Sensor signal converter for machine tools and production machines, and also robots

Abstract

The invention relates to a sensor signal converter for machine tools and production machines, and also robots, which generates pulsed signals from sensor values transmitted via a drive bus. The sensor signals (GU1, GU2) can be transmitted on the drive bus (AB1-AB4) in real time, can be converted into sensor-compatible pulsed signals by a sensor signal converter (GU1, GU2) in real time and can be sent to other appliances, optionally in real time. The data link (AB1-AB4) having real-time capability which can be used is an Ethernet having real-time capability.

Description

FIELD OF THE INVENTION

The invention relates to a sensor signal converter for machine tools and production machines, and, robots, hereinafter machines which generate pulsed signals from sensor values transmitted via a drive bus.

BACKGROUND OF THE INVENTION

SIMOVERT MASTERDRIVES SLE/SLE-DP-SIMOLINK-Encoder, GWE-477 763 4070.76J, Siemens AG 2001 discloses an encoder which simulates sensor values on an electrical shaft and provides a central actual machine value (actual position value) which is generated from a reference nominal value. The SIMOLINK encoder generates two pulsed signals shifted through 90° and a zero pulse from a nominal angle value transported by means of SIMOLINK (optical waveguide connection). These are made available to other appliances by the encoder via RS422. The encoder thus simulates a pulse sensor with selectable, programmable quantization intervals.

SUMMARY OF INVENTION

It is an object of the present invention to provide a sensor signal converter which can respectively receive, convert and forward sensor signals in real time. The present invention achieves this object as a result of 1) sensor signals being able to be transmitted on a drive bus in real time; 2) the signals being able to be converted into sensor-compatible pulsed signals by a sensor signal converter in real time; and 3) the signals being able to be sent to other appliances in real time. The novel design of the sensor signal converter enables appliances which are not compatible with the main drive bus, for example drives from different manufacturers, to be coupled on a drive technology basis by means of a sensor interface.

A preferred embodiment of the present invention is characterized in that a control computer generates synthetic nominal values for at least one signal sensor converter and/or at least one drive regulator. Thus, various process information and/or process stipulations can be used in a control computer to generate synthetic nominal values. These values can be changed according to program execution and/or process flow.

In another preferred embodiment of the invention, a control computer receives nominal values from at least one further automation component. Thus, nominal values can advantageously be sent from automation components to a sensor converter using a control computer, for example, a drive bus. In this context, the control computer can serve as conversion component if the automation component prescribing nominal values cannot be compatibly connected to the sensor converter. Similarly, nominal value corrections or alterations can be made in the control computer.

In yet another preferred embodiment of the invention, a real and a synthetic nominal value source is flexibly assigned to at least one sensor signal converter using a control computer and/or a drive regulator. Hence, nominal value sources can be arbitrarily assigned to sensor converters in the configuration phase of a technical installation.

In still another preferred embodiment of the invention, a real and a synthetic nominal value source is flexibly assigned during operation on the basis of a mode of operation and/or execution of a program and/or an instance of fault. In this way, nominal value sources can be flexibly assigned to sensor converters according to demand and requirement even during operation of a technical installation.

Preferably, a clock signal can be produced or derived in the sensor signal converter in synchronism with the communication clock of the input data link having real-time capability. Thus, clock generation or formation in the sensor signal converter takes place strictly in synchronism with the transmission clock.

It is preferred that the sensor signal converter is an integral part of a drive regulator. This means that integral system resources of the drive regulator can advantageously be used. This minimizes the hardware costs and the complexity of installation for appliances or drives. Further, at least one real-time data link which can be used for the drive regulator is an Ethernet which makes it possible to use a standardized bus protocol which can be used universally and permits a high transmission capacity. Short bus cycles allow data to be transmitted in the system with real-time capability, which permits nominal value discrepancies to be quickly corrected.

DRAWINGS

An exemplary embodiment of the invention is shown in the drawing and is explained in more detail below. In the drawing:

FIG. 1 shows an association of drives with a data link, having real-time capability, and sensor signal converters.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an association of drives which has data links AB 1 to AB 4 having real-time capability. In this case, a drive comprises at least one electrically driven motor M 1 to M 5 , a converter containing power electronics LE 1 to LE 5 , and a drive regulator AR 1 to AR 5 . As shown in FIG. 1 , the power electronics LE 1 to LE 5 are marked by a rectangle with an IGBT symbol (Insulated Gate Bipolar Transistor). A drive regulator AR 1 to AR 5 can have further data links which connect it, by way of example, to a control computer L or sensors G 1 , G 2 . The drive regulators AR 1 to AR 4 have a drive bus AB 1 to AB 4 having real-time capability which is in the form of a ring.

