How the measurement system works

Abstract

The present invention provides a measurement system comprising a coordinate measuring device and a configurable tool rack capable of accommodating multiple stations. [Solution] Stations 105 and 106 hold tools 90 and 95. The measurement system measures a workpiece according to a measurement plan that includes tool changing operations and measurement of the workpiece using various tools available in the rack. The tool changing operations are automatically modified based on a set of operational parameters acquired by electronic devices and sensors installed in the tool rack 100, or in the tool stations, or in the tools in the rack, or in any combination thereof.

Description

Technical Field

[0001] The present invention relates to a method of configuring and operating a coordinate measuring device, and to the arrangement of the coordinate measuring device and measuring tools.

Background Art

[0002] Coordinate measuring machines (CMMs) are known and used in various applications and in various forms in the prior art. Generally, a coordinate measuring device includes a movable positioning platform that can receive various and interchangeable tools and accessories. In measurement, these tools include a coordinate probe, contact probes having various reach distances and various extensions (e.g., contact trigger probes, scanning probes, or analog probes), non-contact probes such as optical probes, vision systems for optical inspection of workpieces, surface condition and roughness probes, and many others. These devices often include a rack for holding multiple tools, and can be programmed to automatically mounted attach and detach the multiple tools one after another according to a measurement program for a specific workpiece. In addition to coordinate measuring devices, industrial robots can also be configured to exchange tools at the work site using such racks. Similarly, metal processing devices can also mounted obtain measurement tools and / or cutting tools from this type of rack.

[0003] The positioning platform where the tool is mounted placed can arbitrarily and automatically change the orientation of the tool. This is common in the field of dimensional measurement, and since the tools are often mounted on an articulated head that operates automatically, they can be oriented as needed for the measurement task.

[0004] To maintain accuracy, it is desirable for the tool to be placed in and removed from the rack in a highly dimensionally accurate, quiet, and reproducible manner so as to avoid impacts and limit the contact force as much as possible. mounted removed.

[0005] European Patent Application EP 4414656 A1 discloses a tool rack for a CMM having a plurality of tool ports on a rail, wherein the position of each port along the rail can be determined and the position can be transmitted to a device controller.

[0006] European Patent EP 3872447 B1 discloses a coordinate measuring device that can automatically determine the position of a tool rack in a measuring space and adjust the tool exchange procedure accordingly.

[0007] U.S. Patent US 8535208 discloses a rack comprising multiple housings for accommodating a set of measuring probes for a coordinate measuring device, and multiple devices for reducing stress during connection and disconnection.

[0008] German utility model DE 9010591 U1 discloses a modular rack having guides capable of supporting a variable number of sliding tool units for a coordinate measuring device.

[0009] European Patent EP 0566719 discloses another modular probe storage unit for a coordinate measuring device. This storage unit includes any number of identical storage ports (each connected to an adjacent storage port).

[0010] A drawback of these known solutions is that when the apparatus is reconfigured to run a new measurement program, the rack must be reconfigured to provide the required tools. The new configuration should be measured and recorded by the controller of the automated apparatus (which is a coordinate measuring device, robot, numerically controlled machine tool, or other automated machine). In a coordinate measuring device, this operation has traditionally been performed by attaching a contact probe to the apparatus and manually guiding the apparatus to sequentially touch predetermined reference points on the tool holders. The positioning of the tool rack within the operating range of the apparatus should conform to the manufacturer's strict specifications. Typically, the rack should be positioned perpendicular to the main axis of the apparatus, and the rails on which the tool stations are mounted should be carefully leveled. Often, non-identical tool holders are required within the tool rack, and their number may vary depending on the required and / or desired number of tools. This adds further complexity to the configuration, as the number of available holders and the precise characteristics and location of each holder should be recorded in the apparatus controller.

[0011] All of these necessary preparations are costly because they involve unproductive time for the equipment and must be performed by skilled workers. Furthermore, they are prone to errors because they involve some manual work. [Overview of the project] [Problems that the invention aims to solve]

[0012] The objective of this invention is to provide an automated system that overcomes the shortcomings and limitations of the prior art. [Means for solving the problem]

[0013] According to the present invention, these objectives are achieved by the features of the appended claims, the method comprising the features of claim 1, and the measurement system of claim 17.

