DE4038284A1 - Measuring position and direction of motion of part - moving in translation and/or rotation using single sensor and direction encoded signals, esp. for vehicle electric windows and roof - Google Patents

Abstract

A method of measuring the position and direction of a part involves evaluating pulses produced by the drive system for the system contg. the part. A defined number of counter pulses is generated in a rotation coded sequence per complete revolution of the rotary drive or counter pulses are generated in rotation direction encoded form from a defined number of direction encoded analogue signals. The encoded pulses are fed into a computer in which they are added or substracted according to the encoded direction information. USE/ADVANTAGE - Esp. for electric windows and sun roof of a motor vehicle. Enable high resolution to be achieved using only one sensor.

Description

The invention relates to a method for determining the position and direction of movement of a transla Toric and / or rotationally moving part of a Units according to the preamble of claim 1 and Devices for performing the method.  

It is known to be translatory and / or rotary moving parts of a operated by a rotary drive Aggregates between two way end points move the parts between the endpoints one any number of movements in opposite Can perform directions of movement. The parts can be added as often as required between the way end points will hold. An identification of the position and the Direction of movement of these parts between the end points is particularly important in the area of endpoints tung.

If the construction and / or use of this Share direct monitoring of the path and the Do not allow direction of movement, it is required appropriate information using the Determine transmission parameters.

A rotary drive of an assembly stands with it parts moved in translation or rotation in a clear mechanical relationship that it allowed, from the difference in numbers of opposing Revolutions of a rotary drive the distance covered and thus determine the end position of these parts.

Such a technique is particularly useful for building elements important that close the openings. At the Closure of an opening is by a closure element it is often necessary for security reasons that before Reaching the closed position of the drive when Resistance stopped can be. This security precaution is in particular This is necessary if there is a risk that the Closing the opening people get hurt can.  

One example is the operation of windows and Sunroofs in motor vehicles pointed out. window and sunroofs are translational moving parts one unit actuated by a rotary drive. Windows and sunroofs can be between the public Opening and locking position when operating a Vehicle can be moved back and forth as often as required. A The moment of danger occurs shortly before the closed position of the Window or the sunroof. Body parts of a People can get trapped and it doesn't matter essential to eliminate injuries that if resistance occurs, the drive is abge is switched. However, this security precaution is only within a predetermined movement stroke required and in order to make this movement stroke clear Determining the way is to determine the position of the Window or the sunroof required.

Methods are already known in which the corresponding information from the rotary drive be tested. The rotary actuator is used generated by two sensors. The one sensor takes counting pulses, from which the number of Revolutions of the rotary drive are determined and the other sensor is used for direction of rotation deliverations.

The sensors are available with computers, for example Microcomputers in connection and the microcomputer gives appropriate control signals before switching the Rotary actuator.

This known mode of operation has the disadvantage that in the rotary actuator two sensors must be installed. In order to achieve the most accurate position possible,  a high-precision sensor system must be provided, the one rotation of the rotary drive, for example of the window regulator motor in several sub-areas divides, so that overall a complex and thus in the manufacture of expensive sensor device for implementation tion of the procedure must be provided.

The present invention is based on the object a method and devices for detecting the Position and direction of movement of a translational and / or rotationally moving part of an assembly to specify the genus mentioned at the beginning, which at high resolving power of position and movement Direction detection requires only one sensor device make derlich and thus a low manufacturing require effort.

This object is inventively by the Drawing feature of claim 1 solved.

The solution according to the invention enables both Position as well as a direction of movement detection with only one sensor, the movement proportional Gives impulses, the direction of movement information unfold and thus be processed directly can.

One turn of the rotary drive is made per full revolution correct number of counts in the direction of rotation coded Pulse trains generated. These are a calculator in particular supplied to a microcomputer and in this depending on the coded direction formation adds or subtracts. In this way can be the difference in the number of opposite rotations Rotations of the rotary actuator can be determined and thus  because of the fixed parameters of the rotary drive the position of the moving part. This information can then be used to control the Operation can be used. With a special advantage the pulse repetition frequencies of the pulse trains become Determination of the direction information with two given compared pulse repetition frequency patterns.

A simple evaluation can be done in that one-sided counts generated and their edges be counted.

It is particularly advantageous per revolution of the Rotary drive six in total, on three pulse trains distributed counting pulses of the same pulse duration generate that in a direction of rotation of the rotary drive a counting pulse in a first angular range, in a pulse sequence with a second angle of rotation range two counts and in a third angle of rotation submit a pulse train with three counts same pulse durations between the pulse trains and same pause times in the pulse sequences and vice versa returns to a computer via a single channel.

