stored within the control computer in order to obtain and be able to retrieve and reproduce a reproducible event log and to document operating errors that occur.

The drive is monitored for synchronism by the installed height measuring device, for example using an incremental encoder. However, it is also conceivable to define a so-called calculated routing. The control computer calculates the data for the lead train and then compares it with the real measured data. In addition to comparing the values through the two channels of the control computer, further measures to increase security are possible. A preferred option is to record the position and weight multiple times. Both channels of the control computer compare the measured values with each other and initiate the safety-related measures in the event of deviations. If the position and the weight of at least some of the hoists are recorded twice, each is expediently of the two parallel data records from one channel each.

Depending on the application, group formation rules can be defined, e.g. prevent loaded drives from being deleted from a group before they have been relieved, and to prevent double assignment in two different groups.

The control enables opposite movements, and if different distances are specified, the control computer calculates the necessary speed of all trains so that all trains arrive at their destination at the same time. Time-shifted movements, movements in the form of waves, rocking movements and movements in tilting sequences are also possible.

To prevent unauthorized use, a logon procedure can be installed on the operating computer, which must first be carried out before the system releases the system.

All data that is saved, be it security-related or event-related data, can be saved on disk as well as on disk. This data can also be printed out using a log printer.

The operating computer can be divided into further sub-control panels, which can then be brought into areas in which complicated movements are carried out. Only drives that were previously approved by the operator computer can be selected on the sub-control panels. The operating computer coordinates the various sub-control panels and gives them Data from all sub-control panels to the control computer. However, a version is also possible in which all control panels communicate directly with the control computer.

The hoists can either be installed stationary or movable.

The control can also be used for all other drive types, e.g. hydraulic drives that lift platforms and platforms.

Fig. 1

schematisch die Verknüpfung der einzelnen Komponenten des Hubzugsystems,

Fig. 2

schematisch die Verknüpfung zweikanaliger Steuerrechner mit den einzelnen Antrieben,

Fig. 3

schematisch die Verknüpfung zweikanaliger Steuerrechner mit dem Bedienterminal,

Fig. 4

schematisch die Verknüpfung Bedienrechner mit dem zweikanaligen Steuerrechner,

Fig. 5

schematisch das koaxiale Ringnetz,

Fig. 6

ein Trackingsystem auf der Basis eines erfindungsgemäßen Hubzugsystems.

Preferred embodiments of the invention are described below with reference to the drawings. Show it:

Fig. 1

schematically the connection of the individual components of the hoist system,

Fig. 2

schematically the connection of two-channel control computers with the individual drives,

Fig. 3

schematically the connection of two-channel control computers with the operator terminal,

Fig. 4

schematically the link between the operating computer and the two-channel control computer,

Fig. 5

schematically the coaxial ring network,

Fig. 6

a tracking system based on a hoist system according to the invention.

1 shows the assignment of the individual components to one another. The two-channel control computer (1) has access to the operator terminal via the coaxial ring network (2) (5), the operating computer (6) and the individual drives (4a, 4b, 4c, 4d, ... 4n).

Fig. 2 shows the two-channel structure of the control computer, in which each of the channels (1 and 2) has independent access to the data and to the ring network. All data from the drives to the control computer are read from both channels of the control computer and a comparison between the channels takes place. This measure above all prevents multiple errors and prevents misinformation from interfering with the operational process. If the comparison leads to different values, the system is shut down or other, predetermined measures are initiated.

The clock of the system is specified by a defined time window, which also regulates the timing of the channels. The weight is recorded, for example, via strain gauges (DMS), which transmit the recorded values to the channels of the control computer via load-frequency converters (LSW) and frequency-voltage converters (FSW). In the event of an overload, the relevant contactors and the other motors are switched off via the main contactors.

Likewise, the data from the operator terminal according to FIG. 3 and from the operator computer according to FIG. 4 are checked by both channels of the control computer.

5 shows the coaxial ring network with a main loop and a sub loop. For example, If the main loop to the channel (1) fails, the sub loop is immediately switched to.

A possible application example is the positioning of lighting and sound systems above the Stage at music events. First, the "artificial" lace-up floor is moved to the working height with the hoists. Then music boxes are moved onto the stage, which can now be attached to any point on the "artificial" lacing floor, if the maximum permissible load in the suspension points is not exceeded.

Another application of the hoist control is the "tracking system" described below, which has hoists that move a frame in the vertical direction. At the same time, this tracking system, e.g. B. on a rail system, movable in the horizontal direction.

The overall system can be implemented as shown in FIG. 6.

With the hoists 4a, 4b, 4c, a traverse structure 10 is moved in height. A rail system 11, on which a frame 12 is moved, is mounted on the truss construction 10. There are drives on the frame 12 which can move or tilt a second frame 13. A drive is also provided for the horizontal movement of the frame 12.

