DE19509680A1 - Hand-movement detector for three=dimensional data-glove input to computer and robotics - Google Patents

Abstract

The detector comprises a retaining glove, equipped with sensors and worn on the hand. The sensors (2) detect static (OHz) and dynamic (greater than OHz) accelerations caused by hand movements and position or deflections of the hand. A pre-amplifier (3) and filter (15) and a signal converter (13) are provided for pre-processing the measurement signals, and a screening device (5) is provided for selecting signals for transmission at the measurement converters (6, 14), which convert the analog signals into digital values. A computer receives the data directly or indirectly from the measured values converters (6, 14).

Description

The invention relates to a device for location - independent detection of Hand inclinations and movements. The device can be used to enter three-dimensional inclination and movement data in computer systems as well as for Control tasks in the field of robotics, industry, space travel and medicine (e.g. to control the visualization of medical image data). Due to its inherently high temporal resolution, it is particularly suitable for Detection of human hand movements, such as z. B. generated by the deaf.

The invention can also be excellently used with any of those available on the market Data gloves combine and expand their range of applications and services considerably.

The invention is in the technical field of human-machine interfaces three-dimensional input devices for data processing systems and the three-dimensional positioning systems. It can also be the area of Assign data gloves (to English "datagloves"), since these are usually a 3D Use location system.

The determination of the three-dimensional position and orientation of an object in space is a common task in engineering, and there are a variety of solutions to solving it Devices there. Their physical operating principle is mostly based on the measurement of Intervals that are determined by determining signal transit times or intensities will. The signals are e.g. B. electromagnetic or acoustic nature.

• - The Polhemus sensor (Polhemus, 3 Space user's manual, A Kaiser Aerospace & Electronics Company, May 1987) contains three coils arranged perpendicular to each other, which serve as receivers. At a fixed reference point there are three transmission coils that are also perpendicular to one another and emit an electromagnetic field. Its intensity is measured in the receiver coils, from which the position of the receiver can be calculated. A similar device is the "The Flock of Birds ^TM " (The Flock of Birds ^TM , Position and Orientation Measurement System, Installation and Operation Guide, May 25, 1993, © 1993 Ascension Technology Corporation, POB 527, Burlington, Vermont 05402).
• - The GP-8-3D (Three Dimensional Sonic Digitizer Model GP-8-3D, Science Accessories Corporation, Southport, CT) works on the basis of ultrasound measurements which determines the signal propagation time and triangulates the position of the transmitter is detected. For this purpose, several receivers are arranged in the vicinity of the transmitter Register the pulses emitted by the transmitter. The 3D ultrasound mouse from Logitech (c′t - magazin für computertechnik, May 1992, p. 37) works on the same principle.
• - The GPS (Global Positioning System) (e.g. described in: Precise Tracking of Remote Sensing Satellites With the Global Positioning System, Yunck, T.P., Sien-Chong Wu, Jiun-Tsong Wu, Thornton, C.L., IEEE Transactions on Geoscience and Remote Sensing, Volume 28, Issue 1, January 1990) is a global navigation aid system in which the Earth orbit satellites, whose position is known exactly, highly accurate Broadcast time signals. The recipient whose position is to be determined can based on the transit time differences of the signals from four different satellites calculate spatial coordinates to the meter.
• - A system has been developed at Siemens (Maggioni, C., A Novel Device for Using the Hand as a Human Computer Interface, Proceedings of the HCI, 1993, England), which allows the movements of one hand to be recorded using a video camera to record and measure a limited spatial area. This will be Principle of optical triangulation used.
• - The SpaceBall (e.g. described in: A test bed for virtual reality components for Support for medical applications, Faulkner, G., Krauss, M., Workshop Digitale Image processing in medicine, University of Freiburg, 2.-3. March 1994) uses a completely different principle. The ball-shaped device determines the Torsional, thrust, compressive and tensile forces that the user applies to the hand Exercises input ball. This allows - with a spatially stationary input device - Rotation and translation vectors for further computer-aided processing to generate.
• - In US Patent 4,414,537 a glove is described, the hand inclinations and jerky hand movements extremely rudimentary using mercury and Inertia switches determined.  
• There are also some with particular reference to the intended field of application of the invention to name the devices commonly known as "data gloves":
• - The TUB sensor glove (DE-Patent 42 40 531) was designed by the inventors and built. Sources for related devices can be found in the cited patent.
• - The VPL-DataGlove ^™ (US Patent 4,988,981) is a widely used commercial input device for human finger movements.