This procedure has the great advantage that already within half a turn of the Rotary drive reverses the direction of the rotary drive can be determined so that this method with extraordinary accuracy works. If the Pause times in the pulse sequences and the pulse durations can be leveled, so with this procedure a direction coding of the pause times between the Pulses are performed. There are only two There are types of break times, namely break times between the pulse sequences and pause durations between  the counts.

The pauses between the pulse trains are longer and the pause times between the counts are smaller. This means that a certain pattern of successive long and short breaks is formed in the pulse generation.

If an operational phase is started, it is not required, the exact angular position of the turn to know instinct. If the position with an error is known to be less than half a value Rotation of the rotary drive so it is possible to Perform adjustment when referring to the procedure the now occurring impulses are synchronized.

There is a possibility of angular velocity to measure when the pause duration is the same length be measured.

During the procedure, the pause times are measured and saved. The sizes of the break times are then compared. If three pause times were recorded, then so it is possible to change the size of all three break times test and only the information whether the Pause times are large or small is saved.

If one designates the long pause times between the Pulse sequences with L and the pause times between the individual pulses in these pulse sequences with S, see above the saved pause duration information with compared the following two patterns:

LSLSSLLSLSSL (forward)
LSSLSLLSSLSL (backward)

Only one of these patterns is applicable and therefore, the position can only be used three pause times can be determined in this pattern.

When the synchronization sequence is over, the Position set to the synchronized position by the pattern of different lengths Pause times is determined. The position will then determined until the rotary drive is switched off.

An advantageous development of the invention The method is characterized in that the wavy speed of the motor current of an existing electric motor detected and fed to the computer.

By detecting the ripple of the motor current of an existing electric motor, which by the commu between the different motor windings is caused, the motion measurement can be very fine be divided so that a highly accurate resolution is possible.

It is within the scope of the invention a direction of rotation co dated sequence of counts with the sequence of a Count pulse with the pulse duration T and after one Pause time T is a counting pulse with the pulse duration n × T with n <= 2 and subsequent pulse duration n × T generate and vice versa. At this encoded pulse this is followed by adding and subtracting according to the directional information generated by the pulse is given.

The counts are particularly advantageous by means of of the Hall effect and one with the rotary drive firmly connected coding disk generated.  

It is within the scope of the invention, per revolution of the Rotary actuator depending on its polarity of the direction of rotation of the rotary drive once from positive to negative values or vice versa to form an alternating analog voltage from its positive or negative section generates a count pulse and Direction-coded at the zero crossing of the analog voltage becomes.

In this process, an analog is first used signal determines which direction is coded and this analog signal is then converted into a counting pulse converted, the shape of which is direction-coded. With The analog becomes particularly advantageous at the zero crossing voltage the pulse roof of the count pulse depending on Direction of rotation of the rotary drive on the front or Trailing edge of the count pulse deformed.

With this method, the analog voltage is above two parallel comparators in which the Rich tion information is determined, a computer fed.

It is advantageous to generate the analog voltage the magnetization direction of a Hall element once per revolution of the rotary drive to change or disrupt its magnetic flux once.

In a device for performing the fiction The method according to the invention is one with the rotary drive firmly connected disc provided on which a ring from a predetermined number arranged in series Brands is trained. Next to the disc is in Area of the ring responsive to these brands Hall element arranged, the output with a  Computer is connected.

Particularly advantageous are the peripheral edge of the disc six brands that have the same circumferential angle sen, trained to follow a brand in connect two marks at a circumferential angular distance, which from each other a predetermined circumferential angle have and to this at a circumferential angular distance another three brands, which also have an extensive win distance from each other. The circumferential angle distances between the brands within the brand sequences equal to their circumferential angle.

A particularly advantageous and simple execution shape arises when the circumferential angle of the marks and the circumferential angular distance between the marks is 15 ° each and the circumferential angle distance 75 ° between the brand sequences.

It is within the scope of the invention, the device which first generates an analog signal shape that one rotatably on the rotary drive arranged disc in the direction of a diameter is magnetically polarized and in the range of one Sector of circles, the bisector of its zen angle perpendicular to the magnetic polarization runs, has a demagnetized section. A Hall element is arranged next to this disc, its output via two Kompara connected in parallel is connected to a computer. At a The disc is rotated in the Hall element by the Reverse magnetic polarization a positive and generates a negative voltage half-wave that are separated from each other by a zero section which the magnetized section causes.  