[0014] The dependent claims introduce important and useful technical features and limitations that are not essential to the performance of the present invention. [Brief explanation of the drawing]

[0015] Exemplary embodiments of the present invention are disclosed herein and shown by the drawings. [Figure 1] A schematic diagram of a coordinate measurement system configured to perform the method of the present invention is shown. [Figure 2] Various elements of the above coordinate system and method are shown as functional blocks. [Modes for carrying out the invention]

[0016] Figure 1 shows a simplified coordinate measuring machine (CMM) 200 equipped with a modular tool rack 100 mounted on a reference plane 204. The rack 100 is configurable and can accommodate multiple tool stations 105 capable of holding tools 90 for the coordinate measuring machine.

[0017] This diagram shows only two tool stations to simplify the drawing and improve readability: one tool station 105 with one tool 90, and an empty tool station 106. In a more realistic configuration, the rack 100 may have more tool stations holding multiple tools, and also have spare empty stations for future use. The tool stations do not need to be of a common size or shape. The rack may have tool stations of different shapes, each designed to hold a specific type or kind of tool.

[0018] Advantageously, the modular tool rack 100 can accommodate a variable number of tool stations of various properties in various positions. In this way, the tool rack 100 provides the operator with great flexibility to appropriately configure (and reconfigure) the tool storage area according to planned measurements. The tool rack allows the tool stations to be movably mounted on the tool rack, i.e., by means of slides, screw-in means and / or actuators. That's all. It can be configured to be repositioned manually or automatically along its axis.

[0019] Figure 1 shows a bridge-type CMM, which has a spindle 207 that can move automatically and with high precision along three coordinate axes X, Y, and Z, and a mounting on it that holds measuring instruments and can be directed by rotation around two (or possibly three) rotation axes A and B. like It includes a directional wrist joint 280. This arrangement is common and is described only in this disclosure to illustrate an example of the present invention, but it is not the only possible configuration. The present invention is applicable not only to industrial robots and machine tools, but also to articulated arm coordinate devices, insofar as they are equipped and perform the claimed method.

[0020] The movement of the tool 95 attached to the working end of the CMM is determined and controlled by the CMM controller unit 220. The CMM controller unit 220 operates on the X, Y, Z, A, and B axes of the CMM 200 to measure a workpiece in the accessible measuring space according to a predetermined measurement plan. Often, the measurement plan requires various special tools to perform various operations, and therefore the measurement plan includes tool change operations. The coordinate device has an automatic connector that can connect and disconnect any available tool in the rack 100. The tool change operation in the measurement plan involves approaching the rack, aligning the connector to an empty station 106, leaving the tool at the empty station, moving to a station that holds the selected tool 90, and bringing the tool to the CMM. mountedIt may include steps such as doing something.

[0021] According to an important aspect of the present invention, the tool rack 100 is coupled to a rack controller 120 that communicates with the device controller 220, and a plurality of electronic devices that provide operating parameters (operating parameters of the rack, the tools mounted on the rack, the coordinate device, and the environment). The communication between the rack controller 120 and the electronic devices (which may hereinafter be referred to as "sensors" in the same sense) may be ensured by a (electrical and / or optical) cable 131 in the case of devices 152, 154, for example, or may rely on any suitable form of wireless communication as shown by sensors 164, 162, for example.

[0022] The sensors that communicate with the rack controller are placed on the rack itself, such as sensor 152, for example, on the tool station in the case of sensor 154, for example, on the tool itself as shown for device 162, or may be placed at any position as in the case of camera 158 and sensor 164.

[0023] The nature of the sensors is not limited. Environmental sensors can provide information regarding temperature, humidity, noise, ambient light, the approach of operators or other objects, etc. On the rack, there can be provided various sensors such as occupancy sensors that provide information regarding the presence of tools on a given station, vibration sensors, impact sensors, weight sensors configured to measure the weight of the tool station and determine the mass of the tools mounted thereon, size measuring devices configured to measure the size of the tools on the tool station, and the like.

[0024] The rack of the present invention can be provided with any suitable mechanism for connecting and positioning the tool stations 105, 106. If the positions of the stations are not indexed, the rack or the stations can include a special measuring device that provides the relative position of a given station with respect to the tool rack.

