Machine tools abstract
A device for automating and/or controlling machine tools or production
machines is described. The device includes at least one computer
which is located remote from a machine. The computer operates like
a handheld controller and is connected via at least one bus system,
which can be wired or wireless, with each machine for unidirectionally
or bidirectionally transmitting data and control signals. All control
functions of the machine are integrated in the remote controller.
This device can automate and/or control machine tools and production
machines in a simple and cost-effective manner.
Machine tools claims
What is claimed is:
1. A device for controlling a plurality of machine tools or production
machines, comprising: one handheld device located remote from the
plurality of machine tools or production machines and producing
control signals for controlling operation of the plurality of machine
tools or production machines; at least one respective ultrathin
client included in each of the machine tools or production machines
for converting the control signals from the one handheld device
into bus telegrams which include data for controlling drive components
for machine axes of the plurality of machine tools or production
machines, said least one ultrathin client lacking built-in intelligence;
and at least one bus system connecting the one handheld device with
the at least one ultrathin client to transmit the data and the control
signals between the one handheld device and the at least one ultrathin
client, wherein the entire intelligence, including the control software
for controlling the movement of the machine axes, is located in
the one handheld device, wherein for each of the oluraiitv of machIne
tools or production machines there exists in the control software
a control function program, wherein the machine axes movements of
each machine tool or production machine are controlled separately
by a corresponding one of the control function programs.
2. The device of claim 1 wherein the at least one bus system is
configured as a redundant and secure bus system.
3. The device of claim 1 wherein the at least one bus system is
implemented at an Ethernet bus system.
4. The device of claim 1 wherein the at least one bus system comprises
a secure wireless connection.
5. The device of claim 1 and further including a central electric
supply unit that supplies energy to the machine tools or production
machines.
6. A device for controlling a plurality of machine too1s or production
machines, comprising: one handheld device located remote from the
plurality of machine tools or production machines and producing
control signals, said control signals being the only signals that
control the operation of the plurality of machine tools or production
machines; at least one respective ultrathin client included in each
of the machine tools or production machines for converting the control
signals from the one handheld device into bus telegrams which supply
data for controlling machine axes of the plurality of machine tools
or production machines, said ultrathin client lacking built-in intelligence;
and at least one bus system connecting the one handheld device with
the at least one ultrathin client to transmit the control signals
from the one handheid device to the at least one ultrathin client
and transmit data from the at least one ultrathin client to the
one handheld device, wherein the entire intelligence, including
the control software for controlling movement of the machine axes,
is located in the one handheld device, wherein for each of the plurality
of machine tools or production machines there exists in the control
software a control function program, wherein the machine axes movements
of each machine tools or production machine are control separately
by a corresponding one of the control function porgrams.
Machine tools description
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the priority of German Patent Application,
Serial No. 103 04 903.7 filed Feb. 6 2003 pursuant to 35 U.S.C.
119(a) (d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a device for automating and/or
controlling machine tools or production machines, and more particularly
to a device that allows control of the machine tools or production
machines from a remote computer.
Great progress has been made over the past years to exchange data
directly between a supervisory computer and machine tools or production
machines, wherein production machines also include robots. In order
to achieve a high productivity, the machines must include a certain
level of intelligence. Productivity can be increased by incorporating
suitable automation and control technique. Whereas previously central
systems were employed, decentralized systems have begun to dominate
whereby an automation and control system residing in each machine
is connected via a bus system with the various components of that
machine. Productivity can be further increased by using communication
devices that connect the machines with each other and with a control
system.
A system of the aforedescribed type is shown in "NC-CNC Handbook",
Hans B, Kief, 1995/96 Karl Hansa-Verlag, Munich, Vienna, pp. 416
ff. The term DNC used therein refers to an operating mode wherein
several NC/CNC machines and/or production machines are connected
with a common central computer. According to the DNC concept practiced
today, all the control functions of the individual machines are
computed entirely on the internal hardware of the respective machine.
In earlier DNC systems, each machine performs a core control function,
with the central computer preparing or preprocessing the data used
by the core control.
It would therefore be desirable and advantageous to provide a simple
and cost-effective device for improving the automation and/or control
functionality of machine tools or production machines.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a device for automating
and/or controlling machine tools and/or production machines includes
one or more computers located remote from at least one of the machine
tools and/or production machines, wherein the computer(s) include
control functions for controlling the machine tools and/or production
machines. The device further includes one or more bus systems connecting
the computer(s) with each machine tools or production machine. Data
and control signals can be transmitted unidirectionally or bidirectionally
over the bus system(s). The remote computer is implemented as a
manual control device with integrated control functionality.