In another embodiment of a device, at which an analog voltage is generated is a Hall element, the output of which has two comparators connected to a computer, in a magnetic Arranged in a circle in which the magnetic flux of a motor worm is closed.

In this embodiment, the Hall element is located on the one hand on a pole of a permanent or electric magnets and on the other hand on a pole of a soft magnet magnetic yokes, which have a beveled Has end section. The motor worm has one Section on the space between the other magnetic pole and the tapered end portion of the soft magnetic yoke. Through the The helix turns into one with one revolution magnetic polarity reversal and the abge slanted gap between the soft magnetic yoke and the worm creates a sawtooth-like tension course.

Embodiments of the invention are intended to Explained with reference to the figures of the drawing will.

Show it:

Fig. 1 is a schematic view of a sensor,

Fig. 2 is a schematic view of a coded disc,

Fig. 3 is a schematic view richtungsorien-oriented pulse trains, which are generated by the embodiment shown in Figs. 1 and 2 Sensorein direction,

Fig. 4 is a schematic view of a circuit for implementing the method,

Fig. 5 is a schematic view of a Codierschei be for generating an analog signal,

Fig. 6 are schematic views of the signals obtained with the embodiment shown in FIG. 5 device,

Fig. 7 is a schematic diagram,

Fig. 8 is a schematic view of a sensor training for performing the method and

Fig. 9 is a schematic view of the signals that can be obtained with the arrangement shown in Fig. 8.

As an example, assume that the invention Method for a window regulator of a motor vehicle is applied.

In Fig. 1, an electric motor is shown schematically at 7 , which actuates a drive of a window lifter designated 6 . A coded disk 13 , which is tapped by a Hall element 3 , is connected in a rotationally fixed manner to this drive 6 . Instead of a Hall element, any other optoelectronic, capacitive, inductive or ohmic scanning element can be used.

A top view of the disk 13 is shown in FIG. 2.

As shown in FIG. 2, the disk 13 has three groups of marks 14 on the edge, to which the Hall element 3 responds. A single mark 14 is shown which includes a circumferential angle T. In the direction of the clockwise rotation are at an angular distance L from this individual mark two successive marks 14 , which also have a circumferential angle T and which are arranged at an angular distance S from one another.

Further in the clockwise direction, a group of three marks 14 follows at a circumferential angular distance L and each of these marks has a circumferential angle width T. In this group, the marks in turn have an angular distance S from one another. This group in turn has an angular distance L in the clockwise direction from the individual mark 14 mentioned at the beginning.

In this embodiment, the circumferential angles T of all marks 14 are the same, furthermore the angular distances L and the angular distances S are equal to one another. In particular, the angular distances S are equal to the circumferential angle widths T.

In the illustrated embodiment, the Circumferential angular distances L = 75 °, the circumferential angular distances S = 15 ° and the circumferential angle widths T also 15 °.

The plan view of the disc in Fig. 2 can be seen that when rotating this disc counterclockwise sets the Hall element 3 shown in Fig. 1 per revolution, the rotation direction-coded pulse trains 2 shown in Fig. 3 generates.

As FIG. 4 shows, the direction of rotation coded pulse sequences shown in FIG. 3 are fed via channel 4 to a computer 5, for example a microcomputer. The number of revolutions of the disk 13 and thus of the rotary drive 6 can be determined by counting the edges of the counting pulses 1 shown in FIG. 3. The direction of rotation information, which determines whether addition or subtraction is carried out, is determined from the shape of the pulse trains.

As FIGS. 2 and 3 show, the pause durations between the counting pulses in the pulse sequences 2 are suitable for the direction coding. These pauses are determined by the angles L and S, which are shown in FIG. 2 and recorded as pause times in FIG. 3.

If the disk 13 rotates counterclockwise in the illustration in FIG. 2, there is a pause duration or an angle pattern with the following consequence:

L S L S S L L S L S S L (one direction of rotation)

With an opposite rotation results following pattern:

L S S L S L L S S L S L (different direction of rotation)

These two patterns, which are only possible and which uniquely determine the direction of rotation, are stored in the computer 5 and the signals fed from the Hall element 3 via the line 4 to the computer 5 , which are shown in FIG. 3, therefore enable counting the rotation, for example by counting the edges of the pulses 1 and at the same time determining the direction of rotation by comparing the pattern of the pause times with the two possible patterns stored in the computer 5 . Depending on the result of this comparison, the counted revolutions are added or subtracted, so that a difference is formed which indicates the position.

It can be seen that the direction of rotation can be determined within half a revolution of the disk 13 , since only three pause signals are required, which are in an angular range of 120 °.

