Method for transmitting information to a measuring probe and corresponding measuring probe

Abstract

A method of communicating information to a measurement probe attached to a coordinate positioning machine is disclosed, the method comprising the steps of encoding the information as one or more of a plurality of characteristic movements of the probe, controlling the machine to impart movement to the probe, detecting movement at the probe, and decoding the information at the probe from the detected movement. A measurement probe for use in such a method is also disclosed, the measurement probe being mountable to the machine and comprising at least one movement sensor for sensing movement imparted to the measurement probe by the machine, and a controller for determining whether the sensed movement includes one or more of a plurality of characteristic movements of the probe and performing an action on or controlling the movement of the probe in response to the determination.

Description

[Technical Field]

[0001] The present invention relates to measurement probes, such as wireless measurement probes, for use on coordinate positioning machines, such as machine tools, coordinate measuring machines, and measuring robots. Examples of measurement probes are touch trigger probes, scanning probes, or analogue probes. The present invention is also applicable to other types of measurement devices, such as tool setters. The present invention also relates to a method of transmitting information to such measurement probes attached to such coordinate positioning machines. [Background technology]

[0002] Computer numerically controlled (CNC) machine tools are widely used in the manufacturing industry for machining or cutting parts. It is known to replace the cutting tool on such machine tools with a measurement probe to allow measurement of the part or tool for setup or inspection purposes. Such a measurement probe may be a contact probe having a workpiece-contacting stylus for measuring the position of a point on the surface of a workpiece, such as those described in U.S. Pat. Nos. 4,145,816 and 4,153,998. Without a workpiece-contacting stylus, any of these types of probes may alternatively sense the workpiece using optical, capacitive, inductive (e.g., using eddy currents), or other non-contact techniques.

[0003] Because measurement probes for use with machine tools are interchangeable with cutting tools, providing wires or cables to connect the probe's output signal to the machine tool controller can be difficult. As a result, various wireless signal transmission techniques are typically used, including inductive transmission, optical transmission, and radio transmission. An example of an optical transmission system between a probe and a machine tool controller is shown in U.S. Pat. No. 5,150,529, while WO 2004 / 057552 provides an example of a wireless measurement probe that communicates with a remote probe interface via a spread spectrum radio link. Additionally, in the absence of wires or cables, the probe must be battery-driven.

[0004] As measurement probes become more complex over the years, they are required to operate in a variety of modes. For example, such measurement probes may include electronics for filtering signals they capture before transmitting them to a controller to prevent the generation of spurious signals, e.g., as a result of vibrations. As such, probes may have various operating modes (e.g., with or without filtering) and may be pre-configured to use different modes depending on the machine tool and the environment in which they are installed. Because wireless measurement probes for machine tools are battery-operated, the probes may also include various power saving modes to preserve battery life.

[0005] Furthermore, before wireless communication between the probe and the controller can even occur, the wireless communication interface for the probe must be set up. For example, in the case of a wireless probe, the frequency channel and communication protocol must be configured on both the probe and the controller to ensure that the probes can communicate with each other. However, the wireless interface cannot be used as a means of configuring the probe before wireless communication mode is established.

[0006] In known probes, such modes can be pre-set by using DIP switches on a circuit board internally within the probe. However, the use of DIP switches has many drawbacks, and WO 2002 / 063235 describes an improvement in the form of so-called "trigger-logic" technology, which provides an easier way of programming the operating modes of a measurement probe. With this technology, an indicator (e.g., an LED) on the measurement probe flashes to indicate mode information, and manual deflection of the probe's stylus is used to set the desired probe operating mode.

[0007] However, although the "Trigger Logic" technique allows for easy programming of the measurement probe without the need to access internal DIP switches etc., the Applicant has found that programming can become complicated when a large number of parameters in the measurement probe need to be programmed or when the measurement probe has a large number of modes to be set, which can lead to programming errors and make the programming process time consuming. Summary of the Invention

[0008] According to a first aspect of the present invention, there is provided a method of communicating information to a measurement probe attached to a coordinate positioning machine, the method comprising the steps of encoding (and / or representing) the information as one or more of a (e.g. predetermined) plurality (e.g. available or selectable) characteristic (and / or distinct and / or identifiable and / or distinguishable) movements of the probe (e.g. by selecting from the following): controlling a machine to impart movements to the probe; detecting the movements of the probe; and decoding (and / or determining and / or reconstructing) the information from the detected movements of the probe.

[0009] This has the advantage of using existing mechanisms (i.e., machine movements) rather than separate communication channels that may not yet be configured. Furthermore, due to the availability of multiple characteristic movements to choose from when encoding information, a rich variety of information can be represented and conveyed in this manner. For example, combinations or sequences of movements selected from the available characteristic movements can be used to form complex instruction sets for the probe, or to communicate configuration data or initiate communication.

[0010] According to a second aspect of the present invention, there is provided a measurement probe for use in a method according to the first aspect of the present invention, the measurement probe being mountable to a machine and comprising at least one movement sensor for sensing movement imparted to the measurement probe by the machine, and a controller for determining whether the sensed movement comprises one or more of a plurality of characteristic movements of the probe, and performing an action on or controlling movement of the probe in response to the determination.

[0011] The information may be encoded or represented as a sequence of two or more of a plurality of characteristic movements.

[0012] A characteristic movement of a probe (or a sequence of such characteristic movements) may be one that is not a normal movement or sequence of movements that a probe would make during normal operation (e.g., when measuring a workpiece, or when moving around a working volume, or when moving to or from a tool changer rack, etc.) For example, rotation of the probe about its longitudinal axis will typically not be a movement made during normal operational use of the probe.

[0013] A characteristic motion need not be specific in all respects, but can instead be associated with a characteristic type or range of motion. For example, clockwise rotation at any rotational speed can be used as a characteristic motion because it can be distinguished from counterclockwise rotation at any rotational speed. Thus, two motions or types of motion can be considered characteristic if they can be distinguished from one another (particularly in a probe using an appropriate motion sensor). However, clockwise rotation in the range of 100-300 rpm does not constitute a characteristic motion relative to clockwise rotation in the range of 200-400 rpm, because the overlapping ranges (in the same rotational direction) mean that these motions cannot be distinguished (in the probe) from one another. Therefore, the property of being a characteristic motion can be considered relative to another motion or type of motion.

[0014] The method may comprise performing an action in the probe or controlling the operation of the probe in response to information decoded in the probe.

[0015] This information is (a) configuration data for the probe, and (b) one or more commands, operations, or instructions to be performed by the probe; It may include at least one of:

[0016] The method may comprise using one or more movements as a command or instruction to put the probe into a data reception mode, during which one or more further movements may be used to communicate data to the probe.