In the illustration in FIG. 1 , there are also sensor signal converters GU 1 , GU 2 on the drive regulators AR 3 and AR 4 . In this case, the sensor signal converters GU 1 , GU 2 may be an integral part of the drive regulators AR 1 to AR 5 or may be arranged externally thereto.

In the illustration in FIG. 1 , the drive regulator AR 5 is not equipped with a drive bus AB 1 to AB 4 having real-time capability. To couple this drive to the drives having the drive regulators AR 1 to AR 4 , a sensor signal converter GU 2 is arranged on the drive regulator AR 4 , said sensor signal converter receiving sensor signals from the sensors G 1 , G 2 in real time, and depending on configuration, sending a sensor value to the drive regulator AR 5 . The drive bus AB 1 to AB 4 having real-time capability means that it does not matter which drive regulator AR 1 to AR 4 has the sensor G 1 , G 2 whose information is to be sent to the drive regulator AR 5 . The sensor G 1 is mechanically coupled to the motor M 1 , which is shown in the illustration shown in FIG. 1 by two lines connecting the sensor G 1 to the motor M 1 .

By way of example, the drives having the drive regulators AR 1 to AR 4 may be arranged in a production machine in which the motor M 1 releases a product of the machine. A sensor G 1 detects the position of the motor M 1 and sends this signal to the drive regulator AR 1 . This drive regulator sends the information via the drive bus AB 1 to AB 4 having real-time capability to the drive regulator AR 4 . There, the actual position value of the motor M 1 is converted into sensor-compatible pulsed signals in the sensor signal converter GU 2 . These signals are transmitted to the drive regulator AR 5 controlling the motor M 5 . By way of example, this motor may operate a conveyor belt which is coordinated with the production machine and is used to transport the finished product away.

When production installations are re-equipped, drives from different manufacturers may need to be connected to one another. However, these do not always have bus interfaces which can be used to communicate using compatible bus protocols. In this case, it is possible to produce an item of drive information, for drives which are to be coupled, using a sensor G 1 , G 2 which is to be installed, since drive regulators AR 1 to AR 5 usually have sensor interfaces. In addition, the procedure described may represent an inexpensive alternative when it is not possible to equip a drive with a data link AB 1 to AB 4 having real-time capability for cost reasons.

The measured signals from the sensors G 1 , G 2 can be flexibly assigned to the sensor converters GU 1 , GU 2 via the drive bus AB 1 to AB 4 in the system. By way of example, this can be done using the control computer L, which is able to collect, evaluate and possibly display superordinate process data. It is also conceivable for the control computer L to be able to be used to configure the installation.

Finally, it should be mentioned that the use of an Ethernet having real-time capability permits the use of a standardized bus protocol which can be used universally. The Ethernet provides a high transmission capacity and represents an inexpensive alternative to existing drive bus systems.

Claims

1. A sensor signal converter system for machines which generate pulsed signals from sensor values comprising at least one sensor signal converter and at least one bus drive for transmitting sensor signals in real time, wherein the sensor signals are converted into sensor-compatible pulsed signals by the at least one sensor signal converter in real time, and further wherein converted signals can be sent to at least one appliance in real time.

2. The sensor signal converter system according to claim 1, further comprising a control computer for generating synthetic nominal values for the at least one sensor signal converter, and/or at least one drive regulator.

3. The sensor signal converter system according to claim 2, wherein the control computer can be sent nominal values from at least one further automation component.

4. The sensor signal converter system according to claim 3, wherein a real and a synthetic nominal value source can be flexibly assigned to at least one sensor signal converter using a control computer and/or a drive regulator.

5. The sensor signal converter system according to claim 4 wherein a real and a synthetic nominal value source can be flexibly assigned during operation of the machine.

6. The sensor signal converter system according to claim 1, further comprising a clock signal in the sensor signal converter, and a communication clock in the bus drive, and wherein said clock signal is synchronized with said communication clock.

7. The sensor signal converter system according to claim 1, wherein the sensor signal converter is an integral part of a drive regulator.

8. The sensor signal converter system according to claim 1, wherein at least one real-time bus drive which can be used for the drive regulator is an Ethernet having real-time capability.