DE2906950C3 - Device for directing an external servomechanism onto a target object aimed at by a person - Google Patents

Description

The invention relates to a device for steering an external servomechanism onto one of one Target object aimed at person, in which the direction of rotation and inclination of the head of the person are used to determine the angular coordinates of the target object.

Such a device is known from US Pat. No. 3,769,636. This device is a mechanical one Connection provided on the one hand on the head of a person sitting in a wheelchair and on the other hand is attached to the wheelchair itself. This connection has articulated connections on which Probes are provided so that the amount and direction of rotation of the head and also its inclination can be determined. The sensors are electrically connected to a servomechanism through which the Movement of an element can be controlled.

From DE-OS 21 32 309 a device for measuring the viewing direction is known in which on the A contact lens is arranged which has at least one mirror around the eye of the observer reflect light incident on this mirror from a light source. With the help of the mirror reflected light beam can be the movement of the eye and in particular the cornea relative to a Determine the reference direction.

A similar device is from DE-OS 22 02 172 known for the automatic tracking of the pupil of an optical device with relative lateral movement between the eye pupil of an observer and ■> the pupil of the optical device serves on the head of an observer is a first optical device and a second optical device on the optical device Device attached A bundle of light rays runs between these two optical devices. if

into the pupil of the observer right on the pupil of the Optical device is aligned, a first signal is generated by the second optical device. If the observer's pupil is laterally displaced in relation to the pupil of the optical device, then so

r> there is also a corresponding, relative shift between the first and the second optical Device before, whereby the second optical device produces a second signal different from the first Signal generated and a servo device to

2!) Moving the optical device feeds. If that optical device has been adjusted to the position of the observer's eye pupil, generates the second optical device the first signal by which no tracking of the optical device is effected.

A general difficulty encountered with any target position measurement is that some external object is needed as a frame of reference. This requires that some sort of There is a connection between the external reference system and the system for measuring the position of the target object. In the device known from US-PS 37 69 636 is a purely mechanical connection between the A system for measuring the position of the target object and the external system, namely the wheelchair, is provided.

This connection affects the freedom of movement of the head of the wheelchair user to a great extent. at the devices known from DE-OS 21 32 309 and 22 02 172, a light beam provides the connection between the two systems. This also increases the freedom of movement of the head to which a light source or a mirror is attached, is severely restricted, since that emanates from the head The bundle of rays must be directed to a relatively small receiving area, which is generally not in the same line of sight as the targeted object.

It is therefore the object of the invention to develop a device of the type mentioned at the beginning in such a way that that a great freedom of movement of the establishment

■ 50 people using it and easy to use the facility are guaranteed.

This object is achieved according to the invention in that for measuring the direction of rotation of the head about the vertical axis a direction of rotation measuring device responsive to terrestrial magnetism is provided and the inclination of the head can be determined by an inclination measuring device which measures the deviation from the horizontal.
A particular advantage of the invention is that on the one hand the earth's magnetic field and on the other hand the effect of gravity are used as the external reference system. The magnitude and direction of rotation of the head is determined by a direction of rotation measuring device attached to the person's head and responsive to the magnetic field. The inclination of the head is determined by an inclination measuring device, which is also attached to the head of the person and is responsive to gravity in a known manner.

Due to the special choice of the reference system, no mechanical connection to the reference system is required, and only electrical connection lines are required between the measuring devices attached to the head and a servomechanism! Since these lines can be designed flexibly as required, the movement fn. ^: hay of the person's head does not affect.

In the device according to the invention, it is also possible to control the servomechanism to determine the required sizes by directly aiming at the target object, what in the event of a use a light beam as a link between the system for position determination and the Reference system is generally not the case.

The operation of the device according to the invention is extremely simple because the free rotation of the Control measures necessary for the movement of a servomechanism are taken can. The device according to the invention can advantageously be used to actuate artificial limbs, such as B. an artificial arm can be used.

Advantageous further developments of the invention emerge from the subclaims.

The invention is described below with reference to a preferred exemplary embodiment explained in more detail on the drawings. It shows

F i g. 1 and 2 are schematic circuit diagrams of a preferred embodiment of the invention,

F i g. 3, 4 and 5 timing diagrams of some important ones in the circuit of FIG. 1 and 2 occurring signals.

F i g. 6 is a flow diagram illustrating the overall operation of the circuit;

7 to 12 are flowcharts explaining the operation section by section in detail;

F i g. 13 is a graph for definition in the description of occurring physical values,

F i g. 14 the graphic representation of a target pattern and

15 is a graphic representation of a display unit.