[0017] The method may comprise using one or more movements as a command or instruction to place the probe into a data transmission mode during which the probe may communicate data to a machine controller or machine interface.

[0018] The probe may use a sequence of trigger pulses to transmit data to a machine controller or machine interface.

[0019] This data may include probe configuration data.

[0020] The method may comprise configuring the probe using the data received at the probe.

[0021] The step of encoding (or representing) the information may comprise selecting one or more movements that represent (or correspond to) the information from a plurality of predetermined characteristic movements.

[0022] The predetermined characteristic movements may be stored in a lookup table.

[0023] The predetermined characteristic movements may be presented in an instruction manual, for example a user instruction manual.

[0024] The step of encoding (or representing) the information may include using a predetermined algorithm (e.g., an encoding algorithm) to encode or convert the information into a corresponding set or sequence of one or more movements performed by the probe. The algorithm may be adapted to encode different information (having different information content) into different sets or sequences of one or more movements performed by the probe. In this way, different information (having different information content) can be distinguished in the probe. The algorithm may be adapted to receive multiple types of information (e.g., multiple commands transmitted to the probe) and encode different types of information (e.g., different commands) into different respective movements performed by the probe.

[0025] The method may be adapted to process multiple types or items of information (e.g., various commands to be performed by the probe, or different configuration data for the probe, etc.) and to encode the various types or items of information (e.g., various commands, or configuration data, etc.) into various respective movements of the corresponding probe.

[0026] The one or more movements may include at least one rotational movement of the probe, and / or at least one translational movement of the probe.

[0027] The or each movement may be a rotational movement of the probe.

[0028] The method may include detecting one or more movements using (e.g., signals from) at least one movement sensor on the probe.

[0029] The method may comprise using (eg, signals from) at least one motion sensor on the probe to distinguish between various ones of the one or more motions.

[0030] The method may include using at least one movement sensor on the probe (e.g., signals therefrom) to distinguish one or more movements of the probe from other movements (e.g., normal movements occurring during normal use of the probe).

[0031] The at least one motion sensor may include at least one accelerometer.

[0032] The at least one motion sensor may include at least one linear accelerometer.

[0033] The method may include using at least two accelerometers (e.g., signals therefrom) on the probe positioned substantially orthogonal to one another to detect movements and / or distinguish those movements from other movements of the probe.

[0034] The method may include using at least three accelerometers (e.g., signals therefrom) on the probe arranged substantially orthogonal to one another to detect movements and / or distinguish those movements from other movements of the probe.

[0035] The probe may include at least one of an axial accelerometer for measuring acceleration along the axis of the probe, and first and second radial accelerometers for measuring in first and second substantially orthogonal radial directions, respectively, toward the probe axis (as caused by rotation of the probe about the probe axis).

[0036] The machine may be operable to rotate the probe about an axis of rotation of the machine.

[0037] The movement may include at least one rotational movement about an axis of rotation of the machine.

[0038] The probe may be mounted on the machine with the probe axis substantially aligned with the axis of rotation of the machine.

[0039] The machine may include an articulating probe head to which the probe is attached, and the axis of rotation of the machine may be selected from one or more axes of rotation in the probe head.

[0040] The, or each, movement may be distinguishable from one another by the probe.

[0041] The, or each, movement may be distinguishable by the probe from other movements made by the probe.

[0042] The movement, or each movement, (a) the characteristics of the movement, such as its speed and / or duration; (b) the type of motion, such as whether it is a clockwise or counterclockwise rotation; (c) the magnitude of acceleration, (d) direction of acceleration, (e) speed or velocity of movement, (f) direction of movement; (g) duration of the movement; (h) timing of movements; (i) the order of movements within a movement sequence, and (j) The temporal relationship between the movement and one or more other movements in the movement sequence. A motion may be characterized (and / or distinguishable from one another) by one or more of the following: whether one motion, or type of motion, is distinguishable from another motion, or type of motion, is particularly important from the perspective of the probe, where motion detection, identification, and analysis are performed. It should also be noted that motions may be characterized by a range of characteristic values ​​(e.g., a rotational speed of 100-200 rpm, a rotational speed greater than 300 rpm, or a duration of 3-7 seconds) rather than a specific value of the characteristic (e.g., a rotational speed of exactly 100 rpm), although in practice even a specific characteristic value will typically fall within a narrow range of values ​​due to measurement and motion control tolerances.

[0043] The movement may include rotational and / or translational movement.

[0044] There may be multiple different movements or combinations of movements to choose or select in the encoding or representation step, each corresponding to a different respective action performed by the probe.

[0045] Each movement, or combination of movements, may correspond to a different respective identifiable signature.

[0046] The method may comprise the step of attaching the measurement probe to the machine before controlling the machine to impart one or more movements to the probe.

[0047] The decoding step performed in the probe may be based solely on movements detected in the probe after it has been attached to the machine, or at least may only take into account information derived from movements detected in the probe after it has been attached to the machine. This is to be distinguished from the scenario where movements are imparted by a manual operator, who may induce the probe to be powered on or misconfigured, for example when attaching the probe to a machine tool changer.

[0048] The measurement probe may be a wireless measurement probe.

[0049] The measurement probe may be adapted to measure the position of a point on the surface of an object. The measurement probe may be a contact probe having a deflectable stylus. A sensor may then measure the deflection of the stylus. The measurement probe may be a non-contact probe (e.g., an optical, inductive, or capacitive probe). The measurement probe may be a touch-trigger probe. The measurement probe may be a scanning probe or an analogue probe. The measurement probe may be configured to measure a workpiece. For example, the measurement probe may include a shank that allows it to be attached to a spindle of a machine tool. That is, the measurement probe may include a spindle-mountable measurement probe. The measurement probe may be attached elsewhere on the machine tool.

[0050] A measurement probe is also called a dimensional measurement probe or a probe for sensing the position of an object (one or more points on it).

[0051] The measurement probe may be a measurement device, such as a measurement probe or a tool setter. Thus, the first aspect of the present invention is applicable to any type of measurement device. The tool setter may be an optical tool setter (e.g., a non-contact laser tool setter). The tool setter may be attached to the bed of a machine tool.

[0052] The measurement probe may be battery powered (eg, the measurement probe may include one or more internal batteries for powering the control circuitry, the primary wireless communication module, etc.).

[0053] The coordinate positioning machine may be a machine tool.

[0054] The rotation axis of the machine may be the rotation axis of a spindle of a machine tool.

[0055] The probe may be mounted on the machine tool with the probe axis substantially aligned with the spindle axis of the machine tool.

