Monitoring, detection and control integrated intelligent end effector

Abstract

The invention discloses an intelligent end effector integrating monitoring, detection and control. The intelligent end effector comprises a machining subsystem, a detection subsystem and a monitoring subsystem. A machining subsystem and an electric spindle are used for driving a cutter handle and a cutter to rotate for machining, a detection subsystem is used for providing sound sensation, vision and ultrasonic sensing functions, a sound sensation module collects sound signals in real time and monitors the sound state in the machining process, and a vision module collects machining pictures and analyzes the machining quality. The ultrasonic detection module emits and collects an ultrasonic signal to detect internal damage of a workpiece after machining is completed, and the self-positioning module measures the distance between a cutter and the workpiece to complete self-positioning; the monitoring subsystem is used for sensing dynamic changes of states such as tool abrasion, flutter and machining quality in the machining process through vibration acceleration and vibration displacement sensing, timely early warning is conducted on state abnormity, the state of the machining process is regulated and controlled in real time through the piezoelectric actuator, and efficient and high-quality machining of parts is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent processing, and specifically is an intelligent end effector with multifunctional integrated monitoring, detection and control functions, and involves application in intelligent industrial robots and traditional processing machine tools. Background Art

[0002] With the emergence of various new technologies, the world is moving towards a new height of the fourth industrial revolution. At the same time, the requirements for processing quality and precision are becoming more stringent, and the concept of intelligent manufacturing has been widely mentioned. Intelligent manufacturing requires the production process to be more automated, intelligent, and flexible. Sensors are the basis for realizing intelligent manufacturing, and reasonable sensor layout is crucial. Reasonable sensor selection and integrated layout make process monitoring more accurate and rapid, and at the same time can improve processing efficiency.

[0003] Robots, as the core technology of intelligent manufacturing, have developed rapidly in recent years. As a key component of robots, end effectors have also gained a lot of room for growth. The global market demand for end effectors continues to grow, and end effectors of various functional types emerge in an endless stream. The global end effector market has a strong momentum of development, reaching US$43.9 billion in 2021. End effectors are an important component of robotic systems. They are responsible for converting electrical signals into mechanical motions and are used to perform various tasks, such as assembly and handling. However, the application of end effectors in the processing process has not received widespread attention and research. Using end effectors in processing machine tools or intelligent manufacturing robots can help realize the intelligence and automation of the processing process and improve the processing quality.

[0004] Through the reasonable design of intelligent end-effector, the monitoring, detection and control of the machining process can be integrated. However, the research and application of online monitoring and control technology for efficient and high-quality parts machining processes are not mature enough. Most of them can only reflect the dynamic characteristics of the cutting process through sensor signals, and use this to establish the evaluation and prediction of the milling process and surface quality. There is a lack of functional integration, and there are still problems with the mechanical structure design and sensor layout of the machining end-effector, which requires further research.

[0005] The intelligent end effector designed in the present invention realizes the integration of monitoring, detection and control functions during the processing through the layout of various sensors and the system mechanical structure assembly design, improves the processing accuracy and processing quality, and meets the intelligent needs of intelligent industrial robots and processing machine tools in the automated production process.

[0006] Therefore, it is of great significance to design an intelligent end-effector to realize the integration of monitoring, detection and control during the machining process. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an intelligent end effector that integrates monitoring, detection and control. The device can integrate monitoring, detection and control of processing and improve processing quality.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] An intelligent end effector integrating monitoring, detection and control, including a processing subsystem, a detection subsystem and a monitoring subsystem;

[0010] The machining subsystem includes an electric spindle, which is connected to the monitoring subsystem via an electric spindle fixing frame, connected to the machining platform via a fixture, and connected to the detection subsystem via an upper connecting plate, and the right end is connected to a tool handle for workpiece machining;