At the beginning, the principle of the optical sighting device according to the invention will be explained with reference to FIG. The line NS shows the north-south course of the earth's magnetism. X-Y-Z are angular coordinates, with the X and K axes defining the horizontal plane and the Z axis defining a vertical plane. The coordinates are set at the beginning so that the standard viewing direction Ο— Υ forms an initial viewing angle Θ _ο with respect to the line NS.

The eyes of the operator at the origin O look at the target object located at the point VV from a distance R. The point W forms with the line NS a horizontal viewing angle Θ and a vertical viewing angle Φ based on the horizontal plane.

Da uses the horizontal component of terrestrial magnetism to calculate the position of a target object becomes the output (cos Θ) of a direction sensor using the following Modified formula:

Ml - f Sin 1 · Sin Φ cos Φ

whereby

= Horizontal component of terrestrial magnetism = total terrestrial magnetism

Ml = sensor output variable (cos b)
I = magnetic inclination

When the operator looks at the target object located at the point VV (x, y. Z) with both eyes, the values X, Y and Z can be expressed by the following equations:

V - Λ cos Φ, ■ si

) = / (cos «*), cos!«, - (-) ")
/ = R Sin Φ,

where R is the Absland / between O and H and can be expressed by:

Ä =

cos Φ Sin (W, - HO

: i> with a being the distance between the centers of the operator's eyes and 02 being the horizontal viewing angle measured from the line NS when the operator is looking at the target object with one eye. The following operations are performed to calculate the equations given above:

(1) Establishing a standard viewing direction in order to obtain an initial viewing angle Θο.

(2) Looking at a target object with both eyes to a first horizontal viewing angle Θι and a vertical viewing angle Φι to get.

(3) Looking at the same target with one eye for a second horizontal viewing angle Θ? to obtain.

Once a standard viewing direction O- Voestimmt and determines the positions of other target objects may be prepared by repeating the above Operatioen (2) and are calculated (3).

When an artificial arm is directed to move towards the target object, the next can be the Height of the target object can be calculated using the following equation, if the length and a running vertical angle of the artificial arm are known:

ZH - (L ₁ sin «+ /.,sin/i)

whereby

= the length of the upper section of the artificial

Arms.
Li - the length of the lower section of the artificial

Arms.
λ - the vertical angle of the upper portion of the

artificial arm.
β = the vertical angle of the lower portion of the artificial arm.

Further, since the distance R can be obtained by using the third equation of (2), if the height ζ and a vertical viewing angle Φ \ are known, the values X and Y can be obtained using the remaining equations of (2). In this case, the following operations are performed to calculate the above equations:

(1) Establishing a standard viewing direction in order to obtain an initial viewing angle Θο.

(2) Position the artificial arm on the target object to obtain a height ZH .

(3) looking at the target object with both eyes at a horizontal angle Θ; and to get a vertical angle Φ \ .

Once a standard viewing direction has been determined and established, the positions of other target objects can can be calculated at a constant height by merely repeating the above operation (3).

The positions of various target objects are thus repeatedly calculated and sent to the control system of the artificial arm is transmitted so that the artificial arm moves by engaging the viewed Follows target objects from point to point.

Another feature of the preferred optical sighting device of the present invention consists in identifying 17 types of surface sections on a target object, so that 17 signals that correspond to the respective target area sections, can be switched as a substitute for 17 key switches can be used to issue commands to an external control system. The table below shows an example of commands in which six electric motors are operated.

stop engine Λ / 2 1/3 1/4 MS Mb normal M \ 3 6th 9 C. r command Backward 0 4th 7th A. D. Base 1 S. R. R. F. _ 2

14 shows a target pattern with 17 target surface sections, to generate 17 command signals.

Fig. 15 shows a glasses type display unit for visually displaying the 17 kinds of command signals recognize. 17 photodiodes are mounted on the display unit, each of which corresponds to the respective one Target area section according to FIG. 14 is arranged.

In the following, the invention will be explained further with reference to the schematic circuit diagrams. As one can see from FIG. 1 the sensor section 1 comprises a pair of direction sensors 1 a and 16 which detect the rotation of a person's head about the vertical axis. Inclinometers lc to if record the inclination of the head. The inclinometers are of the type in which torque compensation takes place when the magnet is moved.The direction sensors la and 16 are attached to the head of the person concerned and arranged at right angles to each other.They record an angle Θ between a direction of vision and the geomagnetism in the form of the functions sin 0 or cos Q.

