Method for operating a pharmacy order-picking system

Abstract

The present disclosure relates to a method for operating a pharmacy order-picking device. The present method reduces the susceptibility of the pharmacy order-picking device to disruption. To detect a positioning deviation of the control appliance in the horizontal direction, at least one desired value of at least one reference position is made available, the control appliance is brought to a position corresponding to the desired value in the horizontal direction and, when a signal characteristic of a reference position is detected, an actual value of this reference position is determined. A desired value is compared with a corresponding actual value, or two actual values are compared with each other, and a deviation is determined. If a deviation is determined that exceeds a limit value, a signal pointing to the need for a correction is output. Depending on the deviation, automatic correction of the position deviation can be performed.

Claims

1. A machine-implemented method for detecting a positioning deviation of an operating unit in a pharmacy order-picking system, the method comprising: accessing a setpoint value corresponding to a reference position, the reference position comprising a physical location in the pharmacy order-picking system; approaching, using the operating unit, in a horizontal direction, the reference position; detecting a signal that is characteristic of the reference position; ascertaining an actual value of the reference position; comparing the setpoint value with the actual value; determining a horizontal deviation based on the comparison of the setpoint value and the actual value; and if the horizontal deviation exceeds a threshold value, outputting a signal indicating a need for a correction.

2. The method of claim 1, further comprising: accessing a second setpoint value corresponding to a second reference position; approaching, using the operating unit, in a vertical direction, the second reference position; detecting a second signal that is characteristic of the second reference position; ascertaining a second actual value of the second reference position; comparing the second setpoint value with the second actual value; determining a vertical deviation based on the comparison of the second setpoint value and the second actual value; and if the vertical deviation exceeds the threshold value, outputting a signal indicating the need for a correction.

3. The method of claim 2, further comprising: rotating the operating unit by a predefined value C on detection of a positioning deviation of the operating unit with respect to a vertical axis of rotation after detection of the horizontal deviation; approaching, using the operating unit, a third reference position corresponding to a third setpoint value; detecting a third signal that is characteristic of the third reference position; ascertaining a third actual value of the third reference position; comparing the third setpoint value with the third actual value; determining a second horizontal deviation based on the third setpoint value and the third actual value; and if the horizontal deviation and the second horizontal deviation exceed the threshold value, or if the horizontal deviation and the second horizontal deviation differ by a predefined value, outputting the signal indicating the need for the correction.

4. The method of claim 1, further comprising: responsive to outputting the signal indicating correction is needed, transmitting a service query electronically to a service employee; and shutting down the pharmacy-order picking system.

5. The method of claim 1, wherein the pharmacy order-picking system comprises a control unit, and setpoint values are stored as predefined values in the control unit.

6. The method of claim 1, wherein the pharmacy order-picking system comprises a control unit, and the method further comprises: upon an initial startup of operation of the pharmacy order-picking system, approaching predefined reference positions; detecting a signal that is characteristic of each of the predefined reference positions; ascertaining a setpoint value; and storing the ascertained value in the control unit.

7. The method of claim 1, further comprising: approaching the reference position at a first speed until the setpoint value is reached; and approaching the reference position at a second speed until the signal that is characteristic of the reference position is reached, wherein the second speed is lower than the first speed.

8. A method for operating a pharmacy order-picking system, the method comprising: ascertaining an actual value of a reference position, the reference position comprising a physical location in the pharmacy order-picking system; comparing the actual value of the reference position with a stored setpoint value corresponding to the reference position; determining a horizontal deviation based on the comparison of the stored setpoint value and the actual value; and if the horizontal deviation exceeds a threshold value, outputting a signal indicating correction is needed.

9. The method of claim 8, further comprising: ascertaining a second actual value of a second reference position; comparing the second actual value with a second stored setpoint value corresponding to the second reference position; determining a vertical deviation based on the comparison of the second stored setpoint value and the second actual value; and if the vertical deviation exceeds a threshold value, outputting a signal indicating correction is needed.