[0025] Sensors attached to tool stations can also take various forms. In important cases, tool stations may include devices configured to determine the dimensions or mass of tools, the presence or type of tools, or the individual identification number of tools present on the station, but any sensors may be attached to tool stations as needed.

[0026] In some cases, such as when the sensor is embedded in the device itself, wireless communication is preferable. This is the case with sensor 162, which could be, for example, a memory providing individual unique part codes to identify the device 90, the model of the device 90, the internal temperature of the device 90, the state of the internal battery, or other important operating parameters.

[0027] The sensor can be placed in any useful location. Sensor 164 may be, for example, a light barrier positioned to output a signal when the CMM head approaches the rack, or a vibration sensor, or a force sensor that measures the force generated during an equipment change operation, or any other sensor.

[0028] When placed within a tool station, electronic devices can be actuators for operating racks, tool stations, and / or probes, and may particularly take the form of electric motors. In some cases, these actuators may be electric motors located within the tool station for locking / unlocking probes from probe heads, for example, by operating a probe locking mechanism. In other cases, these actuators may be configurable for a tool rack. That's all. It may be an electric motor configured to move and / or direct the tool station relative to itself.

[0029] Figure 2 provides a more schematic representation of the components of the measurement system. The device controller 220 and the rack controller 120 are interconnected by a data link 150 capable of transmitting digital information. The two controllers 220 and 120 may be part of a digital data network (e.g., an IP network), in which case the link 150 may be a wired or wireless physical channel capable of supporting IP packets. However, generally, the controllers 120 and 220 can be connected in any way.

[0030] The device controller may be implemented by a personal computer (PC) or industrial PC running a special control program. One of its functions is configured to acquire a measurement plan for a given workpiece by either retrieving it from local storage 224 or the internet 440, or by creating a plan from the nominal type of the workpiece and operator instructions, or by any other method.

[0031] The measurement plan includes a measurement operation, which includes the probe 95 moving on the workpiece, the controller 220 deriving the coordinates of a point on the surface of the workpiece, and the aforementioned tool change operation.

[0032] The device controller 220 has access to an interactive input / output device 235 for reproducing measurement results and / or receiving input and commands from a human operator. The interactive device may be a local device directly connected to the controller 220 (e.g., a monitor, keyboard, mouse) or a remote device connected to another computer that communicates with the controller 220 via a network. The interactive device may also include control lights, control pendants, etc.

[0033] The rack controller 120 communicates with a group of electronic devices 180 configured to provide operating parameters for racks, equipment mounted on the racks, coordinate devices, and the environment, via wired or wireless connections, or, if possible, interface devices not shown.

[0034] As something related to the overall operating parameters of the rack, the electronic device group 180 is: - Collision detector, - Position and / or angle transducers that provide the position and / or orientation of the rack relative to an appropriate coordinate system (e.g., the CMM coordinate system), - A device that provides an indicator of the integrity or wear of the rack (for example, regarding the entire rack) mounted (Counter for the number of attachment / detachment operations), or - A device that provides a state variable that can take values ​​such as "operating," "faulty," or "requires maintenance." It may include.

[0035] Sensors attached to individual equipment stations may include the following: - A device that provides an indicator of the health status or wear of a station (for example, an indicator for an individual tool station) mounted (Counter for the number of attachment / detachment operations), - A device that provides a state variable that can take values ​​such as "operating," "faulty," or "requires maintenance." - Position and / or angle converters that provide the position and / or orientation of the station relative to the tool rack, - Evaluation of the location of equipment within the station (e.g., "empty", "appropriately") mounted "Inappropriately" mounted A device that provides ''. This function can be realized by proximity sensors, optical barriers, microswitches, reed relays, Hall sensors, etc., based on sensing (inductive, capacitive, or optical).

[0036] Sensors can also provide operating parameters for individual tools. Depending on the situation, these sensors may be mounted on the tool station, located remotely (for example, like a camera that takes images of the tool, which are processed by an automatic recognition algorithm), or embedded in the tool itself. Key operating parameters of the tool include the following: - To the station mounted The type or model of the device used (this can be achieved by code reading, RFID tags, image recognition, coded contact, etc.), - To the station mounted The unique part number of each tool (which may be based on the same technology as the type identification device described above), - Integrity or wear status (e.g., wear information obtained by actively moving the instrument within a rack-mounted or near-rack inspection device, such as a start counter, scan distance, or optical control of a ruby ​​touch ball), - Calibration status, - The weight and / or size of the equipment (e.g., obtained by strain gauges in the station or light barriers in the rack), - Battery charge status in applicable locations.