A pair of inclinometers Ic and \ d are attached to the head to detect an inclination angle Φ of the direction sensors with respect to the horizontal axis as functions of sin θ and cos Φ, respectively.

The inclinometers Ie and If are attached to the artificial arm in order to detect the angles oc and β of the upper and lower portions of the artificial arm with respect to the horizontal plane as functions of sin α and sin β.

An input control section 2 comprises an input multiplexer 2z which detects input signals from the sensor section 1 and an A / D converter 26 which converts an analog signal into a digital signal

A data control section 3 includes a multiplexer controller 3a, which generates selection signals for the input multiplexer 2a, and a memory addressing device 36, which generates address signals for the memory section 4 where input signals are stored. An operating control 3c is also provided, which controls the memory input and operating signals

in ®, ® , ®, ®, © and Derzeugt.

The memory section 4 contains four memory blocks, namely memory-0, memory-1, memory-2 and memory-H.

A data modification section 5 contains computers

r, 5a. 5b and 5c, which modify input data received via the directional sensors.

A position calculating section 6 includes computers 6a and 6b. which calculate the sine and cosine functions, as well as calculators 6c, 6c /, 6e and % f. which calculate the distance R or the angular coordinates X, Kund Z.

A height calculating section 7 is used to calculate the positions of various target objects that have a constant height. Of the

2> Section 7 contains a computer 7a which calculates a height ZH of a target object using the input data sin α and sin β . A calculator Tb calculates a distance RH (which is equivalent to the distance R) using the calculated data ZH.

So a display section 8 amplifies that of the Operation control 3c incoming operating signals to set the processing or process operating modes 0, 1, 1.1, H. H.H and S. to display.

As one can see from FIG. 2, contains a direction indicator

3 · -, calculating section 9 calculators 9a and 96 which calculate the sine function using the in the memory section 4 stored data and that coming from the data modification section 5 modified Get data.

4n a directional discriminator section 10 contains Multiplexers 10a and 106. select the horizontal and vertical limit values, respectively. Sequence counter 10c and 1Od generate selection signals for the multiplexers 10, and comparators or comparators 10e and 10 / compare the data coming from the computers 9a and 96 with the horizontal and vertical limit values, respectively.

A decoder section 11 outputs 17 signals respectively the direction identified by looking.

The operation of the preferred optical sighting device is described below with reference to the pulse diagrams (Fig. 3 to 5) and the soot diagrams (Fig. 6 to 12) in connection with the schematic circuit diagrams (Figs. 1 and 2) will be explained.

If a command Jö] is input into the multiplexer control 3a according to FIG. 3, the system is initialized to assume a process or processing state 0, and multiplexer control signals © and © are generated (see also FIGS. 1 and 6) . The input multiplexer 2a samples the input signals sin θο, cos 0 & sin Φο and cos Φα one after the other and emits a series of analog signals ®. The signal ® is converted in the A / D converter 26 into a serial digital signal ©

According to the Jg] command is in the operation control 3c Speicherauswahlsigna] © generated so that in the storage of the memory section 4 O

is selected. The memory addressing device Zb successively generates address signals ©, ©, © and © from the signals © and ©, so that the serial digital signal © is stored in the memory-O.

When all the input data (which were present in the form of a serial digital signal) are stored in individual sections of the memory-O, the operation control 3c emits an operating or operation signal ®, and the calculation for modifying the input data Θο takes place in accordance with equation ( 1) instead. Fig. 7 is a flow chart showing the processing procedure in the O process mode explained above.

As one can see from FIG. 6, the controller assumes the “waiting” state. when the process O is completed. If a command [TJ is issued to calculate the position of a target object, the process mode changes to 1 and input signals sin Θι, cos 0t. sin Φ] and cos Φι are scanned and stored in memory-1 in the same way as in process 0, with the exception that the operation control 3c sends a signal

© emits instead of the signal © in the previous process mode. In the computer 5b following the signal © emitted by the operation control 3c, the data from cos Θι are modified. Fig. 8 is a flow chart showing the processing procedure in process mode 1 explained above.

