Status indication lighting system for coordinate positioning machine

Abstract

A method of and system for conveying information to an operator of a coordinate positioning machine (10) is disclosed. The method comprises illuminating the working volume (11) of the machine (10) in dependence on the information. The information may comprise status information relating to the status of the machine (machine status information), such as an idle state, a warning state, a working state, a setup state, and an error state. The information may also comprise status information relating to the status of a part (9) in the working volume (part status information), such as a within tolerance state, and an out of tolerance state. Different colours of light may be used to convey or encode the information. Because the light source (20) illuminates the working volume (11) of the machine (10), this gives the impression of lighting up the whole machine (10). Since a large light source is effectively created in this way, machine status information (or any other type of information) is more easily visible from around the workshop environment. Another benefit is that machine status information, which may be a warning or error state, is more likely to be noticed by an operator who is directly viewing the working volume (11) from nearby.

Description

[0001] Status Indication Lighting System for Coordinate Positioning Machine

[0002] The present invention relates to a method of and system for conveying information to an operator of a coordinate positioning machine. Coordinate positioning machines include, for example, coordinate measuring machines (CMMs) and machine tools.

[0003] Figure 1 of the accompanying drawings shows a known type of coordinate positioning machine 10, comprising a moveable platform 12 and a fixed platform 14 that are supported and moved relative to each other by a plurality of telescopic or extendable legs 16 provided between them. The fixed platform 12 forms part of a fixed structure of the machine 10. The moveable and fixed platforms 12, 14 can also be referred to as stages, and the extendable legs 16 can also be referred to as struts. Where there are six such extendable legs 16 (as illustrated in Figure 1), the machine 10 is commonly called a hexapod.

[0004] Each extendible leg 16 is typically formed as a pair of tubes, with one tube being moved telescopically within the other by a drive mechanism (e.g. linear motor) to provide extension and retraction of the extendible leg 16, as indicated by the arrows within each extendible leg 16 and as described in more detail in WO 2017 / 174966. Various relative positions between the moveable platform 12 and the fixed platform 14 can be achieved by extending the legs 16 by differing amounts. A machine controller 15 operates to set the length of each extendible leg 16 to provide the required relative movement between the platforms 12, 14. By having six extendible leg 16, the relative position can be measured in six corresponding respective degrees of freedom (three translational degrees of freedom and three rotational degrees of freedom).

[0005] A workpiece 9 is mounted on the lower (fixed) platform 14 and a measurement probe 3 (or other type of tool) is mounted on the upper (moveable) platform 12. A working volume (or operating volume) 11 is defined between the upper (moveable) platform 12 and the lower (fixed) platform 14, with the measurement probe 3 being positioned (i.e. moved to a desired position) in the working volume 11 by operation of the extendible legs 16. The arrangement of Figure 1 can be referred to as a “bottom -up” arrangement because the extendible legs 16 extend up from the fixed platform 14 to the moveable platform 12. Alternatively, with a “top-down” arrangement the extendible legs 16 extend down from the fixed structure 14 to the moveable platform 12, with the measurement probe 3 mounted to a lower surface of the moveable platform 12 and a workpiece mounted to another part of the fixed structure 14 below that. These types of arrangement are discussed in more detail in WO 2019 / 073246 and WO 2021 / 074625.

[0006] The hexapod coordinate positioning machine of Figure 1 would typically be enclosed in a protective casing 13, as shown schematically in Figure 2 of the accompanying drawings. The protective casing 13 surrounds the working parts of the machine 10, e.g. the hexapod arrangement of extendable legs 16 and the moveable and fixed platforms 12, 14. The casing 50 would typically also incorporate one or more viewing windows 17 to provide visibility into the working volume 11 through the casing 13.

[0007] The machine 10 of Figure 2 also comprises a control panel 18 mounted on the outside of the casing 13, which can be used by an operator to control certain aspects of the machine 10 (for example in conjunction with the machine controller 15), and which can also be used to indicate the status of the machine 10, for example whether the machine is in an idle state, a working state (e.g. performing a measurement operation), a setup state, or an error state.

[0008] It has been previously considered to mount a more prominent beacon (or stack or Andon) light 19 externally, for example on the roof of the casing 13 as shown in Figure 2, in particular so that when the machine 10 is in an error state the beacon light can be activated (and optionally made to revolve to give the effect of a flashing light). Such an error status indication would be visible more than an error status indication on the control panel 18 and would be more likely to alert those within the general workshop or facility environment that attention is required.