10. The method of claim 8, further comprising: responsive to outputting the signal indicating correction is needed, transmitting a service query electronically to a service employee; and shutting down the pharmacy-order picking system.

11. The method of claim 8, wherein the pharmacy order-picking system comprises a control unit, and setpoint values are stored as predefined values in the control unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A method described herein is described in greater detail below on the basis of preferred embodiments that are shown only schematically in the drawings, in which:

(2) FIG. 1 illustrates a lateral sectional view of a shelf unit of a pharmacy order-picking system.

(3) FIG. 2 illustrates a top view of a pharmacy order-picking system.

(4) FIG. 3 illustrates a sectional view of a pharmacy order-picking system.

(5) FIGS. 4a-4c illustrate sectional views of a section of a pharmacy order-picking system, wherein the figures are to be used to illustrate a method described herein.

(6) FIG. 5a-5b illustrate sectional views of one section of a pharmacy order-picking system, wherein the figures are supposed to illustrate a method described herein.

(7) FIG. 6 illustrates a schematic view of one section of a pharmacy order-picking system wherein the figure should serve to illustrate a method described herein.

DETAILED DESCRIPTION

(8) FIG. 1 illustrates a lateral sectional view of a pharmacy order-picking system having two shelf units, but only one shelf unit 10 is shown here. The pharmacy order-picking system also includes an operating unit 20 that can be moved horizontally and vertically between the shelf units 10. The shelf units each comprise a plurality of shelves 11 extending in the horizontal direction (X axis) and a plurality of shelf walls 12 extending in the vertical direction (Z axis). The shelves 11 are usually made completely of glass with a smooth surface. Drug packages 22 are stored in a chaotic fashion on the shelves 11 with optimal utilization of space.

(9) The operating unit 20 can be moved horizontally and vertically between shelf units 10 with the help of two horizontal guide rails (13a, 13b) and one vertical guide rail (14) and the drive units assigned to them. The vertical guide rail 14 is movably attached to the horizontal guide rails 13a, 13b for this purpose. The operating unit 20 includes a gripping device 21, which can be moved vertically on the guide rail 14 by means of a corresponding drive mechanism as well as a gripper jaw and/or a vacuum gripper. The gripping device 21 also includes a sensor 23 with which the distance from the sensor to the back wall (see FIG. 2) of the shelf unit, stored drug packages 22 or components of a shelf unit (shelf walls, shelves), can be determined.

(10) The sensor 23 may be, for example, an optical sensor according to the triangulation method which determines the distance from the plane spanned by the two horizontal guides at a 90° angle (ideal value, positioning deviations possible; see FIGS. 5a, 5b in this regard). In another embodiment, an inductive proximity sensor may be used, with metallic reference points to be used in this case.

(11) The operating unit 20 is electronically connected to a control unit 30, which is shown only schematically here. The control unit 30 may comprise a plurality of computers (not shown) and controls the entire operation of the system (identification, placement on a shelf and retrieval from the shelf, etc.).

(12) With the pharmacy order-picking system shown in FIG. 1, seven reference positions (X1, X2, X3, X4, X5, Z1, Z2) are provided (reference position X4 is situated on the shelf unit, which is not shown and therefore is not “visible” in FIG. 1). However, this number of reference positions may be necessary when all of the positioning deviations described below are to be ascertained—in other embodiments, it may be adequate to have only one reference position.

(13) Reference positions may be provided by any points that can be detected by the sensor within the pharmacy order-picking system. In the following description of the method, it is assumed that the reference positions are provided by shelves (positions Z1, Z2) and walls (positions X1, X2, X3, X4, X5). The reference positions in this case are therefore not additional structural measures. In other embodiments the reference positions may also be provided by specific components (signal generators, etc.).