[0037] Several environmental parameters may be obtained. These are: -Temperature - Humidity - vibration - others Includes.

[0038] The list above is not exhaustive.

[0039] The measurement system is used taking operating parameters into consideration. For example, the measurement plan may be modified before its execution based on the operating parameters. Advantageously, the device controller or rack controller ensures that the required tools are in place at a specified time, regardless of their position in the tool rack and / or the tool rack's position in the CMM. mountedThis allows for matching the tools required in the plan with the tools available in the rack, and also enables modification of tool exchange actions in the plan.

[0040] The system is preferably configured to detect a mismatch between the required tools and the available tools, and in this case, to halt program execution, display a warning to the interactive device 235, and preferably suggest corrective action.

[0041] In a modified configuration, the device controller or rack controller may be configured to select available tools in order to distribute wear among multiple equally available tools, or to avoid using tools that are heavily worn or have low battery levels until they are properly maintained or recharged.

[0042] Preferably, especially when the modular tool rack 100 has multiple tool stations of the same shape, the measurement system is also configured to optimize the position of tools in the rack, for example, by moving the most frequently used tools to tool stations closer to the workpiece, while unused, uncalibrated, and worn tools are moved to tool stations further away from the workpiece. Where possible, the program is modified so that this swapping of tools is performed automatically at startup. However, where appropriate, the measurement system may automatically select a desired configuration of the tool rack to optimize the plan and display the desired configuration on the display 235 so that the operator can construct it. In this second semi-automatic variation, the system may also automatically select several configurations that require manual intervention, for example, by requiring changes (or rearrangement) of tool stations. Alternatively or complementary, the measurement system may be configured for 1 of the tool rack and / or tool stations. That's all. The system can instruct a configurable tool rack via an electronic device to automatically achieve a desired configuration (or at least a portion thereof). The system can then verify, using operating parameters, that the desired configuration has been achieved.

[0043] In addition to execution time, optimizing the measurement plan may also take into account other objectives, such as using fewer tools to reduce calibration operations, using more accurate tools (less worn, more recently calibrated or manufactured, at the appropriate temperature) for critical measurements, and preparing tools by pre-powering on or preheating them in preparation for tool changes.

[0044] The measurement system may also propose and plan periodic automatic recalibration (e.g., health checks using special rack functions) during the hidden time of the measurement system and the programmed plan. Alternatively or complementaryly, the measurement system may also be configured to modify the tool change operation so that periodic automatic recalibration can be performed during the (pre-planned) hidden time of the system and / or the programmed plan.

[0045] The rack configuration can be optimized from the standpoint of reducing rack deflection, thereby mounted This improves the reliability of the attachment and detachment operation. The rack may include a deflection detector to help reduce this source of error. Alternatively or additionally, if deflection occurs, it may be compensated for by altering the trajectory of the tool exchange operation.

[0046] Optimization may also aim to avoid collisions. Sensors may also include proximity detectors of various properties (e.g., light barriers, cameras, LIDAR). And the system may detect when a collision is imminent or highly likely to occur. up The proximity detector When showing It may be configured to issue a warning.

[0047] This measurement system may also use the acquired operating parameters to support other functions and / or services, such as calibration of racks and / or tool stations (e.g., using the obtained position and / or orientation of racks and / or tool stations relative to racks in a suitable coordinate system).