[0009] However, the present applicant has appreciated that these previously-considered ways of providing status information to the operator (or to those working in the general environment) are often inadequate or insufficiently flexible, and has appreciated the desirability of providing a more effective and versatile method of conveying the status information of a coordinate positioning machine to a user.

[0010] According to a first aspect of the present invention, there is provided a method of conveying (or communicating) information to an operator of a coordinate positioning machine (located outside the working volume in the immediate or general vicinity of the machine), the method comprising illuminating (at least primarily) the working volume of the machine in dependence on the information.

[0011] Because the light source illuminates the working volume of the machine, this gives the impression of lighting up the whole machine. Since a large light source is effectively created in this way, machine status information (or any other type of information) is more easily visible from around the workshop environment.

[0012] Another benefit is that the machine status information, which may be a warning or error state, is more likely to be noticed by an operator who is directly viewing the working volume from nearby.

[0013] The information may comprise status information relating to the status of the machine. This may be referred to as machine status information.

[0014] The status information may comprise one or more of: an idle state, a warning state, a working state, a setup state, and an error state.

[0015] The information may comprise status information relating to the status of a part in the working volume. This may be referred to as part status information. The part may be one that is being measured by the machine. The status information may comprise one or more of: within tolerance state, and out of tolerance state.

[0016] Different colours of light may be used (for illuminating the working volume) to convey or encode the information. The method may comprise the step of encoding the information into a corresponding time sequence or pattern of one or more colours.

[0017] A time-varying light intensity and / or colour of light may be used to convey or encode the information.

[0018] The lighting may be emitted from a concealed light source.

[0019] The lighting may be emitted from a light source mounted internally within the machine.

[0020] The lighting may be visible from outside the machine.

[0021] The lighting that is visible to the operator may be primarily indirect lighting.

[0022] The lighting may be emitted from a light emitter or light source, such as an LED light source. The light emitter or light source may comprise one or more separate light emitters or light sources each for producing a different colour, which emitters or sources may be activated in different combinations to produce additional colours.

[0023] The coordinate positioning machine may be a hexapod coordinate positioning machine.

[0024] According to a second aspect of the present invention, there is provided a system for conveying information to an operator of a coordinate positioning machine, wherein the system is adapted to illuminate the working volume of the machine in dependence on the information. Additional features described above in connection with the first aspect of the present invention apply equivalently to the second aspect of the present invention.

[0025] According to a third aspect of the present invention, there is provided a coordinate positioning machine comprising a system according to the second aspect of the present invention or configured to perform a method according to the first aspect of the present invention.

[0026] According to a fourth aspect of the present invention, there is provided a computer program which, when run by a computer or a machine controller, causes the computer or machine controller to perform a method according to the first aspect of the present invention.

[0027] According to a fifth aspect of the present invention, there is provided a computer- readable medium having stored therein computer program instructions for controlling a computer or a machine controller to perform a method according to the first aspect of the present invention.

[0028] Reference will now be made, by way of example, to the accompanying drawings, in which:

[0029] Figure 1, discussed hereinbefore, is a schematic illustration of a non-Cartesian coordinate positioning machine;

[0030] Figure 2, also discussed hereinbefore, shows the non-Cartesian coordinate positioning machine of Figure 1 enclosed in a protective casing and with a control panel and beacon light mounted externally;

[0031] Figure 3 is a schematic illustration of a system embodying the present invention for providing status indication for the non-Cartesian coordinate positioning machine of Figure 2; Figure 4 is a schematic diagram showing the interaction and information flow between certain functional components of the system shown in Figure 3;

[0032] Figure 5 show several examples of how a system embodying the present invention is able to convey information through time-varying colours of light within the working volume of the machine;

[0033] Figure 6 is a schematic illustration of a system embodying the present invention for providing status indication for the non-Cartesian coordinate positioning machine of Figure 1; and

[0034] Figure 7 is a schematic illustration a system embodying the present invention for providing status indication for a Cartesian coordinate positioning machine.

[0035] Figure 3 shows a non-Cartesian coordinate positioning machine 10 that is generally similar to that described above with reference to Figure 2, so that a detailed description of like parts is not required. The machine 10 of Figure 3 differs from that of Figure 2 by incorporating a status indication system embodying the present invention, which provides an improved method of conveying information, such as status information, to a user or operator of the machine 10.

