DE102019124855B3 - System and method for optical touchdown detection with throat play compensation for small placement forces - Google Patents

Abstract

The invention relates to a fitting system (100) for fitting objects with fitting elements. The assembly system (100) comprises a drive body (101) with a connecting element (107), a drive (103), a first sensor (115), at least one second sensor (117) and a control device (123). The connection element (107) is configured to transmit a drive force to be provided by the drive (103) to a mating connection element (111) on a pipette (109). The drive (103) is configured to move the drive body (101). The first sensor (115) is configured to determine first measured values of a movement of a movable element (119) of the pipette (109) relative to a base body (121) of the pipette (109). The at least one second sensor (117) is configured to determine second measured values of a movement of the base body (121) relative to the drive body (101), and the control device (123) is configured to combine the first measured values with the second measured values in a mathematical Adjust the adjustment process in order to determine a corrected distance of a movement of the movable element (119) of the pipette (109) and to use the corrected distance to detect a placement of a fitting element to be arranged on the movable element (119) of the pipette (109) on an object. The presented invention also relates to an assembly method.

Description

The presented invention relates to a mounting system and a mounting method.

To equip surfaces, such as, for example, a circuit board, with assembly elements, such as, for example, a light-emitting diode, assembly systems are generally used. A component is picked up by a pipette and placed on a surface. Correspondingly, the pipette has to be moved during a placement process in order to enable contact between the fitting element arranged on the pipette and the surface.

To move a pipette, a placement system is equipped with a drive which transmits its driving force via a connecting element to a counter-connecting element of the pipette. Since a connection between the connecting element and the counter-connecting element is set up with a movement tolerance or “play”, a movement of the pipette by the drive is subject to a variance caused by the movement tolerance. This leads to the fact that a large movement is necessary to detect the placement of the mounting element on the surface, which movement can be distinguished from the movement tolerance by a sensor and accordingly recognized as a placement movement. Such a large movement can only be achieved by means of a correspondingly large spring element, which however requires a large driving force or loading force in order to be moved.

The US 6 160 620 A describes an optical sensor for a pick and place machine.

The WO 2011/061670 A1 describes a device for picking up and arranging electrical components of a circuit board by means of a suction device.

Neither that US 6 160 620 A nor the WO 2011/061670 A1 however, describe a system and a method in which a first sensor for determining first measured values of a movement of a movable element of a pipette relative to a base body of the pipette and at least one second sensor for determining second measured values for a movement of the base body relative to a drive body is used to determine a corrected distance of a movement of a movable element of the pipette and to use the corrected distance to detect a placement of a fitting element to be arranged on the movable element of the pipette on an object.

Against this background, it is an object of the present invention to enable an improved assembly procedure. In particular, it is an object of the presented invention to provide a possibility for equipping a surface with an equipping element using a minimal equipping force.

The above-mentioned object is achieved by the subject matter of the respective independent patent claims.

In the context of the presented invention, an assembly system and an assembly method with the features of the respective independent patent claims are presented. Further features and details of the invention emerge from the respective subclaims, the description and the drawings. Features and details that are described in connection with the assembly system according to the invention naturally also apply in connection with the assembly method according to the invention and vice versa, so that with regard to the disclosure, reference is or can always be made to the individual aspects of the invention.

In a first aspect, the presented invention relates to a placement system. The assembly system comprises a drive body with a connecting element, a drive, a first sensor, at least one second sensor and a control device. The connection element is configured to transmit a drive force to be provided by the drive to a mating connection element on a pipette. The drive is configured to move the drive body. The first sensor is configured to determine first measured values of a movement of a movable element of the pipette relative to a base body of the pipette. The at least one second sensor is configured to determine second measured values of a movement of the base body relative to the drive body. The control device is configured to compare the first measured values with the second measured values in a mathematical comparison process in order to determine a corrected distance of a movement of the movable element of the pipette and, based on the corrected distance, to place a fitting element to be arranged on the movable element of the pipette on a Object to be detected.

In the context of the present invention, the term “detect” is to be understood as a process in which a state, in particular a placement of a fitting element to be arranged on a movable element of a pipette on an object, is detected or recognized.

In the context of the presented invention, a control device is to be understood as a computing unit, such as, for example, a processor for regulating or controlling a technical component, such as, for example, respective components of the presented assembly system.

The assembly system presented includes a drive body, which can be an elongated rigid body, for example. The drive body can be moved by the drive provided according to the invention.