According to one feature of the invention, the computer can be
implemented as a standard personal computer (PC) or a notebook.
According to yet another advantageous feature of the invention,
the bus system can be made redundant and secure. This makes possible
a particularly high availability of the device.
According to another advantageous feature of the invention, the
bus system is implemented as an Ethernet bus system. The Ethernet
bus system is known to have a particularly high data throughput
rate.
The bus system can also be implemented as a wireless system with
secure connections which allows the user to be highly mobile.
Advantageously, the control function of several machines can be
processed in parallel on one of the computers. By using only one
computer for controlling several machines the device can be implemented
particularly inexpensively.
According to another advantageous feature of the invention, the
control functions can be distributed for processing over several
computers. Since a single computer may be overburdened by centrally
processing the control functions of a large number of machines,
distributing the various control functions over several computers
and processing the control functions can prevent bottlenecks.
According to yet another advantageous feature of the invention,
the machine can be provided with an UltraThinClient.TM. lacking
built-in intelligence. An UltraThinClient.TM. without built-in intelligence
which converts the user input into bus telegrams and receives the
incoming telegrams with information to be displayed (e.g., the pixel
data for a monitor) can be used in particular for locally controlling
the machine.
Advantageously, a central supply unit can be provided for supplying
energy to the machines. In other words, the supply units typically
associated with each machine can advantageously be combined into
a central electric supply unit to reduce costs.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the present invention will be
more readily apparent upon reading the following description of
currently preferred exemplified embodiments of the invention with
reference to the accompanying drawing, in which:
FIG. 1 is a block diagram of a first embodiment of a device according
to the present invention;
FIG. 1a is a block diagram of a second embodiment of a device according
to the present invention; and
FIG. 2 is a block diagram of a software architecture of a computer
used with the device of FIG. 1 or FIG. 1a.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the Figures, same or corresponding elements are
generally indicated by same reference numerals. These depicted embodiments
are to be understood as illustrative of the invention and not as
limiting in any way. It should also be understood that the drawings
are not necessarily to scale and that the embodiments are sometimes
illustrated by graphic symbols, phantom lines, diagrammatic representations
and fragmentary views. In certain instances, details which are not
necessary for an understanding of the present invention or which
render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to FIG. 1 there
is shown a block diagram of an automation and control system with
a handheld operating device BHG for numerical controllers which
is located remote from the machines 3a and 3b and connected via
a bus system 2 with the machine 3a and the machine 3b. The handheld
operating device BHG is not only capable of providing operating
and display functions, but also includes control functionality and
can therefore be viewed as a computer 1 that is adapted to the machine
environment.
Information can be entered, for example, via the key fields TF1
and TF2 a hand wheel HR and an emergency off-switch N. The data
can be visualized on a display D. The handheld operating devices
can be designed differently to satisfy ergonomic considerations.
An exemplary conventional handheld operating device is commercially
available from the company Siemens AG and distributed under the
name "Handheld Terminal SINUMERIK HT6".
Unidirectional or bidirectional data and control information is
transferred between the computer 1 and the machines 3a and 3b via
a bus system 2. An input/output (I/O) unit 4a which can include
several I/O modules (only one of the I/O modules 12a is labeled
in the figures for sake of clarity) and an UltraThinClient.TM. 5a
are integrated in the machine 3a. Corresponding I/O modules are
directly connected with sensors and actuators located in the machine
3a. Sensors can include, for example, rotation encoders, linear
transducers, acceleration sensors, switches, contacts and common
measurement systems. Actuators include, for example, the drives
of the machine. A corresponding I/O unit 4b which includes several
associated I/O modules (only one of the I/O modules 12b is labeled
for sake of clarity) and an UltraThinClient.TM. 5b are integrated
in the machine 3b. The machines 3a and 3b can in addition include
other components, which will not be described here and are of lesser
importance for understanding of the invention.
The entire intelligence of the described system, including the
control software, for example for controlling the movement of the
machine axes, are located in the computer 1. The computer 1 is connected
via the bus system 2 and the I/O units 4a and 4b with the sensors
and actuators of the machines 3a and 3b, respectively. They sensor
signal originating, for example, from the machine 3a is transmitted
almost instantaneously to the computer 1 providing the bus system
2 has a sufficiently high data throughput rate, and is further processed
by the control functions of the computer 1. Optionally, a corresponding
control signal is subsequently transmitted from the computer 1 via
the bus system 2 and the I/O units 4a and 4b to the actuators of
the machines 3a and 3b.