[0036] The system comprises a concealed light source 20 which is located internally within the confines of the machine 10 such that it is not directly visible to the operator (or is at least not particularly prominent) in normal use. More particularly, the light source 20 is in this embodiment mounted underneath the roof of the casing 13. LED (light emitting diode) strip lighting can conveniently be used as the light source 20, which has a relatively flat profile and which can be arranged to extend all the way around the generally triangular roof of the casing 13 to provide sufficient intensity of illumination. Whilst RGB LEDs can be operated to produce white light, the resulting white light can suffer from colour separation particularly on the machined surfaces, and therefore separate dedicated white LEDs (or some other type of white light source) can be used; dedicated white LEDs typically provide much clearer white light, as well as higher luminous intensity at a similar current compared to RGB LEDs. Tri-colour or bi-colour or single-colour LEDs can be used, and it has been found that tri-colour LEDs tend to have a higher luminous intensity than bi-colour LEDs.

[0037] The light source 20 is arranged to emit light in a generally downward direction, generally into the working volume 11 of the machine. In this way, the light source 20 primarily illuminates the working volume 11 of the machine 10, which has a rather dramatic and noticeable effect of appearing to light up the whole machine. Because a large light source is effectively created (the whole working volume is illuminated), the machine status is more easily visible from around the workshop environment. Another benefit is that the machine status (e.g. a warning or error state) is more likely to be noticed by an operator who is viewing the working volume. This is in contrast to the beacon (or Andon) light 19 or the control panel 18 discussed above with reference to Figure 2, which are mounted outside the working volume, and which might not be visible to the operator if they are directing their sight into the working volume.

[0038] Because the light source 20 is mounted internally, and is generally concealed, an operator positioned outside the machine 10 (and not necessarily within the immediate vicinity of the machine 10) will be viewing light emitted from the light source 20 only indirectly, for example via reflections off surfaces within the working volume 11 or off the casing 13 itself, via the window(s) 17 or the opening in the casing 13 at the front of the machine 10. This is in contrast to the beacon (or Andon) light 19 or the control panel 18 discussed above with reference to Figure 2, which is apparent to the operator is direct lighting. In other words, with the status indication of Figure 2, the operator will be seeing the light source itself, rather than secondary illumination from the machine 10 as in an embodiment of the present invention. The light source 20 is controlled by the control unit 21 in order to convey status information to the operator, and Figure 4 shows the components that are provided to achieve this. The machine controller 15 already mentioned above is modified (for example via operating instructions) to provide a status information unit 25 and an encoding unit 27. The status information unit 25 is operable to output status information 26 to the encoding unit 27, with the status information 26 relating to the status of the machine, for example whether the machine 10 is in an idle state (ready and waiting), a working state (e.g. performing a measurement routine), a setup state (e.g. performing a self-checking routine), or in an error state (for example after a machine crash in which the measurement probe 3 has inadvertently been driven into the fixed platform 14).

[0039] The encoding unit 27 is operable to encode the status information into an encoded format that represents the status information, and which is in a suitable form for transmission to the machine 10 via the transmitter unit Tx. For example, the encoded information 28 may be represented in binary format, with the idle, setup, working and error states being represented respectively as 00, 01, 10 and 11.

[0040] The encoded information 28 transmitted from the transmitter unit Tx is received at the machine 10 via the receiver unit Rx, and passed to the control unit 21. The control unit 21 is operable to generate one or more control signals 23 which are fed to the light source 20, to control the light emitted from the light source 20 depending on the original status information 26.

[0041] For example, when the status information 26 is intended to convey that the machine is in an idle state, the control signals 23 could be adapted to cause the light source 20 to emit a constant green light into the working volume 11, while for a setup state the control signals 23 could be adapted to cause the light source 20 to emit an intermittent (or flashing) blue light into the working volume 11. For a working state the control signals 23 could cause the light source 20 to emit a constant white light into the working volume 11, and for an error state the control signals 23 could cause the light source 20 to emit an intermittent (or flashing) red light into the working volume 11. A constant white light from the light source 20 could also or instead be used for general purpose machine lighting, and for this reason it may be most appropriate for the working state to be indicated by a white light from the light source 20, as suggested above. An off state could effectively be conveyed by emitting no light from the light source 20.

[0042] Various examples of this are shown in Figure 5, with each example represented as a time sequence or pattern of colours that are emitted by the light source 20, with R, G, B, W and - (long dash) representing Red, Green, Blue, White and Off respectively. For sequence (1) the light source 20 is off for the entire time duration shown, while for sequence (2) the light source 20 emits a continuous red light and for sequence (3) there is a constant blue light. For sequence (4) the light source 20 is controlled to emit red light alternately with being off, with a 1 : 1 mark-space ratio, while for sequence (5) it is white and off with a 2: 1 mark-space ratio. For sequence (6) the light source 20 is made to emit blue alternately with being off, with a 2:2 mark-space ratio, while for sequence (7) it is red, off, green alternatively, with a 1 : 1 : 1 mark-space ratio. Finally, for sequence (8) the control unit 21 controls the light source 20 to emit red, green and blue repeatedly in turn with a 1 : 1 : 1 mark-space ratio. Each of these time sequences or patterns can be used to represent a different status of the machine 10; for example, sequence (4) could be used to indicate an error status, and sequence (6) a setup status. There are of course countless other examples and ways in which the status information can be encoded into different time sequences of coloured lights.