The drive provided according to the invention is configured to move the drive body in particular in the direction of movement of a tip or a movable element of a respective pipette. For this purpose, the drive can comprise a lifting element, such as a pneumatic, electrical, magnetic or hydraulic element.

In order to transmit a drive force provided by the drive provided according to the invention to a pipette and, as a result, to move a fitting element arranged on the pipette and finally to arrange it on a surface, the drive body comprises a connecting element, such as a hook or a receptacle, such as for example an eyelet or a recess. The connecting element is configured to interact with a counter-connecting element on the pipette or to connect to the counter-connecting element in a form-fitting or force-fitting manner. For this purpose, the connecting element can engage in the counter-connecting element or the counter-connecting element can engage in the connecting element in order to provide a form-fitting or non-positive connection of the connecting element and the counter-connecting element.

Since a connection between the connecting element and the counter-connecting element always has a movement tolerance, ie a distance between the connecting element and the counter-connecting element or a "play", the drive body will first reduce the distance between the connecting element and the counter-connecting element in a movement mediated by the drive. until the connecting element and the counter-connecting element touch and the force provided by the drive is transmitted from the connecting element to the counter-connecting element to a base body of the pipette and finally to a movable element of the pipette.

During the movement in the direction of the printed circuit board, relative movements can take place between the connecting element and the mating connecting element. These relative movements are caused by different mass and disruptive forces on the circuit board and connection element. It follows from this that the position of the mating connecting element to the connecting element can be changed within a "play". At the end of the movement, the moving element of the pipette hits the circuit board. The relative distance between the connecting element and the counter-connecting element existing at this point in time is a "residual play" within the limits of the "play", in which a form fit between the two elements occurs.

As soon as a fitting element arranged on the movable element of the pipette, such as a pipette tip, hits a fixed body such as a printed circuit board, the movable element is moved against the direction of movement of the main body of the pipette. Due to the variable distance between the connecting element and the mating connection element, the first sensor of the assembly system presented on the drive body initially moves with a movement of the drive body relative to the moving part of the pipette due to a respective “remaining play”, so that this movement of the first sensor when measuring the following movement of the movable element relative to the drive body is entered as a variance.

Correspondingly, a distance of the movement of the movable element of the pipette cannot be exactly determined by measured values determined only by means of the first sensor.

In order to detect a part of a movement of the movable element detected by the first sensor relative to the drive body and to correct the movement of the movable element detected by the first sensor accordingly, a second sensor is provided according to the invention that detects a movement of the drive body detected relative to a base body of the pipette. Correspondingly, based on measured values of the second sensor, it is possible to infer a proper movement of the first sensor, so that a corrected distance of a movement of the movable element of the pipette can be concluded independently of the proper movement of the first sensor. For this purpose, it is provided that measured values determined by means of the second sensor are mathematically compared with measured values determined by means of the first sensor in order to determine the corrected distance of the movement of the movable element relative to the drive body.

By using a corrected distance of movement of the movable element relative to the drive body, the can actually go through the movable element of the pipette can be selected to be very small, in particular as large as a movement tolerance between the connecting element and the counter-connecting element or smaller, so that a spring element of the movable element of the pipette can be selected correspondingly small or short. This means that by using a corrected distance of a movement of the movable element relative to the drive body, even the smallest movements of the movable element of the pipette can be reliably detected, so that the presented assembly system is particularly advantageous for precise or force-sensitive assembly processes, for example on particularly thin ones Foils, is suitable. In particular, by using a corrected path, a spring characteristic of the spring element can be selected to be particularly stiff, since only a minimal or corrected path has to be overcome by the spring element in order to carry out an assembly process.

It can be provided that the first sensor and / or the at least one second sensor is or are arranged on the drive body. A physical connection between the respective sensors and the drive body avoids a measurement variance caused by a movement between the drive body and the respective sensors.

It can furthermore be provided that the control device is configured to activate a release mechanism of the pipette when a placement of the fitting element to be arranged on the movable element of the pipette on the object is detected.

In order to complete a loading process and to activate a release mechanism, a placement of a loading element on an object can be recognized by, for example, evaluating a distance of a movement of the movable element of the pipette provided according to the invention. Since the path of the movement of the movable element can be determined very precisely or without a measurement tolerance caused by a movement tolerance using the assembly system presented, it is possible to activate the trigger mechanism very precisely and, as a result, to position the assembly element exactly on the object to enable.