[0056] The method of communicating information to the probe may provide a secondary communication means, but there is also a primary communication means that is different from the secondary communication means, and the primary communication means is used to communicate during normal use of the probe, for example to communicate measurement data during measurement operations.

[0057] The primary communication means may include a wireless communication means, such as optical or radio.

[0058] Probe movements may be considered distinctive (or distinct or distinguishable) if each (eg, rotational) movement is distinguishable by the probe from each other (eg, rotational) movement.

[0059] According to a third aspect of the present invention, there is provided a method of controlling a measurement probe mounted on a coordinate positioning machine, the method comprising the steps of communicating information to the probe using a method according to the first aspect of the invention, and performing an action on or controlling the operation of the probe in response to the decoded information.

[0060] According to a fourth aspect of the present invention, there is provided a measurement probe configured for use with a method according to the first aspect of the present invention.

[0061] According to a fifth aspect of the present invention, there is provided a machine controller configured to use a method according to the first aspect of the present invention.

[0062] According to a sixth aspect of the present invention, there is provided a computer program which, when executed by a computer or machine controller or probe controller, causes the computer or machine controller or probe controller to carry out or at least use a method according to the first aspect of the present invention. The program may be carried on a carrier medium. The carrier medium may be a storage medium. The carrier medium may be a transmission medium.

[0063] According to a seventh aspect of the present invention there is provided a computer readable medium having stored thereon computer program instructions for controlling a computer, or machine controller, or probe controller to perform a method according to the first aspect of the present invention.

[0064] According to another aspect of the present invention there is provided a method of communicating information to a measurement probe attached to a coordinate positioning machine, the method comprising the steps of selecting one or more of a plurality of characteristic movements of the probe in response to the information, controlling the machine to impart movements to the probe, detecting the movements of the probe, and determining or reconstructing information on the probe from the detected movements.

[0065] According to another aspect of the present invention, there is provided a method of communicating with a measurement probe attached to a coordinate positioning machine (with the machine operating under the control of a machine controller), the method comprising the steps of encoding (or representing) information (in the controller) to be communicated to the probe as a sequence of two or more (distinct and / or distinguishable and / or distinctive) movements of (performed by) the probe, controlling (using the controller) the machine to perform (impart the sequences of movements to) the probe, detecting the sequences of movements of the probe, and decoding (or determining) information from the sequences of movements detected in the probe.

[0066] According to another aspect of the present invention, there is provided a method of communicating with a measurement probe attached to a coordinate positioning machine, the method comprising the steps of controlling the machine to perform two or more different (rotational) movement sequences of the probe, and detecting the movement sequences of the probe.

[0067] According to another aspect of the present invention, there is provided a method of communicating with a measurement probe attached to a coordinate positioning machine, the method comprising the steps of representing (encoding) information to be communicated to the probe as a sequence of two or more separate movements of (performed by) the probe, controlling the machine to impart the sequences of movements to (or onto) the probe, detecting the sequence of movements of the probe, and extracting (decoding) information on the probe from the detected sequence of movements.

[0068] According to another aspect of the present invention, there is provided a method of controlling the operation of a measurement probe attached to a coordinate positioning machine, the method comprising the steps of controlling the machine (and thereby communicating with the probe) to perform two or more different sequences of (rotational) movements of the probe, detecting the sequences of movements of the probe, and controlling operation of the probe based on the detected sequences. [Brief explanation of the drawings]

[0069] Reference will now be made, by way of example, to the accompanying drawings in which: [Figure 1] 1 is a schematic diagram of a machine tool embodying the present invention having a drill bit used to perform a machining operation on a workpiece; [Figure 2] FIG. 2 shows the machine tool of FIG. 1 exchanging the drill bit for a measurement probe to perform a measurement operation on a workpiece. [Figure 3] FIG. 3 provides a more detailed illustration of the drill bit in FIGS. 1 and 2. [Figure 4] FIG. 3 provides a more detailed illustration of the measurement probe in FIGS. 1 and 2. [Figure 5] FIG. 1 illustrates schematically a method embodying the invention for communicating information to a measurement probe attached to a coordinate positioning machine; [Figure 6]10A-10C illustrate various possibilities for characteristic movements of the probe that can be used to encode information. [Figure 7] 10A-10C illustrate various possibilities for characteristic movements of the probe that can be used to encode information. [Figure 8] 10A-10C illustrate various possibilities for characteristic movements of the probe that can be used to encode information. [Figure 9] 10A-10C illustrate various possibilities for characteristic movements of the probe that can be used to encode information. [Figure 10] 10A-10C illustrate various possibilities for characteristic movements of the probe that can be used to encode information. [Figure 11] 10A-10C illustrate various possibilities for characteristic movements of the probe that can be used to encode information. [Figure 12] FIG. 1 illustrates how motion can be characterized by cumulative acceleration. [Figure 13] 1 is a flowchart illustrating a method embodying the invention for placing a probe into a configuration loading mode and for communicating configuration data to the probe. [Figure 14] FIG. 10 provides a table showing the various functions of the probe that can be configured in the load configuration mode, along with the possible configuration options available for each function. [Figure 15] FIG. 15 provides a table illustrating a scheme for encoding the configuration data of the functions in FIG. 14 into a series of 9 bits, with different functions each assigned to one or more different bit positions. [Figure 16A] 15 provides tables corresponding to the features in FIG. 14, with each table indicating the bit position value for each possible option associated with that feature. [Figure 16B]15 provides tables corresponding to the features in FIG. 14, with each table indicating the bit position value for each possible option associated with that feature. [Figure 16C] 15 provides tables corresponding to the features in FIG. 14, with each table indicating the bit position value for each possible option associated with that feature. [Figure 16D] 15 provides tables corresponding to the features in FIG. 14, with each table indicating the bit position value for each possible option associated with that feature. [Figure 16E] 15 provides tables corresponding to the features in FIG. 14, with each table indicating the bit position value for each possible option associated with that feature. [Figure 17] 1 is a flow chart illustrating a method embodying the invention for placing a probe into a configuration reading mode and subsequently exiting the configuration reading mode. [Figure 18] 1 is a flowchart illustrating a method embodying the present invention for placing a probe into radio pairing mode. [Figure 19A] FIG. 10 provides a table showing further sequences of characteristic movements that may be performed. [Figure 19B] FIG. 10 provides a table showing further sequences of characteristic movements that may be performed. [Figure 19C] FIG. 10 provides a table showing further sequences of characteristic movements that may be performed. [Figure 20A] FIG. 1 shows probes mounted on vertical and horizontal machine tool spindles, respectively. [Figure 20B] FIG. 1 shows probes mounted on vertical and horizontal machine tool spindles, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0070] FIG. 1 is a schematic diagram of a machine tool 1 embodying the present invention, which would typically be installed in a factory or machine shop environment. The machine tool 1 is for performing machining operations on a workpiece 6, which is illustrated in FIG. 1 as being mounted on a base or bed 7 of the machine tool 1. The machine tool 1 includes a spindle 3 to which a drill bit 2 is attached for performing the machining operation on the workpiece 6. The spindle 3 is in turn supported by a support member 4 which is itself moved by a motion system 5, thereby enabling the drill bit 2 to be moved into position to work on the workpiece 6. The motion system 5 will typically provide for movement of the drill bit 2 in three degrees of freedom (along three axes): X, Y, and Z; the spindle 3 is controllable to rapidly rotate about its longitudinal axis R to cause the drill bit 2 to machine features in the workpiece 6.