These are for the location-independent recording of hand inclinations and movements previous systems have various shortcomings that they have for this purpose to make something useless.

All previous systems (exception: US Patent 4,414,537) always require external ones Reference points, e.g. B. in the form of ultrasound receivers with a known position must be provided so that the location of the transmitter is calculated using triangulation can be. This is directly contrary to the requirement of being independent of location. The GPS can be used anywhere on earth, but its resolution (Meter range) too small to be able to detect hand movements. The The Siemens system requires a stationary camera. The SpaceBall is also for set up stationary operation. Hand movements e.g. B. in the sense of dynamic Signs of the deaf cannot be recorded with it.

The need for external (= not at hand) tools for the Inclination and movement measurements increase the space requirement of previous measuring arrangements and thereby limits their area of application.

The input device described in U.S. Patent 4,414,537 determines its spatial Orientation without external aids, however, the inclination of the hand or hers Motion measured using the mercury and inertia switches only in binary form become (inclination - no inclination; jerky movement - no movement). Continuous movements with a large dynamic range cannot be recorded.

There are also devices operating with electromagnetic fields the basic problem that the position measurements z. T. sensitive by in  nearby metal objects and jammers such as video monitors to be influenced.

When locating with ultrasound, air turbulence increases with distance between transmitter and receiver for rapidly increasing measurement errors. Especially with Ultrasound also has the basic difficulty that only low measuring rates are possible because the speed of propagation of the sound waves in each limited physical medium (mostly air) and - compared to the Speed of light - is low.

The invention was based on the object, mobile hand inclinations with good angular resolution and hand movements with high temporal resolution too to capture. This is e.g. B. particularly necessary if the very rapid gestures Deaf people should be taken in, the test subjects not by cable and a range of motion restricted by the input device can be obstructed allowed to.

This object is achieved with the features specified in claim 1. Beneficial Further developments of this solution contain the subclaims.

The defects inherent in the state of the art with regard to the task at hand are eliminated by the invention.

The system works regardless of location, since it does not have any fixed, external reference points or aids other than gravity (the energy supply can take the form of of batteries carried as required and the coupling to other computers using infrared or radio data transmission can be solved). This makes the invention more and more different Applications more accessible than today's stationary systems. The device has one very small space requirement and good angular resolution due to the sensors used in the case of hand inclinations as well as a high temporal inherent due to the measuring principle of the sensors Resolution with continuous hand movements (with those in the preferred version sensors used are measuring rates up to several 1000 measurements per second possible). The system is insensitive to acoustic and electromagnetic Disorders.

In combination with conventional location systems, the use of the Device whose measurement resolution and usability, in particular other,  So far only indirectly derived information about human hand movements through direct measurement available.

The invention can, for. B. also good for controlling 3D CAD systems. When working with a 3D CAD system, the orientation of the view must be frequent change. So far, this has been done with knobs for the individual axes of rotation solved, which was not very intuitive and increased the training time. With this one described invention can easily orient such three-dimensional objects and can be changed very easily.

A preferred embodiment of the invention is shown in the drawings and is described in more detail below.

Show it

Figure 1 is a semi-spatial view of the system on hand.

Fig. 2 basic options for sensor arrangement;

FIG. 3 shows the basic circuit of the device;

Fig. 4 shows a detailed circuit for evaluating an inclination and movement sensor;

Figure 5 is a detailed circuit for evaluating a motion and vibration sensor.

Fig. 6 is an alternative circuit to the sensor input;

Fig. 7 shows another alternative circuit for the sensor evaluation.