[0011] The detection subsystem includes a detection subsystem housing, an acoustic module, a visual module, an ultrasonic detection module and an autonomous positioning module thereof, wherein the acoustic module includes a sound sensor, which is fixed to the inner surface of the detection subsystem housing through a sensor bracket and is used to collect sound signals during processing; the visual module includes an industrial camera and a macro lens, wherein the macro lens is screwed on the industrial camera, and the industrial camera is installed on the inner surface of the detection subsystem housing and is used to collect microscopic images of the surface of the part and detect processing defects of the part; the ultrasonic detection module includes an ultrasonic sensor, which is installed in the sensor outer housing and fixed on a lead screw connecting rod, which is fixed to the detection subsystem housing through a slide table and is used to collect ultrasonic signals; the autonomous positioning module includes a binocular camera, which is fixed to a binocular camera support frame through screws, and the binocular camera support frame is installed on the inner surface of the detection subsystem housing, and the autonomous positioning of the end effector is achieved by measuring the distance between the tool and the workpiece, and the image is collected to evaluate the macroscopic processing dimensional accuracy of the part, including the dimensional accuracy of the drilling diameter and the milling sink;

[0012] The monitoring subsystem includes a vibration acceleration sensing module, a vibration displacement sensing module and a piezoelectric actuation module. The vibration acceleration sensing module includes a three-dimensional vibration acceleration sensor for collecting three-dimensional vibration signals of the electric spindle during processing; the vibration displacement sensing module includes an eddy current displacement sensor, which is fixed in the monitoring subsystem housing along the radial direction of the tool handle, and the probe surface is kept parallel to the tool handle surface, and is used to monitor the radial vibration of the tool during processing; the piezoelectric actuation module includes a piezoelectric ceramic actuator and a piezoelectric gate. The piezoelectric gate presses the piezoelectric ceramic actuator against the monitoring subsystem housing, and the piezoelectric ceramic actuator is used to apply an actuating force to the angular contact ball bearing that is interference fit with the tool handle; there are four piezoelectric actuation modules composed of the piezoelectric ceramic actuator and the piezoelectric gate, which are evenly distributed along the circumference of the tool handle, and the actuating forces in two orthogonal directions are used to offset the radial vibration of the tool during processing to ensure the processing quality.

[0013] Furthermore, when the processing is completed, the control screw connecting rod makes the probe of the ultrasonic sensor contact the surface of the workpiece, and emits and collects ultrasonic signals to determine the internal damage of the workpiece. The ultrasonic sensor is also connected to a force sensor through a spring. The force sensor measures the force signal between the ultrasonic sensor and the workpiece to avoid excessive contact force between the ultrasonic sensor and the surface of the processed part, which may affect the surface quality of the part and damage the ultrasonic sensor.

[0014] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0015] 1. Through the processing subsystem, the electric spindle drives the tool handle and the tool to rotate for processing. The multi-interface bracket connects and fixes the three subsystems. The detection subsystem provides acoustic, visual and ultrasonic sensing functions, wherein the acoustic module collects sound signals in real time to monitor the processing status, the visual module collects processing pictures and analyzes the processing quality, the ultrasonic detection module emits and collects ultrasonic signals after the processing is completed to detect the internal damage of the workpiece, and the autonomous positioning module measures the distance between the tool and the workpiece to complete autonomous positioning; the monitoring subsystem is used to sense the dynamic changes of tool wear, vibration, processing quality and other states during the processing process through vibration acceleration and vibration displacement sensing, and timely warnings are given for abnormal states. The piezoelectric actuator is used to control the processing state in real time to ensure efficient and high-quality processing of parts. The three subsystems work together to achieve integrated monitoring, detection and control of processing.

[0016] 2. The present invention significantly improves the accuracy, reliability and intelligence level during processing; it performs autonomous positioning before processing and autonomously moves to the processing position; it monitors and controls tool vibration during processing, thereby avoiding degradation of processing quality due to tool vibration; it senses the processing status, monitors tool wear, chatter and processing quality, etc., and timely adjusts process parameters to make it work more reasonably; after processing is completed, visual measurement and ultrasonic flaw detection are performed on the workpiece to achieve in-situ measurement and accurate evaluation of processing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the end effector of the present invention;

[0018] Figure 2 It is a schematic diagram of the detection subsystem structure;

[0019] Figure 3 It is a schematic diagram of the monitoring subsystem structure;