[0071] The motion system 5 is controlled by a machine controller 10, and these elements are connected via a communication link 11, which is typically a wired connection. Separately, the machine also includes a probe interface 12, which will be described below, and a user interface 14, which is used by an operator to set up and program the machine tool 1 (e.g., the machine controller 10). To the left of the window in the machine tool 1 shown in FIG. 1 is a tool holder or tool rack 8, which is shown to hold a measurement probe 20. After the machine tool 1 has finished working on the workpiece 6, or on a particular feature of the workpiece 6, the machine controller 10 can be used to execute a sequence of movements to effect the drill bit 2, shown in FIG. 1, which is replaced with the measurement probe 20.

[0072] As shown in FIG. 2 , after such a tool change operation to exchange the drill bit 2 for the measurement probe 20, the machine tool 1 can be controlled to perform a measurement operation on the workpiece 6 to inspect the workpiece 6 and verify that any machined features are within tolerance. During the measurement operation, the spindle 3 and attached measurement probe 20 are typically not rotated about their longitudinal axis, as such movement is typically not required or desirable. During the measurement operation, the measurement probe 20 communicates with the probe interface 12 via a separate communication link 13 (e.g., a wireless communication channel or an optical communication channel), for example, to send commands to the probe 20 and / or receive measurement data from the probe 20. That is, this can be considered the measurement probe 20's primary communication channel. Following the measurement operation, if there is further work to be performed on the workpiece 6, the measurement probe 20 can be exchanged for the drill bit 2 (or some other tool held in the tool rack 8) for further machining or processing operations.

[0073] FIG. 3 provides a more detailed view of the drill bit 2 in FIGS. 1 and 2 , particularly showing the shank 9 adapted to couple with the spindle 3 of the machine tool 1 using a standard removable shank connector. The longitudinal axis of rotation R is also shown in FIG. 3 . FIG. 4 provides a more detailed view of the measurement probe 20 in FIGS. 1 and 2 , which also has a shank 29 adapted to similarly couple with the spindle 3 of the machine tool 1 using a standard removable shank connector. As noted above, the probe 20 does not typically rotate during normal use (e.g., during a measurement operation), but the longitudinal axis of rotation R is also shown in FIG. 4 for further relevance in describing a method of transmitting information embodying the present invention. The measurement probe 20 illustrated in FIG. 4 is battery-powered, and therefore also includes a battery compartment 24 into which a battery can be inserted. The measurement probe 20 in this example is a touch-trigger probe and, therefore, includes a stylus 22 that contacts the workpiece. Finally, measurement probe 20 has an annular window 26 through which optical signals can be transmitted and received to and from probe interface 12 via wireless communication link 13 illustrated in FIG. 2 . This can be considered the primary communication channel for probe 20. Elements illustrated schematically within window 26 are optical transmitters and receivers, and associated exposed electronic components. Also illustrated schematically in FIG. 4 is probe 20 one or more motion sensors 21 for sensing motion imparted to measurement probe 20 by machine 1, and a controller 25 for determining whether the sensed motion includes one or more of a plurality of characteristic motions and, in response, performing an action on or controlling the operation of probe 20.

[0074] Figure 5 is a schematic diagram of a method embodying the invention generally for communicating information to a measurement probe (such as measurement probe 20 of Figures 1 and 2) attached to a coordinate positioning machine (such as machine tool 1 of Figures 1 and 2). More specific embodiments will be described further below.

[0075] In step S1, as described above, the measurement probe 20 is attached to the spindle 3 of the machine tool 1. In step S2, it is determined what information is to be communicated to the measurement probe 20. As will be described in more detail below, this information may be configuration data for the measurement probe 20, or commands to put the measurement probe 20 into a particular mode of operation, or indeed any arbitrary information.

[0076] In step S3, the information is encoded as one or more of a plurality of characteristic movements of the probe 20. For example, there may be a look-up table containing a plurality of different characteristic movements of the probe 20, and step S3 would involve selecting one or more of those characteristic movements based on the information to be transmitted. In this manner, the selected characteristic movement becomes a representation of the information to be transmitted. This will become more apparent in specific embodiments described below.

[0077] In step S4, the machine tool 1 is controlled to impart the movement determined in step S4 to the probe 20, for example by using the movement system 5 and / or by rotating the spindle 3 about the rotation axis R, as described above with reference to Figures 1 to 4.

[0078] In step S5, these movements are detected in the probe 20 by the movement sensor 21, and in step S6, information is decoded or extracted by the probe controller 25 of the probe 20 from the movements detected in step S5. Upon decoding the information transmitted by the machine controller 10 from these movements, the decoded information is used appropriately in the probe 20 (based on what the information represents) to control some aspect of the operation of the probe, for example if the information represents configuration data or a command intended to change the operating mode of the probe 20.

[0079] Finally, step S8 represents the measurement probe 20 communicating with the probe interface 12 using the primary communication channel 13, e.g., configuring, establishing, or initiating this primary communication channel 13 using the methods of steps S1 to S7.

[0080] Various possibilities for characteristic motions of probe 20 will now be described with reference to Figures 6-11. Each of the multiple possible characteristic motions must be distinguishable by probe 20 from each of the other characteristic motions. For example, Figure 6 shows a sequence of rotational motions performed by probe 20, each of which is clockwise for the same duration, but at a different rotational speed. As such, each of these motions can be described as a characteristic motion because it is distinguishable from each of the other motions by its rotational speed, which is detectable in probe 20 by an appropriate motion sensor. A characteristic motion in this context can be considered to be an individual one of the rotational motions in Figure 6, or a combination of motions (e.g., a symbolic sequence consisting of all five rotations shown in Figure 6, their order, and their rotational speeds).

[0081] 7 shows different sequences of rotational movements performed by probe 20, each in a clockwise direction, but of varying duration and rotational speed. As such, each of these movements (or combinations of such movements) can be described as a distinctive movement, since each movement is distinguishable from the others by both duration and rotational speed, both of which are measurable in probe 20.