The example shown is only one way of carrying out the invention. Of the One skilled in the art can easily see how similar devices can be made without to change the character of the invention.

Fig. 1 shows a semi-spatial view of the system on hand. You can see a human hand 1 , on which the device by means of suitable holding devices - z. B. by means of a belt or a glove - to be fastened. The device mainly consists of acceleration sensors 2 , which record accelerations in one axis direction (x, y, z). Associated with them are one or more amplifiers 3 , which forward their signals via a connection 4 to further evaluation stages (cf. FIG. 3).

Fig. 2 shows the principle of an advantageous embodiment of the invention, in which a plurality of acceleration sensors x _1,2,3 , y _1,2,3 , z _{1,2,3 are arranged} together to coordinate systems 10 , 11 , 12 , which are also mutually can be skewed. They are at fixed intervals (k _1, 2, 3 ) and fixed orientation with respect to an imaginary reference coordinate system 9 , which is on hand together with 10 , 11 , 12 . The purpose of this arrangement is, in particular, to be able to better detect rotary movements of the hand by means of differential measurements using the differently placed sensor systems.

It is also possible and, in the preferred embodiment of the invention, also realized (cf. FIGS. 4, 5) to arrange different types of acceleration sensors together on hand in order to expand the dynamic range. In the specific case, sensors from Analog Devices (ADXL50), which can measure static accelerations from 0 Hz (e.g. gravitational acceleration → inclination measurement) to several 100 Hz (vibrations), were used with sensors from Kistler (a triaxial accelerometer 8692B5 with a wide range and dynamics) combined to be able to detect hand inclinations with good angular accuracy on the one hand, but also dynamic hand movements with high temporal resolution and good accuracy by means of the measured accelerations.

Last but not least, the use of several different sensors increases the redundancy of the Systems, which can further increase the accuracy of the measurement results.

Fig. 3 gives an overview of the main electronic components of the device. Accelerations measured by one or more sensors 2 are converted into electrical signals by them and preamplifier stages 3 are supplied. The amplified signals can then either be fed directly to A / D converters 6 or first passed through a multiplexer 5 , the output of which is connected to an A / D converter 6 . The A / D converter 6 is connected to an evaluating computer 7 , which controls it and further processes or forwards the data. Of course, it is also possible to make changes to this scheme without changing the character of the invention. For example, it could It may make sense to connect the multiplexer 5 directly to the sensors 2 in order to save circuitry for the preamplifiers 3 (in this case, at most one preamplifier 3 between the multiplexer 5 and the A / D converter 6 would be necessary).

Fig. 4 shows in detail the circuit of a preamplifier stage 3 a, which is connected downstream of an acceleration sensor 2 a (. Eg a ADXL50). Depending on the sensor, precautions are required for scaling (amplification or attenuation) of the sensor signal and a zero point correction. It may also be that the signal must be filtered, which is only indicated in the drawing by a capacitor 15 . The processed signal is forwarded to the (analog) multiplexer 5 or directly to the A / D converter 6 .

FIG. 5 contains a circuit which is very similar to that of FIG. 4 in terms of function and design. Between acceleration sensor 2 b (e.g. a Kistler 8692B5) and amplifier 3 b, only a sensor supply and signal isolation stage 8 was added to take into account the 2-wire supply of the sensor. Since the signal is coupled out capacitively, there is no need for a variable zero point adjustment. The processed signal is also fed to the (analog) multiplexer 5 or A / D converter 6 .

Fig. 6 shows an alternative circuit for the sensor evaluation, in which the signal supplied by the acceleration sensor 2 and amplified by the preamplifier 3 signal is transformed in the converter 13 into a frequency signal before it through the multiplexer 5 (sufficient time, a normal digital multiplexer) to a frequency counter 14 is forwarded to be finally digitized there. This variant is particularly suitable if the sensor signal is to be sent over longer distances before it is finally digitized, since a frequency signal is far less susceptible to interference than an amplitude-modulated signal.