(14) FIG. 2 illustrates a top view of a section of a pharmacy order-picking system wherein the two parallel shelf units 10, 10a are visible in this figure, with the operating unit 20 being movable horizontally and vertically between them with the help of the guide rails 13a, 13b, 14. For placing drug packages on the shelf or retrieving them from the shelf, the gripping device 21 of the operating unit 20 is aligned at a 90° angle to the back wall 16, 16a of the corresponding shelf unit 10, 10a. The operating unit 20 is itself high-maintenance and cost-intensive, so it is customary to install just one operating unit for two parallel shelf units in a pharmacy order-picking system. To be able to operate the two shelf units, the gripping device can be rotated about an axis of rotation C, as indicated in FIG. 2. The reference position X4, which is not “visible” in FIG. 1, is provided by a component of the shelf unit 10a (shelf wall 12).

(15) FIG. 3 illustrates a sectional view of the pharmacy order-picking system. The operating unit 20 can be moved horizontally and vertically on guide rails 13a, 13b between the two shelf units 10, 10a. Those skilled in the art are familiar with details of how the operating unit can be moved on the guide rails, so these details are not essential to the present disclosure. The vertical guide rail 14 is usually moved on the horizontal guide rails 13a, 13b with the help of one or two toothed belts and one or more drives. Likewise, the gripping device 21 together with the sensor 23 is usually moved vertically on the vertical guide rail 14 with the help of a toothed belt and a corresponding drive.

(16) With reference to FIGS. 4a-4c, 5a-5b and 6, embodiments of a method described herein are described below. The diagrams of sections of a pharmacy order-picking system selected to illustrate a method described herein are highly schematic, in order not to obscure the nature of a method described herein due to unnecessary structural details.

(17) X-Axis Positioning Deviation

(18) With reference to FIGS. 4a-4c, one embodiment of a method described herein is described below, this embodiment regarding positioning deviations with regard to the X axis.

(19) A positioning deviation with respect to the X axis can be detected in general on the basis of one reference point (based on a benchmark). However, no conclusion can be drawn about the type of deviation on the basis of this one deviation detected (elongation in length of toothed belts, mechanical slippage, etc.). Therefore, an embodiment of a method described herein, in which two reference points (X2, X3) for ascertaining a positioning deviation are verified, is described below.

(20) FIGS. 4a-4c illustrate a schematic sectional view of one section of a pharmacy order-picking system having two shelf units 10, 10a and one operating unit that can be moved horizontally and vertically between the shelf units; only the gripping device 21 is indicated schematically for the sake of simplicity. The view according to the aforementioned figures shows the lower portion of the pharmacy order-picking system, and therefore only the reference positions X2, X3 and X4 are indicated.

(21) The numerical data given in the figures refer to the X component of the space coordinates of various reference positions, where only the numbers that are intended to illustrate the method as such.

(22) In a method described herein for operating a pharmacy order-picking system, two setpoint values X.sub.2S, X.sub.3S for the reference positions X2, X3 of shelf unit 10a are provided for detecting a position deviation of the operating unit in the horizontal direction (X axis). The setpoint values of the aforementioned reference positions are each embodied in FIGS. 4a-4c in the unit labeled as “setpoint” at the left (X.sub.2S=10, X.sub.3S=45).

(23) As mentioned above, the setpoint values mentioned above can be provided by storing them only in the memory of the control unit or by having them learned at the time of (initial) start of operation of the pharmacy order-picking system. In the (initial) start of operation, the operating unit is therefore moved from a reference position, the position of which is predetermined (e.g., the “zero point” of the operating unit) at a first speed (preferably the maximum speed of the operating unit in the X direction) to a preliminary position X.sub.2V which corresponds to the first setpoint value X.sub.2S. Beyond this preliminary position X.sub.2V, the operating unit with the sensor turned on is moved further in the direction of the reference position X2. As soon as the reference position has been reached, the sensor detects a characteristic signal. In the exemplary embodiment shown here, the reference position X2 is provided by a shelf wall, and the sensor detects a characteristic signal (change in flank in the digital output signal or change in level with an analog output signal). The space coordinates (or at least the X component thereof) is saved as the setpoint value X.sub.2S for the reference position X2. Accordingly, the movement is performed using the reference position X3, and it is not necessary to return the operating unit to the reference point. According to FIG. 4a, the reference positions X2 and X3 are approached from the left. However, that is not necessary. In the method, it is irrelevant from which side the reference positions are approached with the sensor turned on.

