FI88205B - Procedure for determination of angular position - Google Patents

Description

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The present invention relates to a method for determining the angular position and to an electronic compass with a digital and / or analogue display used in the method.

5 The compass is an instrument used to determine the direction of the main air.

Depending on how it is used, it acts as a control or guidance passport.

In principle, a compass consists of a housing with a so-called pin placed in the middle of the base. This is a vertical metal pin with a hard metal tip on top of which a compass rose or magnetic needle is placed. A compass rose most often has a double distribution at the edge, namely an inner one with lines, a compass rose, and an outer one with degrees. This drops from 0 ° to 360 ° from north to east.

A compass with an annular scale which rotates simultaneously with the compass needle is also known. The degrees are read using the built-in prism, so the compass must not be held diagonally when reading, otherwise the compass needle will get stuck, leading to erroneous readings. The accuracy of this compass is about 5 °.

Despite the fact that the horizontally oscillating magnetic needle always adjusts according to the isogon, which forms an angle with the geographical meridian called the declination or compass deviation, all mag-25 rivet compasses indicate a magnetic or divergent direction.

The differences between the mentioned compasses can be seen e.g. in that they do not have far too high measurement accuracy, as visual reading of the scale produces some effort. Another disadvantage of known compasses is that they only function properly at a small angle of inclination. The compass points differently in all cases, so that depending on the location, the correction must be made by increasing or decreasing the deviation.

According to European application 0 078 510, a clock with a pointer setting for hours and a device for determining the direction in a magnetic field is known.

A difference with this invention is the use of a completely different sensor principle in this application.

2 8820ό

The rate of interpretation depends on the excitation of the sensors, which is not the case with the present invention, so as to provide a simplification with regard to publication 0 078 510, which is to be called a real progress. In contrast to 5 in 0 078 510, the peak detector is at a crucial time, i. at maximum value in the northern or southern passage at its most sensitive so that possible sources of error can be reduced to a minimum. In addition, no constants are required in the present invention and this is in contrast to publication 10 078 510, so that no precision components or combined sensors are required. According to the present invention, the inclination correction as well as the position sensitivity are corrected automatically, which is not the case in publication 0 078 510.

European application 0 091 000 discloses a device for measuring the Earth's magnetic field as a navigation aid for a vehicle driver, in particular for urban navigation. As shown and explained, it has been shown that this is another sensor principle that does not have a bridge connection and which, when the vehicle is tilted, falsifies the result, as these three sensors are not a measure of the horizontal level required for course determination. The electronic and mechanical switching solution has not been explained at all. This system does not work in the vehicle, as there is clearly no deviaa-25 thio measurement or repair. Similarly, the necessary correction of the location deviation has not been mentioned or explained.

According to European Patent Publication 0 120 691, an electronic digital compass is disclosed, in which case it must be stated that measurement errors 30 caused by temperature changes cannot be compensated, that slope errors cannot be avoided by a magnetic field sensor and thus no slope independence exists. The temperature measurement only works to indicate the outdoor temperature. For navigation tasks, this device is definitely inadequate and too inaccurate, as the course solution is limited to 45 ° steps only and does not allow any 450 times more accurate solution of the course, so that the solution of very precise navigation tasks is therefore impossible. . The possibility of measuring local amplitude change has not been presented at all, nor is there any individual possibility of interpreting variation and deviation and inclination and amplitude. This system shows e.g. wrong slope and is not suitable for ships or aviation as a whole and therefore for navigation. According to the block diagram of Figure 2 of European Patent Publication 0 120 691, nothing is disclosed which could be considered known in connection with the present invention. It is impossible to examine the state of the entire magnetic field with a single sensor. In addition, the analog system structure provides poor accuracy compared to the digital system structure with improved accuracy. Again, local deviation, deviation, inclination, amplitude change, and administration are not possible at all.

The present invention relates to a method for determining the angular position of a measuring system according to claim 1 and to a digitally and / or analogue, fully electronic compass according to claim 3. The dependent claims set out some embodiments of the invention.

Surprisingly, it has now been found, which has not been automatically assumed, that conventional use of a magnetic needle can be replaced by at least one magnetic field member 25, resulting in more accurate direction determination, allowing signals from the magnetic field sensor to be processed more accurately.

The invention relates to a digitally and / or electronically indicating, fully electronic compass with at least one magnetic field sensor connected to a subsequent electronic circuit, the magnetic field sensor operating on the principle of Hall effect, field plate, Wheatstone bridge aperiodicity or resistance change, while the circuit consists of at least one operating amplifier, voltage stabilization, temperature compensation and an analog-to-digital converter which amplifies the change in value of the 35 magnetic field sensors and converts them into digital and / or analog signals of a certain magnitude and in turn digitally displays them 4 8 8 2 G 5 and / or optically and / or acoustically.