[0082] 8 shows another sequence of rotational movements performed by probe 20, each at the same rotational speed but in different directions (some clockwise, some counterclockwise) and of different durations. As such, each of these movements (or combinations of such movements) can be described as a distinctive movement, since each movement is distinguishable from the others by both duration and rotational direction, both of which are measurable by probe 20.

[0083] 9 shows another sequence of rotational movements performed by probe 20 at various respective rotational speeds, directions, and durations. As such, each of these movements (or combinations of such movements) can be described as a distinctive movement, since each movement is distinguishable from the others by its rotational speed, direction, and duration, and all of these movements are measurable at probe 20.

[0084] The characteristic motion can also be a rotational motion combined with a translational motion of the probe 20, as illustrated in Figures 10 and 11. In Figure 10, a counterclockwise rotation combined with a Z-direction motion (acceleration) (in either direction) is used to encode the information bit "0," while in Figure 11, a clockwise rotation combined with a Z-direction motion (in either direction) is used to encode the information bit "1." In this way, a sequence of such characteristic motions can be used to convey a series of logical bits, which can be used to represent any data that needs to be conveyed to the probe 20. The bit periods can be of fixed duration or separated by null periods of zero movement.

[0085] The motion of the probe 20 can also be characterized, at least in part, by its linear acceleration and / or rotational acceleration (as opposed to its linear speed and / or rotational speed). For example, considering the Z-direction motion in FIGS. 10 and 11, this Z-direction motion could be characterized by its linear acceleration rather than its linear velocity. Machine motion in the Z direction (imposed on the probe 20) would actually consist of an acceleration phase followed by a deceleration phase, as shown in FIG. 12(a). It is not practical for the machine tool 1 to provide high acceleration for extended periods of time, as the speed of the accelerated machine components (including the probe 20) would become too large. One possible implementation would be to take the absolute output of a linear accelerometer for the Z axis, as shown in FIG. 12(b), and derive a cumulative or accumulated acceleration for each bit period, as shown in FIG. 12(c). When the cumulative acceleration in Fig. 12(c) reaches a predetermined threshold (as marked in Fig. 12(c)), the movement is determined to be a characteristic Z-motion in the situation of Figs. 10 and 11. In this way, high acceleration of the mechanical components can be avoided.

[0086] In each of the examples shown in Figures 6 to 11, angular velocity (rotation) modulation is used to characterize various movements in the probe 20. For the examples shown in Figures 10 and 11, angular velocity (rotation) modulation is combined with linear acceleration (in the Z direction) modulation.

[0087] In summary, the movement, or each of the movements, performed by the probe 20 is: (a) The magnitude of acceleration, (b) direction of acceleration, (c) speed of movement, (d) direction of movement; (e) duration of the movement; (f) timing of movements, and (g) The order of movements within a movement sequence The movement may include rotational and / or translational movement.

[0088] The characteristic motion should also preferably be easily distinguishable by the probe 20 from other motions undertaken by the probe 20 during normal operation, such as translational motion around the working envelope of the machine tool 1. For this reason, it is preferred to use rotation about the longitudinal axis R of the probe 20 to form at least part of the characteristic motion, as this is not the type of motion that would normally be imparted to the probe 20 during normal operational use (except in certain circumstances, such as for measurement cycles where the probe 20 may rotate to accommodate stylus runout). However, this is not essential, as long as the motion is in some way distinguishable from normal operational motion. Because some machine tools move the machine table 7 (and workpiece 6) in the X and Y directions, rather than the support member 4, with the motion system 5 only moving the support member 4 (and spindle 3) in the Z direction, a Z movement (or acceleration) was chosen for the characteristic movement shown in Figures 10 and 11, and this idea would ideally work consistently on multiple machine tools 1 with different acceleration profiles, so complex symbols would not be possible. However, it is also possible to use translational movement or translational acceleration in the X and Y directions, where appropriate, to characterize (at least in part) the characteristic movement of the probe 20.

[0089] In a simple case, performing one or more characteristic movements described above for the probe 20 can be used to initiate a single corresponding function in the probe, such as switching the probe 20 into a different operating mode, and multiple different operating modes can be selected by using different characteristic movements to communicate different respective commands to the probe 20. For example, a user manual for the measurement probe 20 might instruct to rotate the probe 20 at 600 rpm (revolutions per minute) for 20 seconds to enter mode A, rotate the probe 20 at 1200 rpm for 20 seconds for mode B, or rotate the probe 20 at 1200 rpm for 40 seconds for mode C. The user would then enter (using the interface 14) a line of code (or rate variable / duration variable pair) for the desired mode (A, B, or C) into the machine controller 10, which would instruct the machine tool 1 to rotate the probe 20 at the predetermined speed for a predetermined duration. In this way, information in the form of a command to change the operating mode of the probe 20 is communicated to the probe 20 by encoding the information in the form of a characteristic rotational movement of the probe 20 (which is simply a rotational movement, but it should be noted that this is one of many possible rotational movements that the probe 20 can be made to perform), which is detected and decoded at the probe 20 to affect a change in the operating mode of the probe 20.

[0090] It is also possible to use a predetermined characteristic motion, or sequence of characteristic motions, for example one or more characteristic rotations, to place the probe 20 in a "receptive" mode, while one or more further characteristic motions of the probe 20 (such as rotations and / or accelerations) are used to encode and transmit data to the probe 20, which data is detected and decoded by the probe 20 for use by the probe 20 in some manner. This possibility is illustrated by the flow chart of Figure 13, where the "receptive" mode is a configuration load mode, in which various configuration options are loaded into the probe 20.

[0091] 13, step T1 determines the characteristic motions required to place the probe 20 in a configuration loading mode. In other words, in step T1, a command to place the probe 20 in a configuration loading mode is encoded into one or more characteristic motions to be performed by the probe 20. A user may look up the corresponding characteristic motions in a user manual, and the encoded motions may be programmed into the machine controller 10 via the interface 14. Alternatively, the user may directly indicate via the interface 14 that a configuration loading mode is required for the probe 20, and the controller 10 may perform a lookup to determine the corresponding characteristic motions to be performed by the probe 20 in order to communicate the "configuration loading mode" command (encoded information) to the probe 20.

[0092] In step T2, the machine tool 1 is controlled to impart the movements determined in step T1 to the probe 20, for example by using the motion system 5 and / or by rotating the spindle 3 about its axis of rotation R, as described above with reference to Figures 1 to 4. In step T3, these movements are detected in the probe 20 by the movement sensor 21, and from these detected movements the probe controller 25 determines that the probe 20 has been commanded to enter configuration read mode (decoded information). Accordingly, in step T4 the probe controller 25 puts the probe 20 into configuration read mode.