[0043] Figure 6 is a schematic illustration of a system embodying the present invention for providing status indication for the non-Cartesian coordinate positioning machine of Figure 1, which differs from that of Figure 3 by not having a casing or enclosure 13. Instead, the light source 20 is mounted underneath the moveable platform 12, either to the underside of the platform 12 itself or (as illustrated) to the side of a downwardly extending collar fitted around the platform 12. In either case, the same principle applies as described above for the embodiment of Figure 3, which is that the light source 20 is arranged to illuminate primarily the working volume 11 of the machine 10, so that the operator of the machine 10 sees the status indication indirectly via the colour (or sequence of colours) of the working volume 11 rather than directly from the light source 20 itself. This is not to say that the light source 20 cannot be visibly directly to some extent, even if only from certain viewing positions, but the predominant effect is that it is the working volume 11 that is illuminated, without the light source 20 itself being particularly apparent. Operation of the embodiment shown in Figure 6 is entirely equivalent to what is described above in relation to the embodiment of Figure 3, so that a detailed description is not required.

[0044] The above description has focused on a hexapod type of coordinate positioning machine. Figure 7 shows the present invention embodied in another type of coordinate machine 1, having three linear axes x, y and z that are arranged orthogonally to one another in series, with the z axis being aligned with gravity g. A measurement probe 3 is mounted to a vertical column 8 which is slidable in the z direction within a carriage 2; this relative movement defines the z axis. The carriage 2 is itself supported on a horizontal beam 7 and is slidable in the y direction along the beam 7; this relative movement defines the y axis. In turn, the beam 7 is slidable in the x direction on a pair of rails 6; this relative movement defines the x axis. A machine controller 5 (equivalent to machine controller 15 of previous embodiments) operates to drive each component (column 8, carriage 2, beam 7) along its corresponding respective axis to the appropriate position to place the measurement probe 3 in the desired position within a working volume 11 of the machine 1, and to move it into a sensing relationship with a workpiece 9 which is supported on a fixed platform 4.

[0045] The coordinate measuring machine 1 of Figure 7 can be referred to as a Cartesian coordinate measuring machine because it has three linear axes x, y and z that are arranged orthogonally to one another. On the other hand, the coordinate measuring machine 10 of Figures 3 and 6 can be referred to as a non-Cartesian coordinate measuring machine because, in contrast to a Cartesian machine such as is illustrated in Figure 7, its axes are not arranged orthogonally according to a Cartesian coordinate system. The coordinate measuring machine 10 of Figures 3 and 6 can also be referred to as a “parallel kinematic” coordinate measuring machine, because its axes of movement are arranged in parallel. This is to be contrasted with the coordinate measuring machine 1 of Figure 7, which can be referred to as a “serial kinematic” coordinate measuring machine because its axes of movement are arranged instead in series. Another type of serial kinematic machine is an inspection robot or a manual articulating arm, with multiple articulating arm members connected in series by multiple rotary joints.

[0046] Operation of the embodiment shown in Figure 7 is entirely equivalent to what is described above in relation to the embodiment of Figure 3, so that a detailed description is not required. Although the working volume 11 of the machine 1 appears to be somewhat less well defined than for the machine of Figure 3 or Figure 6, in fact this is not so because it is understood to be any part of the machine 1 that is accessible in normal use by whatever tool (e.g. the measurement probe 3) that is supported on the column 8 and moved along the x, y, and z axes. In the embodiment shown in Figure 7, the working volume 11 can accordingly be considered to be the space above the fixed platform 4, up to the level of the beam 7. The light source 20, which in this example is affixed underneath the beam 7 but could be located elsewhere, is arranged to illuminate the working volume 11 in the same way as described above, so that this illumination is readily visible to an operator who is viewing the working volume 11 (for example monitoring an operation or adjusting a workpiece fixture), and also to those around the machine 1 in the general workshop environment.