In addition to digital coding, coding by means of an analog voltage is possible, as is shown schematically in FIG. 5.

Essentially the same basic construction as in Fig. 1 is used. The disk 13 shown in Fig. 1 is replaced by the disk 18 shown in Fig. 5 Darge. This disk 18 has a magnetization axis running in the direction of the diameter 19 shown.

A demagnetized section 20 is formed in this disk within a circular sector whose bisector of the centering angle intersects the magnetic polarization axis NS at a right angle.

When the disk 18 with the rotary drive 6 moves past the Hall element 3 shown in FIG. 1, the analog voltage shown at the top in FIG. 6 is generated depending on the direction of rotation. When the disc is rotated, for example, a positive analog voltage is initially generated and during the passage of the demagnetized section 20 there is a zero period, ie a zero crossing, which is followed by a negative voltage section.

It can be seen that the analog voltage shown in FIG. 6 above in its course depends on the direction of rotation of the disk 18 . As shown in FIG. 7, this analog voltage is supplied via the line to two comparators 12 and 13 connected in parallel, and a comparison is carried out in these, which leads to the formation of the pulse shown in FIG. 6, which has a directional coding in its form.

The directional pulses 8 shown in FIG. 6 below have a roof that is formed on the front flank for direction coding. If, for example, the direction coding of the roof of the counting pulse 8 shown in FIG. 6 means "add", then it can be clearly seen that, when the disk 18 rotates in the direction of rotation, a pulse that is used as a counting pulse is generated, the direction coding of which is on the opposite edge in the illustration in Fig. 6, so that in each case a count is formed with a directionally-doped roof.

In the embodiment shown in FIG. 8, a Hall element 3 , the output of which is connected as shown in FIG. 7, is arranged in a magnetic circuit 21 . The Hall element 3 is mounted on a circuit board 28 and the magnetic circuit comprises a permanent magnet 27 or an electromagnet which has the polarization SN shown. The magnetic circuit 21 also has a soft magnetic yoke 23 made, for example, of iron. A pole 25 of this yoke bears against the Hall element 3 .

This soft magnetic yoke 23 has a beveled end portion 24 . The gap between the magnet 27 and the beveled end 24 is bridged by a section 26 of a motor worm 22 so that it closes the magnetic flux in this magnetic circuit. If the motor worm rotates in one direction, because of the coupling of the magnetic flux of the worm 22 to the bevel 24 of the yoke 23, the sawtooth-shaped voltage U shown in FIG. 9 is generated, which, as shown in FIG. 7, is fed to the two comparators and these After a comparison, the direction-coded pulses 8 lead to the computer 5 , which are shown in FIG. 9 below.

The instantaneous position is formed from the number of revolutions determined by means of the pulses 8 and the direction of magnetization, ie the disturbance of the magnetic flux.

Claims (20)

