Machine tools 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.
Machine tools claims
I claim:
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.
Machine tools 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.degree. 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 AB1
to AB4 having real-time capability. In this case, a drive comprises
at least one electrically driven motor M1 to M5 a converter containing
power electronics LE1 to LE5 and a drive regulator AR1 to AR5.
As shown in FIG. 1 the power electronics LE1 to LE5 are marked
by a rectangle with an IGBT symbol (Insulated Gate Bipolar Transistor).
A drive regulator AR1 to AR5 can have further data links which connect
it, by way of example, to a control computer L or sensors G1 G2.
The drive regulators AR1 to AR4 have a drive bus AB1 to AB4 having
real-time capability which is in the form of a ring.
In the illustration in FIG. 1 there are also sensor signal converters
GU1 GU2 on the drive regulators AR3 and AR4. In this case, the
sensor signal converters GU1 GU2 may be an integral part of the
drive regulators AR1 to AR5 or may be arranged externally thereto.
In the illustration in FIG. 1 the drive regulator AR5 is not equipped
with a drive bus AB1 to AB4 having real-time capability. To couple
this drive to the drives having the drive regulators AR1 to AR4
a sensor signal converter GU2 is arranged on the drive regulator
AR4 said sensor signal converter receiving sensor signals from
the sensors G1 G2 in real time, and depending on configuration,
sending a sensor value to the drive regulator AR5. The drive bus
AB1 to AB4 having real-time capability means that it does not matter
which drive regulator AR1 to AR4 has the sensor G1 G2 whose information
is to be sent to the drive regulator AR5. The sensor G1 is mechanically
coupled to the motor M1 which is shown in the illustration shown
in FIG. 1 by two lines connecting the sensor G1 to the motor M1.
By way of example, the drives having the drive regulators AR1 to
AR4 may be arranged in a production machine in which the motor M1
releases a product of the machine. A sensor G1 detects the position
of the motor M1 and sends this signal to the drive regulator AR1.
This drive regulator sends the information via the drive bus AB1
to AB4 having real-time capability to the drive regulator AR4. There,
the actual position value of the motor M1 is converted into sensor-compatible
pulsed signals in the sensor signal converter GU2. These signals
are transmitted to the drive regulator AR5 controlling the motor
M5. 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 G1 G2 which is to be installed, since drive
regulators AR1 to AR5 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 AB1 to
AB4 having real-time capability for cost reasons.
The measured signals from the sensors G1 G2 can be flexibly assigned
to the sensor converters GU1 GU2 via the drive bus AB1 to AB4 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.
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