To illustrate the invention, it will be explained in more detail with the aid of drawings and application examples. In the drawing 5 fig. 1 is a schematic plan view of an electronic compass, FIG. Fig. 2 shows a cross-sectional view along the line A-A in Fig. 1, greatly enlarged; 3 shows a block diagram of an electronic compass, 10 fig. 4 shows a block diagram of a compass with electromotive tracking and a digital display, FIG. 5 shows a block diagram of a fully electronic, inclination-independent compass, FIG. 6 is a schematic plan view of a clock pointer plate 15 with a compass, not shown herein, mounted; 7a is a diagram of an electronic compass with quasi-analogue indication, automatic inclination compensation and acoustic course indication, FIG. 7b is a diagram of an electronic compass with quasi-analogue indication, automatic inclination compensation and acoustic course indication, FIG. 8 shows an automatic shut-off intended to be mounted on a compass in a watch.

25 Application example 1

According to Figures 1 and 2, the compass consists of an inner housing 2 and an outer housing 1. The inner housing 2 has a cardan bearing 3 to which at least one magnetic field sensor 4 is attached. The inner housing 2 is filled with damping fluid 5 and is mounted in its horizontal plane 190 ° clockwise and 190 ° counterclockwise so that the magnetic field sensor 4 can be adjusted by means of a plate 6 mounted, rotatable and graduated in the outer housing 1, which is connected via a coupling device 7 to the inner housing 2 and adjustable 35 to an arbitrary degree of 0 to 360 °.

Numeral 8 shows an operational amplifier according to Fig. 3, which consists of an integrated circuit and which amplifies the signals transmitted from the magnetic field sensor 4 and converts them to voltage values of at least 0 to 360 mV. An analog-to-digital converter 9 is then connected, which makes these voltage values visible on the LCD or LED display 10 5 on the outer housing 1 side of the compass as a three-digit degree display. The signals can be pulsed to and from the sensor.

The outer housing 1 has a switch 12 for switching from incorrect to right indication. Depending on the choice, then, in addition to the three-month number 11, as shown in Fig. 1, an alphanumeric indication M 13 or T 14 appears, where M means an incorrect indication and T means a correct indication. A control 15 is further placed in the outer housing 1 to adjust the deviation, whereby its reading can be read by pressing the button 16 on the display 10.

15 In order to display a certain point in the terrain, the compass is held exclusively in the direction of the point to be displayed, whereby a degree number, i.e. a direction angle that can only be read.

If it is necessary to select the direction angle, then the plate 6 is rotated 20 until its degree division is above the marking line 17 by the desired degree number. The compass user then rotates with the compass until LED 18 illuminates. The preselected course has been reached. If, on the other hand, the LED 18 goes out, then this means that there is a pointer to the pre-selected course. However, the device can also be designed in such a way that the ignition of the diode 18 means that it has deviated from the preselected course.

After the operational amplifier 8, a comparator 19 is further connected, which consists of an integrated circuit and which, when 30 reaches a certain voltage value of e.g. 0 mV, causes the LED 18 to light up and thus indicates that the preselected course has been reached.

The entire electronics are supplied via at least one voltage stabilizer 20 by means of a battery 21 and / or solar cells 35 or also a battery.

Application example 2

The electronic compass according to Fig. 4 consists of at least one magnetic field sensor 4, the signal of which is fed to the operational amplifier 8. A minimum-maximum detector 22 is then connected, the highest or lower value of which is fed to the difference amplifier 23. The signal of the difference amplifier 5 23 controls the electric motor drive. 24, on the shaft 25 of which a code disc 26 and a compass rose 27 are placed. The sensor 4 is connected to the shaft 25 in such a way that it rotates with it. The interpretation unit 28 outputs the coded signals to the electronics unit 29, which performs the necessary conversion 10 and numerically indicates the direction angle on the display 10.

If the compass is rotated, a differential voltage is present in the amplifier 8, which in turn forces the electric motor drive 24 to be monitored until the minimum or maximum value is reached and thus no further differential signal is present. Thus, the compass rose 27 has rotated the compass rotation angle and indicates a new direction angle. At the same time, the code disc 26 has rotated by the same angle, whereby the signals have been read and processed, whereby the direction angle is indicated in digital form in the pointer 10.