1. A method for determining the position and the direction of movement of a translationally and / or rotationally moving part of a drive actuated by a rotary drive unit are evaluated in the pulses generated by the rotary drive, in particular for windows and sunroofs in motor vehicles, characterized in that
from the rotary drive ( 6 ) per full revolution ( 2 T) a predetermined number of counts ( 1 ) in direction-coded pulse trains ( 2 ) or
from a predetermined number of rotation-coding analog signals ( 8 a) counts ( 8 ) are generated with a direction-coded form and
the direction-coded or shaped counting pulses ( 1,8 ) are fed to a computer ( 5 ) and are added or subtracted depending on the coded directional information. 2. The method according to claim 1, characterized in that the pulse repetition frequencies of the pulse trains ( 2 ) for determining the directional information are compared with two pre-given pulse repetition frequency patterns. 3. The method according to claim 1 or 2, characterized in that one-sided counting pulses ( 1 ) are generated and their edges are counted. 4. The method according to at least one of claims 1-3, characterized in that per revolution ( 2 II) of the rotary drive ( 6 ) a total of six, distributed over three pulse trains ( 2 ) Zählim pulse ( 1 ) of the same pulse duration (T) are generated, that same one direction of rotation of the rotary drive in a first rotary angle range of a count pulse (1), in a second rotary angle range, a pulse sequence (2) with two counts (1) and in a third rotational angle range, a pulse sequence (2) with three counts (1) with Pauses (L) between the pulse trains ( 2 ) and the same breaks last (S) in the pulse trains and vice versa are fed to the computer ( 5 ). 5. The method according to claim 4, characterized in that the pause times (S) in the pulse trains ( 2 ) and the pulse durations (T) are the same. 6. The method according to claim 4 or 5 characterized in that the direction of rotation information from the sequence of Break times (L), the pulse sequences and the breaks duration (S) of the counting pulses is derived. 7. The method according to any one of claims 1-3 characterized in that a direction-coded sequence of counts with the sequence a count pulse with the pulse duration T and after a pause T a counting pulse with the Pulse duration n × T with n = 2 and later Pause time n × T is generated and vice versa. 8. The method according to at least one of claims 1-7, characterized in that the counting pulses ( 1 ) are generated by means of the Hall effect and a coded disc ( 13 ) connected in a rotationally fixed manner to the rotary drive ( 6 ). 9. The method according to at least one of claims 1-8 in which the rotary drive has an electric motor, characterized in that the synchronization signal for determining the time of a reversal of the direction of rotation of the rotary drive ( 6 ) detects the ripple of the motor current of the electric motor ( 7 ) and the Computer ( 5 ) is fed. 10. The method according to claim 1, characterized in that per revolution ( 2 II) of the rotary drive ( 6 ) one, its polarity depending on the direction of rotation of the rotary drive ( 6 ) once from positive to negative values or vice versa changing analog voltage (U) is formed , from whose positive or negative section a counting pulse ( 8 ) is generated and direction-coded when the analog voltage crosses zero. 11. The method according to claim 10, characterized in that at the zero crossing of the analog voltage (U) the pulse roof of the counting pulse ( 8 ) depending on the direction of rotation of the rotary drive on the front or rear flank of the counting pulse ( 8 ) is deformed. 12. The method according to claim 10 or 11, characterized in that the analog voltage (U) via two parallel comparators ( 11 , 12 ) is fed to a computer ( 5 ). 13. The method according to at least one of claims 10-12, characterized in that for generating the analog voltage (u) the direction of magnetization direction of a Hall element ( 3 ) once per revolution ( 2 II) of the expansion drive ( 6 ) or its magnetic flux is disturbed. 14. A device for performing the method according to at least one of claims 1-9, characterized in that a rotatably connected to the rotary drive ( 6 ) disc ( 13 ) on which a ring formed from a predetermined number of marks arranged in sequence ( 14 ) and a Hall element arranged next to the disk ( 13 ) in the region of the ring and responding to the marks ( 14 ), the output of which is connected to a computer ( 5 ). 15. The method according to claim 14, characterized in that on the peripheral edge of the disc ( 14 ) six marks ( 14 ) having the same circumferential angle T are formed such that two marks (L) at a mark ( 14 ) in the circumferential angle distance (L) 14 ) which have a circumferential angular distance (S) from one another and these three marks ( 14 ) in the circumferential angular distance L, which are arranged at a circumferential angular distance (S) from one another. 16. The apparatus according to claim 14, characterized in that the circumferential angle distances (S) between the marks ( 14 ) is equal to their circumferential angle (T). 17. The apparatus according to claim 15 or 16, characterized in that the circumferential angle T of the marks ( 14 ) and the circumferential angular distance between the marks ( 14 ) in each case 15 ° () and the circumferential angular distance between the mark sequences are each 75 °. 18. Device for carrying out the method according to at least one of claims 10-13, characterized by a disc ( 18 ) which is connected in a rotationally fixed manner to the rotary drive ( 6 ) and which is magnetically polarized (NS) in the direction of a pressure gauge ( 19 ), and in the region of the circular sector, the bisector of its centering angle perpendicular to magnetic polarization ( 19 , NS), has a demagnetized section ( 20 ), and a Hall element ( 3 ) arranged next to the disk ( 18 ), the output of which is connected via two comparators ( 11 , 12 ) is connected to a computer ( 5 ). 19. Device for performing the method according to at least one of claims 10-13, wherein the rotary drive has a motor worm, characterized in that a Hall element ( 3 ), the output of which is connected to a computer ( 5 ) via two comparators ( 11 , 12 ) is arranged in a magnetic circuit ( 21 ) in which the magnetic flux from the motor worm ( 22 ) is closed. 20. The apparatus according to claim 19, characterized in that the Hall element ( 3 ) on the one hand against a pole (N, S) of a permanent or electromagnet ( 27 ) and on the other hand against a pole ( 25 ) of a soft magnetic yoke ( 23 ), which has a chamfered end portion ( 24 ), and that the motor worm ( 22 ) has a portion ( 26 ) which the space between the other magnetic pole (S, N) and the chamfered end portion ( 24 ) of the soft magnetic yoke ( 23 ) bridged.