[0093] In step T5, it is determined what probe configuration data should be communicated to the probe 20. For example, if the probe 20 is an optical probe (such as the example shown in FIG. 4, having a primary communication channel 13 that is optically based as shown in FIG. 2), one such configuration option might relate to the "Switch On Method" to be used for the optical channel 13, and another might be for the "Switch Off Method" to be used. Other features controlled by configuration options might be "Enhanced Trigger Filter and Spindle Orientation capability," "Optical Transmission Type," and "Optical Power Setting." These features, along with the possible configuration options available for each feature, are summarized in the table in FIG. 14. For example, the "Switch On Method" can be either "Optical On (Standard)" or "Optical On (3 Second Delay)", while the "Switch Off Method" can be one of "Optical Off", "Short Timeout (12 Seconds)", "Medium Timeout (22 Seconds)", and "Long Timeout (134 Seconds)".

[0094] In step T6, the probe configuration data determined in step T5 is encoded into one or more of a plurality of characteristic probe movements. Referring to the table in FIG. 14, the "switch-on" function has two possibilities, so it can be encoded into a single information bit with a value of "0" or "1" depending on the desired configuration selection for that function. Similarly, the "switch-off" function has four possibilities, so it can be encoded into two information bits with values ​​of "00," "01," "10," or "11" depending on the desired configuration selection for that function. A similar approach can be taken for the other functions shown in FIG. 14, and the configuration options for all five functions in FIG. 14 can be encoded into nine information bits, as shown in the table in FIG. 15. FIGS. 16A-16E provide tables corresponding to the functions in FIG. 14, each showing bit position values ​​for each possible configuration option associated with that function.

[0095] For each of the information bit numbers 0 to 8 (#0 to #8) shown in the table in Figure 15, the characteristic probe movement as shown in Figure 10 can be used to convey a value of "0" and the characteristic probe movement as shown in Figure 11 can be used to convey a value of "1". This provides a scheme (or algorithm) for encoding configuration data into the characteristic probe movement. For example, if probe 20 needs to be configured: (a) Optical on (3 s delay); (b) Medium timeout (22 seconds); (c) Automatic reset on / filter on (16ms), (d) Conventional (filter-on start), and (e) Low Power. Using the "lookup table" in Figures 16A to 16E, this configuration information would be encoded into a bit sequence of "1_10_011_01_0" (or simply "110011010" without delimiters), with each of these bit values ​​having an associated characteristic probe behavior (depending on whether the bit value is "0" or "1") as shown in either Figures 10 and 11.

[0096] In step T7, the machine tool 1 is controlled to impart the movements determined in step T6 to the probe 20, but for this machine tool, the probe movements in Figures 10 and 11 will require a combination of accelerating the probe 20 in the Z direction using the motion system 5 and rotating the spindle 3 (to which the probe 20 is attached) about the rotation axis R. In step T8, these movements are detected in the probe 20 by the motion sensor 21 and decoded by the probe controller 25 to extract the configuration data transmitted by the machine 1. In step T9, the probe 20 is configured according to the decoded configuration data from step T8. Finally, in step T10, the configuration read mode is terminated by communicating a further command to the probe 20, which command (information) is encoded as one or more movements of the probe 20 (each selected from a plurality of different characteristic movements) in a manner similar to that described above. Alternatively, the configuration read mode can be terminated automatically after a predetermined time has elapsed.

[0097] FIG. 17 is a flowchart illustrating a method embodying the present invention for placing a probe in a configuration read mode and subsequently exiting the configuration read mode. As the name implies, this mode is for reading the current configuration from the probe 20 (as opposed to the method in FIG. 13, which is for writing a new configuration to the probe 20). Because this is similar to the previous embodiment, only a brief description is required. In step P1, a command (a type of information) for placing the probe 20 in the configuration read mode is encoded into one or more movements of the probe 20 (each selected from a plurality of different characteristic movements). In step P2, the machine tool 1 is controlled to impart the movements determined in step P1 to the probe 20, and in step P3, these movements are detected and decoded in the probe 20 by the movement sensor 21 to recover the command sent from the machine controller 10. In response to receiving the command, in step P4, the probe controller 25 places the probe 20 in the configuration read mode. To this end, in step P5, current configuration data for the probe 20 is communicated to the probe interface 12 of the machine 1 via the primary communications (e.g., wireless) channel 13 (see Figure 2). This configuration data may be communicated via a sequence of trigger pulses through the SKIP input. (Many modern controllers include a direct input for the probe's trigger signal, often called a SKIP input, in which case the probe's trigger signal is effectively read immediately and the current axis positions are "latched" upon receipt of this signal.) Then, in steps P7-P10, a command is encoded and communicated from the machine 1 to the probe 20 (where it is decoded and pursued) to exit the configuration data read mode and return the probe 20 to standby mode.

[0098] FIG. 18 is a flowchart illustrating a method embodying the present invention for placing a probe in radio pairing mode. This method is intended to address the problem of a probe 20 being paired to a probe interface 12 on a particular machine tool 1 and then being moved to an adjacent machine tool 1, particularly in a factory with many machine tools 1 in a relatively small space. In this situation, the original probe interface 12 may be able to communicate with the probe 20 after it has been moved to the new machine tool 1. This could result in a situation where the probe interface 20 receives, for example, a seated status from the probe 20, regardless of whether the probe 20 in its spindle 3 is actually in contact with the workpiece 6, which could potentially lead to a machine crash (if the motion system 5 drives the probe 20 into the workpiece 6, causing damage to the probe 20 and / or other components of the machine tool 1).

[0099] To overcome the above problem, machine tool 1 performs a probing move in step Q1. If no trigger signal is received back from probe 20 before the machine reaches the target position (by which point a trigger signal would be expected to have been received), then it can be assumed that the scenario described above may be occurring. In this case, machine tool 1 proceeds to the subsequent steps shown in FIG. 18, where a sequence of rotations with different speeds and directions is performed to force probe 20 in its spindle 3 into an "acquisition" state (or wireless pairing mode). This is accomplished in a similar manner to that described above, with commands encoded into a characteristic probe movement sequence in step Q2, probe 20 moved accordingly in step Q3, and the probe 20 movement detected and decoded in step Q4. In response to the received command, probe 20 is placed into wireless pairing mode in step Q5. At the same time, the wireless interface 12 is also placed into a captured state (or wireless pairing mode) in step Q6, for example, through the use of a sequence of probe start input pulses. Using wireless pairing routines performed by the probe 20 and wireless interface 12 in steps Q7 and Q8, respectively, the machine tool 1 can "re-pair" with the probe 20 present in its own spindle 3, thereby overcoming the problem described above of an erroneous seated signal. In steps Q9 through Q11, a command is encoded and communicated to the probe 20 (again using one or more probe movements to encode and communicate the command to the probe 20) to exit wireless pairing mode and return the probe 20 to standby mode.