Fig. 7 is intended to illustrate, wherein the signal supplied by the acceleration sensor 2 is directly converted (via a suitable converter 13) to a frequency signal and sent via a multiplexer 5 to the frequency counter 14, a further variant embodiment. The frequency signal can also arise directly in the sensor 2 (the converter 13 would then be located in the sensor and would be part of the signal preprocessing on site - for example "on chip").

Claims (18)

1. Device for location-independent detection of hand inclinations and movements, consisting of a sensor provided with sensors to be attached to the hand, such as. B. a glove, characterized by the following combination features:

• - Sensors ( 2 ) which detect static (0 Hz) and dynamic (<0 Hz) accelerations from the hand position or inclination or from the hand movements;
• - Preamplifier ( 3 ) and filter ( 15 ) and / or signal converter ( 13 ) for preprocessing the measurement signals;
• - Selection devices ( 5 ) for selecting the signals to be transmitted to the transducer ( 6 , 14 );
• - Transmitters ( 6 , 14 ) which convert the analog signals into digital values;
• - One or more computers ( 7 ), which convert the data directly or indirectly from the measured value ( 6 , 14 ).

2. Device according to claim 1, characterized in that any number of acceleration sensors ( 2 ) is used, so that in particular rotational movements such. B. can be better detected by differential measurements and the accuracy of the measurement results can be increased by increased redundancy in the resulting data. 3. Apparatus according to claim 1, characterized in that the acceleration sensors ( 2 ) are arranged in different ways to meet the respective measurement requirements. 4. The device according to claim 1, characterized in that accelerometers ( 2 ) of different types are used in order to cover un different measuring ranges. 5. The device according to claim 4, characterized in that the different acceleration sensors ( 2 ) z. B. are inclination and vibration transducers. 6. The device according to claim 1, characterized in that the following on the acceleration sensors ( 2 ) electronic signal processing ( 3 , 15 , 13 ) and signal selection ( 5 ) combined in a suitable manner and adapted to the acceleration sensors ( 2 ) used in each case. 7. The device according to claim 1, characterized in that that the signals to be processed are analog voltages and / or frequency signals. 8. The device according to claim 1, characterized in that the selection device ( 5 ) for the voltage signals consists of analog multiplexers. 9. The device according to claim 1, characterized in that the selection device ( 5 ) for the frequency signals consists of digital multiplexers. 10. The device according to claim 1, characterized in that the transducer ( 6 ) is an A / D converter. 11. The device according to claim 1, characterized in that the transducer ( 14 ) is a frequency counter. 12. The apparatus according to claim 1, characterized in that the multiplexer ( 5 ), A / D converter ( 6 ) or frequency counter ( 14 ) can be controlled in a suitable manner by the computer ( 7 ) and can communicate with it. 13. The apparatus according to claim 1, characterized in that the computer ( 7 ) can evaluate the measured data and / or transmit it to other computers. 14. The apparatus according to claim 1, characterized in that sensors ( 2 ), preamplifier ( 3 ), signal converter ( 13 ), filter ( 15 ), multiplexer ( 5 ), A / D converter ( 6 ), frequency counter ( 14 ) and Computers ( 7 ) can be arranged with respect to the hand in a manner corresponding to the respective measuring task. 15. The apparatus according to claim 14, characterized in that the sensors ( 2 ), preamplifier ( 3 ) and / or signal converter ( 13 ), filter ( 15 ), multiplexer ( 5 ), A / D converter ( 6 ) and / or Frequency counter ( 14 ) are attached to the hand together with the computer. 16. The apparatus according to claim 14, characterized in that the sensors ( 2 ), preamplifier ( 3 ) and / or signal converter ( 13 ), filter ( 15 ), multiplexer ( 5 ), A / D converter ( 6 ) and / or Frequency counters ( 14 ) are attached by hand and connected to the computer by a suitable transmission device (by cable, wireless, optical). 17. The apparatus according to claim 1, characterized in that the holding device for the sensors ( 2 ) and the evaluation electronics is a suitably shaped glove. 18. The apparatus according to claim 1, characterized in that the holding device for the sensors ( 2 ) and the evaluation electronics is a suitably shaped belt or strap.