It can be provided that the assembly system comprises a pipette with a mating connection element arranged on a base body of the pipette, and a first reflective element is arranged on a movable element of the pipette, with which the first sensor interacts during a measurement Pipette at least one second reflective element is arranged, with which the at least one second sensor interacts during a measurement.

By means of reflective elements and using optical sensors, a particularly high contrast ratio can be achieved between an area to be detected and a background. Correspondingly, by using a pipette with a large number of reflective elements which can be assigned to the respective sensors, a particularly precise measurement of a movement of the pipette can be made possible.

It can further be provided that the control device is configured to detect a touchdown of the movable element in the event that the corrected distance of the movement of the movable element of the pipette is greater than or equal to a touchdown threshold, and that the control device is further configured to do so is to determine the touchdown threshold value based on the corrected distance or to correct a predetermined touchdown threshold value based on the corrected distance.

In order to minimize a loading force which is transmitted from the movable element of the pipette provided according to the invention to a pipette to be loaded during a loading process, a dynamically ascertained set-down threshold value can be used, which is determined or corrected on the basis of the determined or corrected distance. This means that the touchdown threshold value, which can be used, for example, to trigger a triggering mechanism of the pipette, is corrected for the play to be overcome by the drive body during a respective movement. The touchdown threshold value can be a force to be transmitted when the movable element of the pipette touches a respective object to be equipped and / or a distance to be overcome before the mobile element of the pipette touches it. In particular, the touchdown threshold is reduced or adapted proportionally to the corrected route.

It can be provided that the control device is configured to subtract the second measured values from the first measured values and / or to divide the first measured values by the second measured values in the calibration process.

Through a mathematical comparison of first measured values and second measured values in a subtraction and / or a multiplication or in any other technically suitable mathematical process, the movement of the movable element can be independent of a Movement tolerance between the connecting element and mating connecting element can be determined.

1. a) Bewegen des Antriebskörpers durch den Antrieb, um eine durch den Antrieb bereitgestellte Antriebskraft durch das Verbindungselement auf ein Gegenverbindungselement einer Pipette zu übertragen,
2. b) Ermitteln von ersten Messwerten einer Bewegung eines beweglichen Elements der Pipette relativ zu einem Grundkörper der Pipette mittels des ersten Sensors,
3. c) Ermitteln von zweiten Messwerten einer Bewegung des Grundkörpers der Pipette relativ zu dem Antriebskörper mittels des mindestens einen zweiten Sensors,
4. d) Abgleichen der ersten Messwerte mit den zweiten Messwerten in einem mathematischen Abgleichprozess,
5. e) Ermitteln einer korrigierten Strecke einer Bewegung des beweglichen Elements der Pipette anhand eines Resultats des Abgleichs in Schritt d), und
6. f) Detektieren eines Aufsetzens eines an dem beweglichen Element der Pipette angeordneten Bestückungselements auf dem Objekt unter Verwendung der in Schritt e) ermittelten korrigierten Strecke.

In a second aspect, the presented invention relates to an assembly method for assembling an object by means of a possible configuration of the assembly system presented, the method comprising:

1. a) moving the drive body by the drive in order to transmit a drive force provided by the drive through the connecting element to a mating connection element of a pipette,
2. b) determining first measured values of a movement of a movable element of the pipette relative to a base body of the pipette by means of the first sensor,
3. c) determining second measured values of a movement of the base body of the pipette relative to the drive body by means of the at least one second sensor,
4. d) comparing the first measured values with the second measured values in a mathematical calibration process,
5. e) determining a corrected distance of a movement of the movable element of the pipette on the basis of a result of the comparison in step d), and
6. f) detecting a placement of a fitting element arranged on the movable element of the pipette on the object using the corrected distance determined in step e).

The assembly method presented is used in particular to operate the assembly system presented, so that mutual reference can be made with regard to the advantages of the assembly method and the assembly system.

It can be provided that step f) comprises: comparing the corrected distance with a landing threshold value and detecting the placing of the fitting element arranged on the movable element of the pipette on the object.

A comparison of the corrected distance with a touchdown threshold value can be provided in particular for the case that the corrected distance is greater than or equal to the touchdown threshold value. For this purpose, it can be provided that the touchdown threshold value is determined on the basis of the corrected route or a predetermined touchdown threshold value is corrected on the basis of the corrected route.