20 Application example 3

The fully electronic, inclination-independent compass of Figure 5 consists essentially of magnetic field sensors 57 fed through block 58 at a constant current. Their output signals are amplified by operational amplifiers, prefiltered, fed through a multiplexer and an analog-to-digital converter 52 to a microprocessor 44 and to inclination sensors 56, the signals of which arrive via a demodulator 54 and an analog-to-digital converter 53 to a microprocessor 44. -30 through block 55 with an AC voltage of constant amplitude. Their output signals are rectified and amplified in demodulators 54. They are then converted to digital signals via a multiplexer in an analog-to-digital converter 53 and read by a microprocessor 35 on a sorter 44. A keyboard 48, the signals of which are also fed to a microprocessor, local deviation, deviation and the program, variables, and Constants 7 88205 and the course selection can be programmed and stored in memory 43. A temperature sensor, not shown here, functions to correct errors caused by the temperature of the electronics.

For communication with the user 5, the system is provided with a graphical display 51, a control electronics 50 and a keyboard 48. The keyboard is interrogated by the query electronics 47.

These signals are then compared in microprocessor 44, processed and displayed in an arbitrary form per 10 keyboard commands with the desired result, such as correct indicating rate, incorrect indicating rate, course selection, slope, declination or deviation table on the graphical display 51 via the control electronics 50.

To print the measurement results, the system is equipped with 15 serial interfaces 49 which can send and receive data in accordance with the RS 232 C / V 24 standard. To control the program flow and take the time into account, the system is provided with a time IC and a timer 46. The entire peripheral is controlled by a microprocessor 44 via an address decoder 45.

20 The program, variables and constants are stored in memory 43.

This is equipped with EPROMs, RAMs and EEPROMs.

The program consists of a real-time kernel with controllers for the various peripherals and an interpretation program for indicating the course according to the following flow chart: 8 88205

Flow chart Ί_ 5

Reading sensor voltages

.....'..... I

Digital filtering 10 and probability test l .....'........ |

Koordinaattioikausu

15 I

Course calculation 20 Correction of deviation and davitation values

Result Printing 25 --- 9 88203 Application Example 4

Figure 6 of the compass electronics is integrated at the electronics and arranged such that the maximum sensor ulotulosignaali corresponds to the clock north-5-direction 33. If the clock is rotated pöhjoissuunntaan, the LCD screen, or a two-color display 34 of the column 35 is guided in the form of an arrow or the radially accordance with the sensor signal strength in accordance with the circle and made visible in this way. If the number 10 of the guided beams 35 no longer increases when rotated, then the north direction 33 is reached. All the main air directions can then be read immediately in the adjusting ring 36. This operation makes it possible to keep the clock obliquely in navigation. Knob 37 can be used to switch the compass on or off.

An adjusting ring 36 with a graduation can be rotatably mounted and connected to a compass sensor so that when the adjusting ring 36 is rotated, the sensor also rotates by the same angle. Thus, any arbitrary course can be preselected. The adjusting ring 36 is rotated until the desired course 20 is at the course mark 38. Thus, the preselected course is reached when the number of visible bars 35 in navigation no longer increases. Instead of or in addition to the bar display, a numerical display of the respective direction angle can take place.

The magnetic pulses of the clock can be interpreted according to the connection according to Fig. 8 so that they can no longer interfere with the correct compass indication.

It has been found that when a dynamic signal applied to a sensor, e.g. in the form of a second and / or third magnetic field, for a short time or alternately, the magnetization or response of the sensor output signal thus obtained or the time required to take the original position is a measure of the sensor position Earth's magnetic field.

35 The dynamic signal can be controlled via windings, or it can be fed directly to the sensor as a voltage change.

Using inclination sensors, the directional angle measurement 10 88205 is independent of both position and inclination. In order to also be able to measure independently of the acceleration, the magnetic field sensors are automatically switched from the specified rotational speed to measure the slope. Due to the identification of different and / or similar signal changes in the magnetic field member 5 and by comparison immediately with the holding value curve stored above, the slope change in the state can be calculated so that no false course indication is formed. This also makes it possible to calculate the change in acceleration. The signals are processed and calculated in a microprocessor.

As shown in Figures 7a and 7b of the analog compass, a magnetic signal proportional to the magnetic field is received and amplified by a difference amplifier 59. The output signal of this amplifier 15 is coupled to the circuit output of Figure 8 In the vicinity of the magnetic field sensor 20 according to 3 and 4. If, on the other hand, no such interference occurs, then the coupling part according to Fig. 8 may be omitted. The combined signal is then further amplified in amplifier 60, simultaneously attenuating the high frequency portions of the input signal while performing rough offset compensation. Further confirmation can also be set here. The corrected output signal then arrives at a non-linear amplifier 61, which emphasizes the maximum of the measurement signal that would otherwise run very low. Also in this amplifier, the measurement signal is filtered 30 more times. In addition, the offset 61 in the automatic control loop is fine-tuned.