As mentioned above, the bus system 2 should have a high data throughput
rate. In practical applications, an Ethernet bus system has proven
to be suitable, whereby for the described applications the bus is
advantageously provided in duplicate. One bus is dedicated to operating
the sensors and actuators of the machine, which should be capable
of operating in real-time, whereas a second bus is dedicated to
controlling the system, which requires transmission of a large quantity
of data. Since the bus system 2 in the device of the invention is
an essential component of the machine control, the bus system 2
should be implemented redundantly to ensure a high level of availability
and safety of the data transmission.
If on-site operation is also desired, so-called UltraThinClient.TM.
5a and 5b can be used which lack built-in intelligence and instead
only convert the user input into bus telegrams and receive the incoming
telegrams, such display information (e.g., the pixel data for the
monitor). Process data can be visualized and changed, or data and
programs in the computer 1 can be accessed, by using an optional
additional terminal 10 which can be located remote from the machim
3a and 3b and the computer 1 and which can also be implemented an
UltraThinClient.TM. 5a and 5b.
The block diagram shown in FIG. 1 depicts two machines 3a and 3b
as well as one computer 1. However, embodiments with an arbitrary
number of machines are also feasible. If the computing power of
a single computer 1 is insufficient, then several computers can
be connected to the bus system 2 for controlling the machines, with
the control functions being processed in parallel.
FIG. 2 shows the software structure of the computer 1 in form of
a block diagram. The software structure is configured for the two
machim 3aand 3b and the computer 1 depicted in FIG. 1. The computer
1 is managed by an operating system 9. For each machine 3a and 3b
there adsts in the software a corresponding Human Machine interface
(HMI) server 6a and 6b, a corresponding control function program
7a and 7b, and a workplece program 8aand 8b, respectively. According
to the embodiment depicted in FIG. 2 the HMI server 6a, the control
function program 7a and the workplece program 8a are associated
with the machine 3a depicted in FIG. 1. The HMI server 6b, the control
function program 7b and the workplece program 8b are associated
with the machine 3b depicted in FIG. 1. A process control program
11 controls a supervisory overall process between the machines 3a
and 3b. The HMI server 6a and 6b is configured to manage and control
the associated UltraThinClient.TM. 5a and 5b which is located on
the machine 3a and 3b, respectively (see FIG. 1). The axes movements
of the machine 3a and/or 3bwhich are controlled, for example, by
an NC/PLC (Numerical Control/Programmable Logic Control) control,
are controlled for each machine separately by the corresponding
control function programs 7a and 7b, respectively.
A respective workpiece program 8a, 8b, including related data (e.g.,
tool correction data, tool geometry, etc.), is associated with each
machine 3a and 3b. In other words, a corresponding workpiece program
8a is associated with the machine 3b, and a workpiece program 8b
is associated with the machine 3b. The workpiece program 8a computes,
for example, the desired positions of the machine axes, which are
read on the input side by the control function program 7a and then
provided to an output. Likewise, the workpiece program 8b computes
the desired positions of the machine axes which are read on the
input side by the control function program 7b.
Employing a central control and automation device with decentralized
I/O units significantly reduces the portion of the automation technology
that has to be located within a machine. Accordingly, control boxes
located on-site close to the machines can be replaced by smaller
units or entirely eliminated. This is achieved by decentralizing
the drive components of the machine in the automation and control
device, while at the same time combining the electrical supply modules
for the different drive components of several machines in a central
electric supply device. For example, an intermediate circuit voltage
(typically 600V DC) which is typically already generated in each
machine from the AC current that powers the drive components, is
directly supplied to the machines from the central supply unit instead
of a three-phase AC current, as is customary today. Advantageously,
the energy which is dissipated, for example, in one machine for
braking a spindle, can be regenerated via an electric converter
and used directly to operate the other machines.
The bus system 2 is not necessarily a hardwired bus system 2 as
depicted in FIG. 1 but can also be implemented as a wireless network
2a, as shown in FIG. 1a. However, wireless networks 2a are known
to have more stringent security requirements. For example, a transmission
method can be used whereby the signals are securely transmitted,
processed and monitored over at least two channels and tested for
redundancy and cross-correlated to ascertain plausibility, as described
in DE 199 20 299.
While the invention has been illustrated and described in connection
with currently preferred embodiments shown and described in detail,
it is not intended to be limited to the details shown since various
modifications and structural changes may be made without departing
in any way from the spirit of the present invention. The embodiments
were chosen and described in order to best explain the principles
of the invention and practical application to thereby enable a person
skilled in the art to best utilize the invention and various embodiments
with various modifications as are suited to the particular use contemplated.
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