(24) After providing the setpoint values for the reference positions X2, X3, the operating unit 20 approaches a position corresponding to the setpoint value X.sub.2S in the horizontal direction. The aforementioned position X.sub.2V is situated at X coordinate 5. With the sensor turned on, the operating unit is now moved further toward the setpoint value and on detecting a signal that is characteristic of the reference position X2, an actual value X.sub.2I is ascertained for the reference position X2. As soon as the actual value for the reference position has been ascertained, the operating unit is moved to a position X.sub.3V corresponding to the setpoint value X3 and the operating unit 20 is moved further in the direction of the reference position X3 starting from this position, and on detecting a signal that is characteristic of the reference position X3, an actual value X.sub.3I for this reference position is ascertained.

(25) The actual values X.sub.2I, X.sub.3I thereby ascertained are compared with the corresponding setpoint values X.sub.2S, X.sub.3S and one deviation is ascertained per reference position X2 and X3 (A.sub.X2, A.sub.X3). A deviation may also be determined by subtracting the two actual values thereby ascertained for the reference positions X2, X3 from one another (e.g., the distance between the actual values X.sub.2I, X.sub.3I is ascertained) and the value thereby ascertain is compared with the difference in the corresponding setpoint values.

(26) If a deviation A.sub.X2, A.sub.X3, A.sub.X23 which exceeds the limit value is ascertained, a signal indicating the need for a correction is output. For example, it may be displayed to the user that a positioning deviation with respect to the X axis has been ascertained and the service has been informed accordingly. If the deviations thereby ascertained no longer allow reliable operation of the system, the system is stopped and the service is informed.

(27) The deviations thereby ascertained allow inferences regarding the type of disturbance in the positioning accuracy. In the case illustrated in FIG. 4a, the actual values for the reference positions X2, X3 correspond to the setpoint values. It follows from this that there is not any disturbance in the positioning accuracy with regard to the X axis. In the case illustrated in FIG. 34b, a deviation A.sub.X2=1 is ascertained with respect to the reference position X2, and a deviation A.sub.X3=5 is ascertained with regard to the reference position X3, from which it is possible to conclude that there has been an elongation in the length of the tooth belt(s) of the drive mechanism for the X axis. On the basis of the deviations thereby ascertained, a correction factor which can be used in the further positioning of the operating unit may be ascertained.

(28) In the case illustrated in FIG. 4c, a deviation A.sub.X2, A.sub.X3=2 is ascertained for each of the two reference positions X2, X3. It follows from this that there is no elongation in the length of the toothed belt(s) of the drive mechanism for the movement of the operating unit in the X direction, but there is an offset which indicates a mechanical slippage or a jumping of the tooth belt over a corresponding drive gear.

(29) C Axis Positioning Deviation (Axis of Rotation of the Gripping Device and the Operating Unit)

(30) With reference to FIGS. 4a, 5a, 5b, one embodiment of a method described herein is described below in which the positioning accuracy with regard to the C axis (axis of rotation of the gripping device of the operating unit) is ascertained.

(31) In this embodiment of a method described herein, first the setpoint values for the reference positions X3, X4 are provided as described above. Next the positioning deviation with regard to the reference X3 is ascertained in the manner already described with reference to the X axis. A position deviation with regard to the X axis is then ascertained at a reference position X4 of the other shelf unit 10.

