UniForce
Six axis Force-Torque
(FT) sensing is primarily used in the field of industrial
automation, especially robotized assembly and manufacturing.
Wrist mounted FT sensing plays important role in
getting information on the effects the robot manipulator
is exposed to. The 6-axis FT transducer is a device
aimed at measuring FT vectors at any selected point
of the space in terms of their x, y, z axes in a
Cartesian coordinate system attached to the body
of the transducer.
The UniForce 6-axis
FT sensor system is a DSP powered high performance
peripheral device with standard digital and analog
interfaces. The UniForce system contains two primary
parts: the 6-axis FT transducer and the Signal Processing
Unit (SPU). The transducer operates on tensiometric
principle having a special metal spring on which
strain gauges are stuck at adequate points. Based
on the inherent processing power and communication
speed, the SPU can act as a high performance slave
sensor device of a host controller. The SPU provides
a variety of real-time signal processing tasks including
digital filtering, reference point and cross-coupling
correction, coordinate transformation etc. Main
features of the SPU are as follows:
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DSP based
hardware architecture for high performance
FT data processing.
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Configurable
RS-232 or RS-422 asynchronous serial host
connection.
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Six channel
±10V or ±5V DAC outputs for
analog FT representation.
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4 + 1 bit
wide digital synchron interface.
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8 kHz internal sampling rate
for the six FT channels. |
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Fixed point or IEEE-754 floating
point FT data representation. |
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Message based communication
protocol. |
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Non-volatile storage for user
defined data structures. |
The main task of the
SPU is to provide the output vector of the six preprocessed
FT axes at max. 1kHz rate. A mask vector enables
the host to select only those axes which are of
particular interest in a given task. Data transfer
can be synchronous where the transfer of data messages
is scheduled by the host device, or asynchronous
where data message transfer is scheduled by the
SPU. Well defined communication protocol enables
the host to call all services on the fly. As an
example, the host can select the required output
sampling rate, update FT reference point, choose
between synchronous and asynchronous mode of processing
and initiate or terminate FT data transfer.
The UniForce system
has been developed in cooperation with TÁRA Electronics
Ltd. Our company has provided the complete system
specification, hardware design of the SPU, development
of the measuring algorithms and DSP programming.
The 6-axis FT transducer family is the product of
TÁRA Electronics.