[0047] It will be appreciated that an embodiment of the present invention is applicable to any type of coordinate positioning machine, and not just those of a type as shown in Figures 3, 6 and 7. For example, an embodiment of the present invention can also be used to convey information by illuminating the working volume of a machine tool, a robot, a manual articulating arm, a comparator, a scanning machine, a positioning device (e.g. for optical components), or a prototype manufacturing machine, or any other type of coordinate positioning machine. It will be appreciated that an embodiment of the present invention is applicable for conveying any type of information, not just machine status information. For example, the information could comprise time information, such that the working volume 11 could be illuminated on the hour, every hour, or every fifteen minutes, perhaps with a different colour or sequence of colours depending on the hour and / or minute, in order to provide a time reference to those working on or around the machine. Any information at all can be encoded by the encoding unit 27 and passed to the machine 10 for display via the light source 20.

[0048] The information could also be part status information, i.e. information relating to the status of the workpiece 9 (also referred to as a part) that is currently in the working volume. For example, referring to Figure 3, the part 9 loaded into the working volume 11 may have just had certain features machined in a machine tool in another part of the factory or facility, and the machine 10 may be measuring the part 9 using the measurement probe 3 in order to determine whether these features of the part 9 are within tolerance (“good part”) or out of tolerance (“bad part”). In this situation, the lighting system may be used to convey this part status information to the operator, for example by illuminating the working volume 11 in an amber lighting if the part 9 has been determined to be out of tolerance, and instead illuminating the working volume 11 in a green lighting if the part 9 has been determined to be within tolerance.

[0049] It will also be appreciated that an embodiment of the present invention can be used in combination with the previously-considered status indication systems as described above with reference to Figure 2, so it is not intended only as a complete replacement but could be used to complement what is provided by the previously-considered status indication systems.

[0050] A machine controller for controlling the operation of the coordinate positioning machine may be a dedicated electronic control system and / or may comprise a computer operating under control of a computer program. For example, the machine controller may comprise a real-time controller to provide low-level instructions to the coordinate positioning machine, and a PC to operate the realtime controller. It will be appreciated that operation of the coordinate positioning machine can be controlled by a program operating on the machine, and in particular by a program operating on a coordinate positioning machine controller such as the controller 8. Such a program can be stored on a computer-readable medium, or could, for example, be embodied in a signal such as a downloadable data signal provided from an Internet website. The appended claims are to be interpreted as covering a program by itself, or as a record on a carrier, or as a signal, or in any other form.

Claims

CLAIMS1. A method of conveying information to an operator of a coordinate positioning machine, the method comprising illuminating the working volume of the machine in dependence on the information.

2. A method as claimed in claim 1, wherein the information comprises status information relating to the status of the machine.

3. A method as claimed in claim 2, wherein the status information comprises one or more of: an idle state, a warning state, a working state, a setup state, and an error state.

4. A method as claimed in claim 1, 2 or 3, wherein the information comprises status information relating to the status of a part in the working volume.

5. A method as claimed in claim 4, wherein the status information comprises one or more of: within tolerance state, and out of tolerance state.

6. A method as claimed in any preceding claim, comprising using different colours of light to convey or encode the information.

7. A method as claimed in claim 6, comprising the step of encoding the information into a corresponding time sequence or pattern of one or more colours.

8. A method as claimed in any preceding claim, comprising using a timevarying light intensity and / or colour of light to convey or encode the information.

9. A method as claimed in any preceding claim, wherein the lighting is emitted from a concealed light source.

10. A method as claimed in any preceding claim, wherein the lighting is emitted from a light source mounted internally within the machine.

11. A method as claimed in any preceding claim, wherein the lighting isvisible from outside the machine.

12. A method as claimed in any preceding claim, wherein the lighting that is visible to the operator is primarily indirect lighting.

13. A method as claimed in any preceding claim, wherein the lighting is emitted from a light emitter or light source, such as an LED light source, optionally comprising one or more separate light emitters or light sources each for producing a different colour, which sources may be activated in different combinations to produce additional colours.

14. A method as claimed in any preceding claim, wherein the coordinate positioning machine is a hexapod coordinate positioning machine.

15. A system for conveying information to an operator of a coordinate positioning machine, the system being adapted to illuminate the working volume of the machine in dependence on the information.

16. A coordinate positioning machine comprising a system as claimed in claim 15 or configured to perform a method as claimed in any one of claims 1 to 14.

17. A computer program which, when run by a computer or a machine controller, causes the computer or machine controller to perform a method as claimed in any one of claims 1 to 14.

18. A computer-readable medium having stored therein computer program instructions for controlling a computer or a machine controller to perform a method as claimed in any one of claims 1 to 14.

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