[0100] The various functions and sequences described above can be combined in very flexible ways. For example, rather than combining them into a single motion, such as a “wake up” command and a separate “message” command (i.e., where “wake up” and “message” are part of the same motion), it may be more practical (e.g., better for power management) to have two stages in the sequence. Figures 19A-19C show additional sequences of characteristic motions that may be performed in different scenarios; of course, with the flexibility provided by the proposed communication method, countless other possibilities exist as well. In Figures 19A-19C, “CW” and “ANTI” represent clockwise and counterclockwise rotation of the probe 20, respectively, at any rotational speed, unless otherwise specified. If the rotation direction is not specified (e.g., as in Figure 19C), then the rotation direction does not matter (and instead the motion is characterized by another motion characteristic, such as spin speed and / or duration).

[0101] It is noted that WO 2004 / 090467 also discloses a technique that utilizes probe rotation to switch power-intensive probe circuitry on or off. However, WO 2004 / 090467 only discloses a single command and a single associated characteristic motion. The single command is effectively a "toggle power" command (i.e., switch on if currently off, switch off if currently on), and the single associated characteristic motion is a short, constant-speed rotation in only one direction. There is no suggestion in WO 2004 / 090467 to encode and communicate rich and varied information by expressing information based on multiple different characteristic motions, which is provided by embodiments of the present invention. The method of WO 2004 / 090467 is not adapted to process multiple types of commands. The technique in WO 2004 / 090467 expanded on the technique for switching on a probe described in U.S. Patent No. 4,599,524. In this technique, after the probe is inserted into the machine tool spindle, it is turned on by briefly rotating the spindle, using a centrifugal switch inside the probe to respond to such rotation. After use, the battery can be disconnected by further such rotation or by a delay element within the probe's circuitry that times out after a predetermined period of non-use of the probe.

[0102] Previous implementations of machine tool probes, such as those described in WO 2004 / 090467, utilize centripetal acceleration experienced by an accelerometer attached to the probe as a means of detecting axial rotational velocity when the probe is attached to the machine tool spindle in order to activate the probe from a standby state or deactivate the probe from an operating state. Because the detected centripetal acceleration is independent of rotational direction, the probe can only detect rotation, not direction. According to one embodiment of the present invention, detection of rotational direction (or other characteristic motion) is used as another input to facilitate more complex functions. Additionally, modulation of angular velocity can also be used to convey information to the probe.

[0103] The advent of low-power MEMS (microelectromechanical systems) gyroscopes combined with three-axis accelerometers (so-called Inertial Measurement Units) facilitates the determination of rotation direction in three rotational degrees of freedom (three rotational axes), as well as magnitude. When used in combination with acceleration information in three linear axes, this provides a six-degree-of-freedom measurement. The implementation of the motion sensor 21 will ideally take into account the fact that the probe 20 can be mounted on either a vertical machine tool spindle 3, as shown in FIG. 20A, or a horizontal machine tool spindle 3, as shown in FIG. 20B.

[0104] In addition to encoding or mapping each of a number of different individual commands (or other types of information) to a corresponding set of one or more probe movements, algorithms can also be used to encode continuous variables into appropriate characteristic probe movements. For example, the probe 20 may sense spin or rotational speed and set certain probe parameters (such as a timing filter) based on the measured spin speed. For example, if the rotational speed is measured at 651 rpm, a 6.51 ms filter is set in the probe 20, and if 725 rpm is measured, a 7.25 ms filter is used. In this case, the encoding algorithm used in the machine controller 10 would effectively be R = F × 100, where F is the desired filter duration in milliseconds and R is the rotational speed in revolutions per minute (rpm) for the characteristic probe movement (rotation). The decoding algorithm used in the probe 20 to extract the desired filter duration F from the measured rotational speed R would be the inverse of the encoding algorithm, i.e., F = R / 100.

[0105] It is also clear from the above discussion that information can be encoded as a single motion or as a sequence of motions with many different possible states, e.g., different rotational speeds (rpm) representing different actions. It is also noted that various sequences can be decoded into the same information. For example, three characteristic motions A, B, and C may represent the same information in any order (i.e., ABC is the same as BAC, which is the same as CAB), but different combinations of these motions A, B, and C represent different information (i.e., ABC is different from AAB). It is also possible to encode a first bit and a second bit of information as first and second different characteristic motions, where the first and second characteristic motions are superimposed (performed simultaneously; e.g., a translation in the Z direction provides the first information, and a simultaneous rotation about the Z direction provides the second information).

[0106] Although embodiments of the invention have been described above in relation to machine tools, the same techniques can be used for such probes mounted on other types of coordinate positioning machines. For example, when used with a robotic arm, rotation about one or more rotary joints in the robotic arm can be used to carry out the procedures described above in a completely equivalent manner (to replace the rotation of the spindle 3 about axis R as described above). Since articulated robot arms often include a final rotary joint with an axis of rotation that is axially disposed relative to the arm, this final joint (with the attached probe) can be used in a very similar manner to the rotation of the spindle 3 in the machine tool embodiments described above.

[0107] The machine controller 10 and the probe controller 25 may be dedicated electronic control systems and / or may comprise computers operating under the control of a computer program. For example, the machine controller 10 may comprise a real-time controller for providing low-level instructions to the motion system 5 and a PC for operating the real-time controller. It will be understood that the operation of the coordinate positioning machine 1 may be controlled by a program running on the machine 1, and in particular by a program running on the machine controller 10 as illustrated schematically in FIG. 1. It will also be understood that the operation of the probe 20 may be controlled by a program running on the probe 20, and in particular by a program running on the probe controller 25 as illustrated schematically in FIG. 4. Such a program may be stored on a computer-readable medium or may be embodied in a signal, such as, for example, a downloadable data signal provided from an Internet website. The appended claims should be interpreted as covering the program itself, or a record on a carrier, a signal, or any other form.

Claims

1. 1. A method of transmitting information to a measurement probe attached to a coordinate positioning machine, comprising: encoding the information as one or more of a plurality of characteristic movements of the probe; controlling the machine to impart the movement to the probe; detecting the movement at the probe; decoding information at the probe from the detected movement; A method comprising:

2. 2. The method of claim 1, comprising encoding the information as a sequence of two or more of the plurality of characteristic movements.