Further advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each contribute individually or in any combination to the subject matter of the invention presented.

• 1 eine mögliche Ausgestaltung eines Bestückungssystems gemäß einer möglichen Ausgestaltung der vorgestellten Erfindung, und
• 2 eine mögliche Ausgestaltung eines Bestückungsverfahrens gemäß einer möglichen Ausgestaltung der vorgestellten Erfindung.

Show it:

• 1 a possible embodiment of an assembly system according to a possible embodiment of the presented invention, and
• 2 a possible embodiment of an assembly method according to a possible embodiment of the presented invention.

In 1 is a placement system 100 shown. The assembly system 100 comprises a drive body 101 going through a drive 103 is movable as indicated by arrow 105 indicated.

One through the drive 103 provided driving force is provided by a on the drive body 101 arranged connecting element 107 on one on a pipette 109 arranged mating connector 111 transferred so that the pipette 109 when the drive body moves 101 also moved.

Between the connecting element 107 and the mating connector 111 a "play" or a movement tolerance is provided, as indicated by arrows 113 indicated. Due to the "play" the mating connection element 111 particularly easy in the connecting element 107 be introduced.

Because of the "play" between the connecting element 107 and mating connector 111 leads one through the drive 103 provided drive force initially to a movement of the drive body 101 regardless of the pipette 109 until the fastener 107 with the mating connector 111 comes into contact. A correspondingly moves on the drive body 101 arranged first sensor 115 together with one on the drive body 101 arranged second sensor 117 relative to the pipette 109 .

The first sensor 115 is used to detect a movement of a movable element 119 relative to a base body 121 the pipette 109 and, as a result, a placement of one on the movable element 119 arranged placement element on an object.

The second sensor 117 is used to detect a movement of the base body 121 the pipette 109 relative to the drive body 101 .

Because one through the first sensor 115 detected movement is composed of a movement of the first sensor 115 relative to the pipette 109 and movement of the movable member 119 relative to the main body 121 According to the invention, it is provided that by means of a control device 123 based on by the second sensor 117 determined measured values of the movement of the drive body 101 relative to the pipette 109 the proportion of movement of the movable element 119 relative to the main body 121 in the by the sensor 115 detected movement is determined. For this purpose it is provided that the second sensor 117 determined second measured values of a movement of the drive body 101 relative to the pipette 109 first measured values of a movement of the movable element determined mathematically by the first sensor 119 relative to the main body 121 be matched. For this purpose, for example, one through the second sensor 117 determined second distance from one by the first sensor 115 determined first distance subtracted and / or by the first sensor 115 determined first distance through the by the second sensor 117 determined second distance can be divided. Of course, the second measured values can be compared with the first measured values by means of any further technically suitable mathematical operation.

The mathematical comparison of the first measured values with the second measured values results in a corrected distance of a movement of the movable element 119 which shows a significantly lower variance than the route determined only on the basis of the first measured values. Correspondingly, a position, in particular a drop-off point, of the movable element can be determined on the basis of the corrected route 119 can be determined particularly precisely.
Furthermore, due to the particularly low variance of the corrected distance, a potential movement path or a spring travel of one of the movable element 119 moving spring element 125 can be selected to be shorter than would be possible using the route determined only on the basis of the first measured values with a correspondingly large variance. Accordingly, the spring element can be provided in a particularly compact manner or with a particularly stiff spring characteristic.

Furthermore, due to the particularly low variance of the corrected distance, a relative to the movement of the movable element 119 determining value, such as, for example, a triggering threshold value, which a triggering mechanism of the pipette 109 activated, are specified with a lower tolerance and / or a lower base value than would be possible using the route determined only on the basis of the first measured values with a correspondingly large variance.

In 2 is a procedure 200 shown. The procedure 200 includes a movement step 201 for moving a drive body by means of a drive in order to transmit a drive force provided by the drive through a connecting element to a counter-connecting element of a pipette.

In a first determination step 203 become first measured values of a movement of a movable element 119 of the pipette is determined relative to a base body of the pipette by means of a first sensor.

In a second determination step 205 second measured values of a movement of the base body of the pipette relative to the drive body are determined by means of at least one second sensor.

In one adjustment step 207 the first measured values are compared with the second measured values in a mathematical comparison process.

In a third determination step 209 becomes a corrected distance of a movement of the movable element of the pipette on the basis of a result of the adjustment in the adjustment step 207 determined.