All of these drives can be moved using the control described at the beginning. Single and group trips are possible. The driving levers are located on the central control panel or a secondary panel, which enables all functions of the tracking system. The driving levers increase the speed proportionally to the lever design. This means that the speed is infinitely adjustable. The maximum speed of the individual drives is preferably limited by the control. With the help of the drive levers movement sequences can be followed in the teach-in process and saved afterwards. Individual movement sequences, also called "cue's", can then be linked to form more complex movement sequences. Movements assembled in this way can then be called up again automatically.

The driving data can also be entered using the keyboard.

Several monitors can be mounted on the control panel. A variant is, for example, that the current driving data, the start and end positions are displayed on a monitor of the control panel. A floor plan of the local conditions is shown on a second monitor and the movements of the drives are shown to scale. It can be conveniently switched between different views (side view, top view, etc.).

Predefined safety areas can prevent hazardous areas from being approached.

The user interface on the monitor naturally offers further display options, which are not listed here.

Another special feature that the tracking system contains in particular is the possibility of moving a scanner head of a laser system via the movable frame. A fiber optic cable makes it possible for the scanner head of the laser to move in space, thereby producing laser effects in three-dimensional space. A combination of the tracking system with the laser opens up new, varied show and lighting effects in an unprecedented way.

Claims (18)

Computer-controlled hoist system, especially for stages and multi-purpose halls with - at least two independently controllable hoists (4a, 4b), - A control computer (1) for monitoring the system and controlling the individual hoists (4a, 4b), which carries out an actual / setpoint comparison, - an operating terminal (5), - an operating computer (6) for managing the operating terminal (5) and transmitting travel commands to the control computer (1), - a ring network (2) for connecting the control computer (1), the operating computer (6), the operating terminal (5) and the individual lifting trains (4a, 4b), characterized in that - The network (2) is a ring network, and - The control computer (1) has a multi-channel structure with at least two channels (1a, 1b) and independently carries out the actual / setpoint comparison in each channel (1a, 1b) and mutually monitors each channel (1a, 1b) by the other (1b, 1a) and when determining safety-related deviations, the hoist system over at least Two-channel shutdown lines are shut down, whereby within the scope of the actual / setpoint comparison at least one detection of the position and the movement status of the individual hoist trains (4a, 4b, ...), weight detection, slack chain monitoring and synchronism monitoring of hoist trains connected in group (4a , 4b, ...) is provided. Hoist system according to claim 1, characterized in that the control computer (1) has a two-channel structure and the ring network (2) consists of a main loop and a sub loop. Hoist system according to one of claims 1 or 2, characterized in that a determination of the total weight and the respective weight coming to the individual hoists (4a, 4b, ...) is provided, preferably via stretch marks. Hoist system according to Claim 3, characterized in that the weight of hoist trains (4a, 4b, ...) connected in a group is additionally recorded. Hoist system according to one of claims 1 to 4, characterized in that the actual / setpoint comparison is carried out using a process image stored in the control computer (1). Hoist system according to claim 5, characterized in that the process image has a tolerance range, the shortfall or overshoot of which causes the hoist system to be shut down. Hoist system according to one of claims 1 to 6, characterized in that the actual / target value comparison of the weight detection is carried out on the basis of predetermined maximum loads of the supporting structure and the individual hoists (4a, 4b, ...) stored in the control computer (1). Hoist system according to claim 7, characterized by multiple detection of the weight and the position of at least some of the hoists (4a, 4b, ...). Hoist system according to claim 8, characterized by a comparison of the recorded weight and position data by the channels (1a, 1b) of the control computer (1). Hoist system according to one of claims 7 to 9, characterized in that the control computer (1) keeps lists of the maximum permissible loads of the suspension points and initiates safety-related measures when these permissible loads are exceeded. Hoist system according to one of claims 1 to 10, characterized by a network-independent storage of all security-related data. Hoist system according to one of claims 1 to 11, characterized by a retrievable storage of the operating sequence within the control computer (1). Hoist system according to one of claims 1 to 12, characterized in that the operating terminal (5) can be operated independently of the operating computer (6). Hoist system according to one of claims 1 to 13, characterized in that for synchronism monitoring of the hoists (4a, 4b, ...) incremental encoders are provided. Lifting train system according to one of claims 1 to 14, characterized in that a guide train is defined for synchronous monitoring of the lifting trains (4a, 4b, ...). Hoist system according to one of claims 1 to 15, characterized in that a plurality of operating terminals (5) are provided, each of which controls individual or groups of hoists (4a, 4b, ...). Hoist system according to one of claims 1 to 16, characterized in that it can be moved in the horizontal and vertical directions. Hoist system according to claim 17, characterized by a height-adjustable truss construction with a rail system and at least one frame which can be moved vertically and horizontally on the rail system.

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