After these pretreatments, the measurement signal has an amplitude of +4 V in the north and an amplitude of 0 V at about 30 degrees and 330 degrees. For the desired assignment, this signal 35 must be inverted once more. This occurs in amplifier 62 so that there is a minimum in the north. This signal is then fed to the display controller IC 63 and indicated as a clear pattern on the display 64.

The course of each measurement takes place in three steps: Step 1: automatic fine-tuning of the displacement, in which case the position of the magnetic field sensor 4 is arbitrary with respect to the north.

At the beginning of the measurement, the counter 66 is reset. Thus, the output voltage of the digital-to-analog converter becomes minimal, and the input voltage of the comparator 65 is also forced to a minimum so that the clock signal obtained from the display controller IC 63 is released for the counter 66. Incrementing the calculator 66 increases the output voltage of the digital-to-analog converter 67. When the displacement is almost equalized, the output voltage of the comparator 65 begins to increase. If this voltage has risen to approximately 200 mV, then clock 15 of the calculator 66 is closed so that this state is maintained.

Phase 2: The first exploration in the north.

If the magnetic field sensor 4 approaches the north direction, then the input signal of the comparator 65 decreases again, so that the offset compensation is activated again and the voltage 20 reaches 200 mV again. This event is repeated until the magnetic field sensor 4 has reached the north direction.

Steps 1 and 2 can also occur simultaneously.

Step 3: The actual measurement.

25 If the magnetic field sensor 4 is moved back and forth around the north direction, then each time in the north 200 mV is transferred again to the display controller IC 63 and the farther away from the north, the higher the voltage becomes: V until a clear indication appears on the display.

30 A negative supply voltage is also required to use the connection. This is obtained from the positive supply voltage through the voltage inverter 68. In addition, the connection is supplemented by an acoustic north indication. ; la. This consists of both flip-flops 69 and 70, a piezo sound device 71 and associated gates. Flip-flop 70 acts to close the audio device after switching on until: · the displacement is smoothed, while flip-flop 69 triggers the sound when the measuring voltage i2 8 8 2 G j is at a minimum.

The advantages of the compass according to the invention can be seen in the fact that, as in known gyrocompass systems, there is no increasing error here and it does not have to be reset according to a conventional magnetic compass before or during the journey. In contrast to known compasses, there is no pre- or post-indication when rotated. Deviations caused by declination and deviation can be corrected automatically. Also, for the first time 10, a right-pointing course indication, a slope, course and acceleration indication is possible without the use of a gyroscope and without the need for mechanical and / or optical devices. An accelerator is also not required.

Depending on the structure, the area of application extends to land, water, air and space vehicles and as a measuring, pocket or clock compass.

Claims (5)

A method for determining the angular position of a multiaxial measuring system, in particular a vehicle-connected measuring system, in space, the angular position of the measuring system being expressed in relation to a gravity vector and a magnetic field vector, characterized by monitoring the rotational angular velocity of the measuring system with respect to at least one rotating axis , until the angular position detection with respect to the gravity vector 10, taking into account the effect of centrifugal force, is still sufficiently accurate, only the angular position detection of the measuring system with respect to the magnetic field vector is enabled, and the angular position of the measuring system in space is determined. further reversal of the measuring system with respect to the magnetic field vector. Method according to Claim 1, characterized in that the azimuth difference between one axis of the measuring system, which is arranged in the direction of the length or instantaneous movement of the vehicle, and the magnetic meridian is determined from the determined angular position of the measuring system in space. A digitally and / or analogue, fully electronic compass for determining the angular position of a multiaxial measuring system, in particular connected to a vehicle 25, in space, the angular position of the measuring system being expressed relative to a gravity vector and a magnetic field vector, characterized in that the compass comprises a measuring system ), 30 wherein the rate of rotation is monitored with respect to at least one axis of rotation and, if the predetermined value of the rate of rotation is exceeded until the indication of the angle position with respect to the gravity vector, taking into account the effect of centrifugal force, is still sufficiently accurate. 35 only the detection of the angular position of the measuring system with respect to the magnetic field vector, and in connection therewith an apparatus for determining the angular position of the measuring system in space, wherein the angular position in space is determined by detecting further rotation of the measuring system with respect to the magnetic field vector. 882C.J A compass according to claim 3, characterized in that the compass further comprises an apparatus for determining the azimuth difference from the angular position of the measuring system in space between one axis of the measuring system arranged in the longitudinal or instantaneous direction of movement of the vehicle and the magnetic meridian. ! 5 8 8 2 G j