Consider FIG. 6 again. The controller assumes the "waiting" status when process 1 is completed. In turn, is the command | TJ issued, the process mode proceeds to 1.1, and input signals sin 0 ₂ cos 02, sin Φ2 and cos Φ2 are scanned and stored in the same way as in the case of the process mode 1 in memory 2, with the exception that a signal © is output by the operation controller 3c instead of the signal © in the previous process mode. In the computer 5 c following the operating signal ® emitted by the operation control 3 c, the data of the cos. Θ2 modified

After a certain delay, in which the data for cos 02 are modified, the computers 6a, 6b and 6c are activated so that the functions sin (Θι -Θο), cos (Θι -Θο) and R in the equations ( 2) and (3) can be determined. After a further delay time, computers Bd, 6e and 6 / are activated so that equations (2) are calculated. The calculated values of X, Y and Z are given to the external control system for the artificial arm to aim the arm at the target object. Fi g. 9 is a flowchart showing the processing operation in process mode (Q) explained above

If (see FIG. 6) the command © is given following the process 11 in order to calculate a height ZH of the target object using the data, the process mode changes to H , memory selection and address signals ©, © and ® generated, and input signals sin α and sin. β are scanned and stored in memory Η. When the data are stored, the signal ® is given to activate the computer 7a Tim so that the equation (3) is calculated. F i g. Fig. 10 is a flowchart showing the above processing procedure in the if process mode

Referring again to FIG. 6, it can be seen that control passes to the "wait" state when process H is complete. If the command üTJ is issued again, the pre-process mode goes over

ϊ according to H.H, and input signals sin Θι, cos Θι, sin Φι and «« Φι are scanned and stored in memory-1. The operating signal © is then emitted in order to modify the data cos Θι.

After a certain delay time, the computers 6a, 6b and Tb are activated so that the functions sin (Θ, -Θο), cos (θι -0 _O ) and RH (= ZH / sin Φ,) are calculated. After a further time delay, computers 6d and 6e are activated so that equations (2) are calculated for X and Y , this time using RH as R. Then the values X and Y together with a constant height ZH are sent to the external control system for the artificial arm in order to direct the arm towards the target object. F i g. 11 shows the above-described process in process mode HH in the form of a flow chart.

If the command [s] is finally given, input signals sin θι, cos Θι, sin Φι and cos Φι are sampled and stored in memory-1 in the manner explained above. The operating or operational signal © is output in order to modify the data Θι, and after a certain delay time the computers 9a and 9b are modified by the signal © so that the functions sin (Θι - Θο) and sin (Φ1-Φ0) be determined. After another

jo time delay following the signal © becomes a Signal © is generated and the sequence counters 10c and 10c / are started.

Limit values for target area sections on a target pattern are expressed as sin (-25 °), sin (-10 °), sin (10 °) and sin (25 °) is provided for each horizontal and vertical viewing angle. These values are sequential in the multiplexers 10a and 10Zj controlled by the sequence counters 10c and 10c /, respectively.

The data for the viewing angles coming from the computers 9a and 9b are compared one after the other, starting at sin (−25 °), with each limit value in the comparators 10e and 10 /. If the input data is found to be less than a limit value, the corresponding sequence counter is stopped. If both sequence counters are stopped, the contents of the sequence counters in the decoder section 11 are decoded into 17 output signals and from these the output signals "0" to "9", "A" to "F" and "BASIS" are sent to a corresponding photodiode in the is sent to the display unit shown in Fig. 15 to confirm the targeted or viewed target area.

If correct sighting is confirmed, the command m is given again and the output signal is given to the external control system to be used for command purposes.

Fig. 12 is a flow chart showing the above-explained, taking place in the process mode S illustrates operations

Although in the embodiment explained above, the system according to the invention in combination with the The mechanism of an artificial arm has been explained, of course, has application to others artificial limbs possible.

In addition 12 sheets of drawings

Claims (4)

Patent claims: 1. Device for directing an external servomechanism on a target object aimed at by a person, in which the direction of rotation and inclination of the head of the person is used to determine the angular coordinates of the target object, characterized in that for measuring the direction of rotation of the head about the vertical axis a Direction of rotation measuring device (la, \ b) responsive to geomagnetism is provided and the inclination of the head can be determined by an inclination measuring device (lc, id) which measures the deviation from the horizontal 2. Device according to claim, characterized in that the direction of rotation measuring device has a Parr directional sensors (la, 16, 'and the inclinometer has a pair of inclinometers (lc, id) which can be fastened to the head of the person, whereby a head posture of the person can be determined is when the person is aiming at a target object. 3. Device according to claim 1 or 2, characterized in that at least one additional inclination measuring device (Id, ic) is provided on the external servo mechanism in order to determine the altitude of a target object when the external servo mechanism has moved to the target object. 4. Device according to one of claims 1 to 3, characterized in that a circuit arrangement (9, 10, 11) to distinguish different sight angles is provided that each of the different Sighting angle is assigned to a certain area of a given sample field, and that when aiming at an area of the pattern field by the circuit arrangement (9, 10, 11) a signal assigned to this area can be generated.