(32) To do so, the grouping device 21 of the operating unit is rotated by a predetermined value C with this rotation by the predetermined value C corresponds to a rotation by 180° in the ideal case. Then a second position X.sub.4V corresponding to a second setpoint value X.sub.4S is approached with the operating unit. In the schematic diagrams shown in FIGS. 4a, 5a-5b, this position X.sub.4V is at the right of the reference X4. With the sensor turned on, the operating unit is then moved further in the direction of the reference position X4, and an actual value X.sub.4I of the reference position is ascertained on detecting a signal that is characteristic of the reference position X4. Next, the setpoint value of the second reference position X4 is compared with the actual value and a deviation A.sub.X4 is determined. If the deviations ascertained for the reference positions X3 and X4 exceed limit values or if they are different by a predefined value, then a signal indicating the need for a correction is output.

(33) The type of positioning deviation can be deduced from the ascertained deviations A.sub.X3, A.sub.X4. In the case illustrated in FIG. 4a, the deviations for the reference positions X3 and X4 are both the same (they are both 0), which means that there is no positioning deviation with respect to the C axis of rotation (if other positioning deviations with respect to the X axis can be ruled out).

(34) FIG. 5a illustrates a case in which the gripping device 21 is not oriented at a 90° angle to the shelf unit 10a but instead the angle to the shelf unit is adjusted slightly clockwise. In determining the actual value for the reference position X3, therefore this is not detected at X=45 (as would be the case with a 90° angle), but instead is detected only at X=46. After rotation at the gripping device 21 by a value C (corresponding to the ideal angle of 180° in this case), the actual value for the reference position X4 is determined. Based on the faulty positioning of the gripping device with respect to the shelf unit 10, the actual value of the reference position at x=44 is determined. A comparison at the setpoint values with the actual values for the reference positions X3, X4 shows that the deviations are the same (A.sub.X3, A.sub.X4) and are greater than 0, which indicates a false position of the gripping device 21 with respect to the shelf walls.

(35) FIG. 5b illustrates a case in which the rotation by the amount C is not rotation by 180° but instead is by a reduced angle. With regard to the reference position X3, a deviation of A.sub.X3=0 is determined and for the reference position X4, a deviation of A.sub.X4=1 is determined. If faultless positioning with regard to the X axis is assumed, this means that the rotation by the value C does not result in rotation by 180°, so that positioning accuracy with regard to the C axis is disturbed.

(36) Z-Axis Positioning Deviation

(37) Referring to FIG. 6, one embodiment of a method described herein will now be described briefly. In this embodiment a positioning deviation with regard to the Z axis is also determined.

(38) A positioning deviation with regard to the Z axis can be determined in general according to the positioning deviation with regard to the X axis. That is, either a positioning deviation starting from a reference point is determined with respect to the reference positions Z1, Z2 or a difference in the actual values of the reference points Z1, Z2 is determined and this is compared with the difference between the setpoint values of the reference points Z1 and/or Z2. If a deviation between the difference in the setpoint values and actual values is detected, one can conclude from this that there has been an increase in the length of a tooth belt that has been used, if any, for positioning the gripping device 21. The details regarding the performance of the method for determining a positioning deviation in the Z axis are comparable with those of the method for determining a positioning deviation with regard to the X axis, so that a renewed detailed presentation will not be given here.

(39) To determine whether there is an inclined position of the vertical guide rail, positioning deviations in two reference positions with different Z axis positions are determined. In the present case, a possible inclined position of the Z axis can be determined, in which positioning deviations with regard to the X axis are determined for the reference positions X1, X2 or X3, X5. In the determining of a possible inclined position of the Z axis, the two measured reference positions should be situated on a shelf unit to rule out possible influences due to a positioning deviation with regard to the C axis of rotation of the gripping device. The possible positioning deviations with regard to the two reference positions are compared and in the event of a deviation in these from one another, an inclined position of the Z axis (vertical guide rail) can be concluded and when a limit value is exceeded, a signal indicating the need for a correction is output.