In one detection step 211 is a placement of a on a movable element 119 the placement element arranged in the pipette on the object using the in third determination step 209 determined corrected route detected. This is done, for example, in the third determination step 209 The determined corrected distance is compared with a predetermined touchdown threshold value and, in the event that a difference between the corrected distance and the touchdown threshold value is less than a tolerance limit, a touchdown of the movable element 119 reported to the pipette, ie a corresponding message is stored in a memory, for example, by a control device or transmitted to another device.

List of reference symbols

100

Assembly system

101

Drive body

103

drive

105

arrow

107

Connecting element

109

pipette

111

Mating connector

113

Bearings

115

first sensor

117

second sensor

119

movable element

121

Base body

123

Control device

125

Spring element

200

Procedure

201

Movement step

203

first determination step

205

second determination step

207

Adjustment step

209

third determination step

211

Detection step

Claims (10)

Assembly system (100) for assembling objects with assembly elements, wherein the assembly system (100) comprises: - a drive body (101) with a connecting element (107), - a drive (103), - a first sensor (115), - at least one second sensor (117), - a recording device (123). wherein the connection element (107) is configured to transmit a drive force to be provided by the drive (103) to a mating connection element (111) on a pipette (109), wherein the drive (103) is configured to move the drive body (101), the first sensor (115) for determining first measured values of a movement of a movable element (119) of the pipette (109) relative to a base body (121) of the pipette (109) is configured, wherein the at least one second sensor (117) is configured to determine second measured values of a movement of the base body (121) relative to the drive body (101), and wherein the control device (123) is configured to to compare the first measured values with the second measured values in a mathematical comparison process in order to determine a corrected distance of a movement of the movable element (119) of the pipette (109) and, on the basis of the corrected distance, a placement on the movable element (119) of the pipette ( 109) to detect placement element to be arranged on an object. Assembly system (100) Claim 1 , characterized in that the first sensor (115) is arranged on the drive body (101). Assembly system (100) Claim 1 or 2 , characterized in that the at least one second sensor (117) is arranged on the drive body (101). Assembly system (100) according to one of the preceding claims, characterized in that the control device (123) is configured to activate a triggering mechanism of the pipette (109) when the pipette (109) to be placed on the movable element (119) Placement element is detected on the object. Assembly system (100) according to one of the preceding claims, characterized in that a first reflective element is arranged on the movable element (119) of the pipette (109), with which the first sensor (115) interacts during a measurement, with the base body (121) of the pipette (109) is arranged at least one second reflective element with which the at least one second sensor (117) interacts during a measurement. Assembly system (100) according to one of the preceding claims, characterized in that the control device is configured to touch down in the event that the corrected distance of the movement of the movable element (119) of the pipette (109) is greater than or equal to a touchdown threshold of the movable element (119) on an object, wherein the control device (123) is further configured to determine the touchdown threshold based on the corrected distance or to correct a predetermined touchdown threshold value based on the corrected distance. Assembly system (100) according to one of the preceding claims, characterized in that the control device (123) is configured to subtract the second measured values from the first measured values and / or to divide the first measured values by the second measured values in the calibration process. Mounting method (200) for mounting an object by means of a mounting system (100) according to one of the Claims 1 to 7th , wherein the method comprises: a) moving (201) the drive body (101) by the drive (103) in order to transfer a drive force provided by the drive (103) through the connecting element (107) to a mating connection element (111) of a pipette (109 ), b) determining (203) first measured values of a movement of a movable element (119) of the Pipette (109) relative to a base body (121) of the pipette (109) by means of the first sensor (115), c) determining (205) second measured values of a movement of the base body (121) of the pipette (109) relative to the drive body ( 101) by means of the at least one second sensor (117), d) comparing (207) the first measured values with the second measured values in a mathematical calibration process, e) determining (209) a corrected distance of a movement of the movable element (119) of the pipette ( 109) on the basis of a result of the comparison in step d), and f) detection (211) of a placement of a fitting element arranged on the movable element (119) of the pipette (109) on the object using the corrected distance determined in step e). Assembly procedure (200) Claim 8 , characterized in that step f) comprises: comparing the corrected distance with a touchdown threshold value and detecting the touchdown of the fitting element arranged on the movable element (119) of the pipette (109) on the object. Assembly procedure (200) Claim 9 , characterized in that the touchdown threshold is determined on the basis of the corrected route or a predetermined touchdown threshold value is corrected on the basis of the corrected route.

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