3. 3. A method according to claim 1 or 2, characterized in that it comprises the step of performing an action in or controlling the operation of the probe depending on the decoded information.

4. The information is (a) configuration data of the probe; (b) one or more commands, operations, or instructions to be performed by said probe; 4. The method according to claim 1, further comprising at least one of:

5. 5. A method according to any one of claims 1 to 4, comprising the step of using one or more movements as commands to put the probe into a data receiving mode, during which one or more further movements are used to transmit data to the probe.

6. 6. A method according to any one of claims 1 to 5, comprising the step of using one or more movements as commands to put the probe into a data transmission mode, during which the probe communicates data to a machine controller or machine interface.

7. 7. The method of claim 6, wherein the probe communicates the data to the machine controller or machine interface using a sequence of trigger pulses.

8. 8. A method according to any one of claims 5 to 7, wherein the data includes probe configuration data.

9. 9. A method according to claim 8, when dependent on claim 5, comprising the step of configuring the probe using configuration data received at the probe.

10. 10. The method of claim 1, wherein the step of encoding the information comprises selecting one or more movements representing the information from a plurality of predetermined characteristic movements, for example stored in a look-up table or presented in an instruction manual.

11. 11. The method of claim 1, wherein the step of encoding the information comprises converting the information into a corresponding movement or movements performed by the probe using a predetermined algorithm.

12. 12. The method of any one of claims 1 to 11, characterized in that the method is adapted to process two or more types or items of information transmitted to the probe and to encode different types or items of information into different corresponding respective movements of the probe.

13. 13. The method according to any one of claims 1 to 12, characterized in that the one or more movements comprise at least one rotational movement of the probe and / or at least one translational movement of the probe.

14. 14. A method according to claim 13, wherein the or each movement is a rotational movement of the probe.

15. 15. A method according to any one of claims 1 to 14, comprising using at least one movement sensor on the probe to detect the one or more movements and / or distinguish the one or more movements from other movements of the probe.

16. 16. The method of claim 15, wherein the at least one motion sensor comprises at least one accelerometer, for example at least one linear accelerometer.

17. 17. The method of claim 16, comprising using at least two accelerometers on the probe, positioned substantially orthogonal to each other, to detect the movements and / or distinguish them from other movements of the probe.

18. 18. A method according to claim 16 or 17, comprising using at least three accelerometers on the probe, arranged substantially orthogonal to one another, to detect said movements and / or distinguish them from other movements of the probe.

19. The probe is an axial accelerometer for measuring acceleration along an axis of the probe; first and second radial accelerometers for measuring acceleration in first and second substantially orthogonal radial directions, respectively, toward the axis of the probe; 19. The method according to any one of claims 1 to 18, characterized in that it comprises at least one of the following:

20. 20. A method according to any one of claims 1 to 19, wherein the machine is operable to rotate the probe about an axis of rotation of the machine.

21. 21. The method of claim 20, wherein the movement includes at least one rotational movement about an axis of rotation of the machine.

22. 22. A method according to claim 20 or 21, when dependent on claim 19, characterized in that the probe is mounted on the machine substantially aligned with an axis of rotation of the machine.

23. 23. A method according to any one of claims 20 to 22, wherein the machine comprises an articulating probe head to which the probe is mounted, the axis of rotation of the machine being selected from one or more axes of rotation of the probe head.

24. 24. A method according to any one of claims 1 to 23, characterized in that the or each movement is distinguishable by the probe from one another and from other movements performed by the probe.

25. The or each movement is (a) characteristics of said movement, such as its speed and / or duration; (b) the type of movement, such as whether the movement is a clockwise or counterclockwise rotation; (c) the magnitude of the acceleration; (d) the direction of acceleration; (e) the speed or velocity of said movement; and (f) the direction of said movement; and (g) the duration of the movement; (h) the timing of said movement; and (i) the order of the movements within a sequence of movements; (j) a temporal relationship between the movement and one or more other movements in a sequence of movements; 25. The method of claim 1, wherein the movements are characterized by and / or distinguishable (e.g. in the probe) from one another by one or more of:

26. A method according to any one of claims 1 to 25, characterized in that there are a plurality of different movements or combinations of characteristic movements to select from as the movement or movements represented by the information, each corresponding, for example, to a different respective action performed by the probe.

27. 27. A method according to any one of claims 1 to 26, wherein the decoding step performed in the probe is based solely on, or at least takes into account, movements detected in the probe after the probe has been attached to the machine.

28. 28. A method according to any one of the preceding claims, characterized in that the measurement probe is a wireless measurement probe.

29. 29. A method according to any one of claims 1 to 28, characterized in that the measurement probe is alternatively a measurement device such as a measurement probe or a tool setter.

30. 30. A method according to any one of claims 1 to 29, wherein the coordinate positioning machine is a machine tool.

31. 31. Method according to claim 30, when dependent on claim 20, characterized in that the machine axis of rotation is the axis of rotation of the spindle of the machine tool.

32. 31. A method according to claim 30, when dependent on claim 19, characterized in that the probe is mounted on the machine tool such that the axis of the probe is substantially aligned with the spindle axis of the machine tool.

33. 33. The method of any one of claims 1 to 32, wherein the method is for providing a secondary communication means, wherein there is a primary communication means different from the secondary communication means, the primary communication means being used for communication during normal use of the probe, such as for communicating measurement data during measurement operations.

34. 34. The method of claim 33, wherein the primary communication means comprises a wireless communication means, such as optical or radio.

35. 1. A method of controlling a measurement probe attached to a coordinate positioning machine, comprising the steps of: transmitting information to the probe using a method according to any one of claims 1 to 34; performing an action at or controlling the operation of the probe in response to the decoded information; A method comprising:

36. 36. A measurement probe for use in a method according to any one of claims 1 to 35, comprising: the measurement probe is attachable to the machine; at least one movement sensor for sensing movement imparted to the measurement probe by the machine; a controller for determining whether the sensed movement includes one or more of the plurality of characteristic movements of the probe, and for performing an action on or controlling an action of the probe in response to the determination; A measurement probe comprising:

37. A measurement probe or a probe controller, characterized in that it is adapted to use a method according to any one of claims 1 to 35.

38. A machine controller, characterized in that it is adapted to use a method according to any one of claims 1 to 35.

39. 36. A computer program product which, when executed by a computer, machine controller or probe controller, causes the computer, machine controller or probe controller to perform or use a method according to any one of claims 1 to 35.

40. 36. A computer readable medium having stored thereon computer program instructions for controlling a computer, machine controller, or probe controller to perform or use a method according to any one of claims 1 to 35.

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