[0048] Environmental parameters such as temperature and humidity may be used to correct measurement data, to initiate preventive maintenance, and / or to plan periodic maintenance. [Explanation of Symbols]

[0049] 90 Tools or probes stored in racks Tools or probes equipped at the work end of a 95 CMM 100 racks 105 Station 106 Empty Station 120 Rack Controller 131 Communication link between rack controller and sensor 150 Communication link between the device controller and the rack controller 152 Sensors or electronic devices (e.g., occupancy sensors) 154 Sensors or electronic devices (e.g., vibration sensors) 158 Camera 162 Wireless sensors or electronic devices (e.g., model number) 164 Wireless sensors or electronic devices (e.g., light barriers) 180 Electronic Devices and Sensors 200 CMM 204 Reference plane 207 Z-axis spindle 220 CMM Controller 224 Storage Area 230 Communication link to the interactive console 235 Interactive Console 250 Communication link between the device controller and the CMM 270 CMM XYZ axis motor and position transducer 280 Motor and position transducer for axes ABC of a reorientable wrist joint. 440 Internet, remote servers, and resources

Claims

1. A method for operating a measuring system comprising a coordinate measuring device and a configurable tool rack capable of receiving a plurality of stations, each station capable of holding a tool, - Obtaining a plan for measuring a workpiece using the coordinate measuring device, wherein the plan includes tool changing operations and measurements of the workpiece using various tools available in the tool rack. In a method including, - To acquire a set of operating parameters from one or more electronic devices installed on the equipment rack and / or within the station and / or on the mounted equipment, - Modify the tool exchange operation based on the aforementioned operating parameters, - To carry out the aforementioned plan, The method characterized by including

2. The method according to claim 1, wherein the operating parameters include the position and / or orientation of the tool rack with respect to the coordinate measuring device.

3. The method according to claim 1, wherein the acquisition of the operation parameters is performed by an electronic rack controller, and thereafter the operation parameters are transmitted to the device controller of the coordinate measuring device that performs the plan modification and execution.

4. The method according to claim 1, wherein the operating parameters include the soundness or wear condition of the rack, or the station, or the loaded equipment, and the equipment replacement operation is modified according to the soundness or wear condition of the station or equipment so as to refrain from using an unsound station or equipment, or to distribute wear among the stations or equipment.

5. The method according to claim 1, wherein the operating parameters include one or more of the following: a type identifier for a station or equipment, a unique identifier for a station, a unique identifier for an equipment, the position of the station relative to the equipment rack, the weight of the loaded equipment, and the size of the loaded equipment.

6. The method according to any one of claims 1 to 5, wherein the electronic device includes one or more of the following: a video camera, a strain gauge, an optical barrier, an RFID reader, a position encoder, an angle encoder, an accelerometer, a vibration sensor, an electric actuator, or a motor.

7. The method according to claim 1, wherein the plan is modified during the execution in accordance with changes in the operating parameters.

8. - Automatically select the desired configuration of the rack based on the plan. - To make the desired configuration available to the operator via output peripherals, and / or to instruct the configurable tool rack to operate the desired configuration. - Using the aforementioned operating parameters, confirm that the operator and / or the configurable tool rack have achieved the desired configuration. The method according to claim 1, including the method described in claim 1.

9. The method according to claim 8, wherein the selection of the desired configuration includes an optimization step aimed at reducing bending of the tool rack and / or the execution time of the plan and / or wear of the hardware.

10. The method according to claim 8, wherein the configurable tool rack is configured to receive a variable number of stations and / or a plurality of stations of various types, and the desired configuration includes a desired number of stations, at least one desired type of the stations, and / or a desired relative position and / or orientation of at least one of the stations with respect to the tool rack and / or coordinate measuring device and / or the workpiece.

11. The method according to claim 1, comprising initiating a maintenance operation based on the aforementioned operating parameters.

12. The method according to claim 1, comprising modifying the measurement results based on information regarding vibration, temperature, or humidity included in the operating parameters.

13. The method according to claim 1, comprising receiving a collision signal included in the operating parameters, interrupting the plan, and activating a predetermined collision response.

14. The method according to claim 1, comprising modifying the plan before its execution based on the operating parameters, and / or issuing a warning or prompting corrective action if a mismatch is detected between the operating parameters and the operating parameters necessary to execute the plan.

15. A measurement system comprising a coordinate measuring device equipped with an electronic device controller, and a configurable tool rack capable of receiving a plurality of stations, each station capable of loading tools for the coordinate measuring device, The measurement system comprises an electronic rack controller that communicates with the device controller, which is configured to read operating parameters from a plurality of electronic devices installed on the device rack and / or in the station and / or on the equipment loaded therein, wherein the device controller and the rack controller are programmed to perform the method according to claim 1.

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