[0020] Figure markings: 1-detection subsystem housing, 2-sound sensor, 3-screw connecting rod, 4-tool handle, 5-monitoring subsystem housing, 6-piezoelectric door, 7-electric spindle fixing frame, 8-slide, 9-electric spindle, 10-clamp, 11-machining platform, 12-binocular camera, 13-bracket, 14-industrial camera, 15-upper connecting plate, 16-macro lens, 17-force sensor, 18-spring, 19-ultrasonic sensor, 20-sensor housing, 21-piezoelectric ceramic actuator, 22-unidirectional force sensor, 23-three-directional vibration acceleration sensor, 24-eddy current displacement sensor. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] like Figure 1 As shown in FIG. 1 , it is a schematic diagram of the overall structure of an intelligent end effector with integrated monitoring, detection and control provided by this embodiment, which includes a processing subsystem, a detection subsystem and a monitoring subsystem. Figure 2 , Figure 3 As shown, the detection subsystem and the monitoring subsystem are respectively, which are some specific structures of the intelligent end effector, and the internal structure is described by removing the shell box.

[0023] The intelligent end effector can be installed on a traditional processing machine tool, or it can be connected to the robot's mechanical arm for processing. When the intelligent end effector is connected to the processing machine tool, it is connected to the processing platform 11 through the fixture 10 by a flange; when the intelligent end effector is connected to the robot, the end effector is connected to the parallel collaborative robot through a flange, and the rest of the operations are the same.

[0024] In the machining subsystem, the electric spindle 9 is connected to the machining platform 11 through the electric spindle clamp 10, connected to the monitoring subsystem through the electric spindle fixing frame 7, and connected to the detection subsystem through the upper connecting plate 15. The left and right ends of the electric spindle are connected to the power supply at one end with an aviation plug interface, and connected to the tool handle 4 at the other end to complete the machining. The fixing and clamping mechanism of the electric spindle is mainly composed of parts such as the clamp 10, the electric spindle fixing frame 7, stud bolts and nuts. The clamp 10 is divided into two parts, the upper part and the lower part of the clamp 10 are connected by stud bolts and nuts, which work together to clamp the electric spindle module to prevent vibration. The lower part of the clamp 10 is in contact with the electric spindle fixing frame 7, which is used to clamp and fix the electric spindle 9;

[0025] The detection subsystem includes a detection subsystem shell 1, an acoustic module, a visual module, an ultrasonic detection module and an autonomous positioning module. The visual module includes a macro lens 16 and an industrial camera 14. The macro lens 16 is screwed on the industrial camera 14. The industrial camera 14 is installed in the inner surface of the lower shell of the detection subsystem shell 1. The direction of the macro lens 16 is consistent with the direction of the tool. The main function is to collect and analyze microscopic images of the workpiece after processing and evaluate the processing quality; the acoustic module includes a sound sensor 2, which is fixed on the surface of the detection subsystem shell 1 through a transmitting sensor bracket 13 and is used to collect sound signals during processing; the autonomous positioning subsystem includes a binocular camera 12. The binocular camera 12 is fixed on the binocular camera support frame by screws, and the binocular camera 12 is installed on the outer surface of the detection subsystem housing 1 by a bolt structure. It is used to measure the distance between the tool and the workpiece for autonomous positioning, and can measure the size of the workpiece. After the processing is completed, the image of the part is collected for processing quality analysis; the ultrasonic detection module includes an ultrasonic sensor 19, and the ultrasonic sensor 19 is installed in the sensor outer shell 20 and fixed on the lead screw connecting rod 3. The lead screw connecting rod 3 is fixed in the detection subsystem housing 1 through the slide 8. The main transmission components of the slide 8 are the lead screw and the servo motor. The rotation of the motor drives the lead screw to move horizontally, and the lead screw connecting rod 3 also moves horizontally. When the processing is completed, the lead screw is controlled to move to contact the probe of the ultrasonic sensor 19 with the surface of the workpiece, and the ultrasonic signal is emitted and collected to determine the internal damage of the workpiece. At the same time, the force sensor 17 connected to the ultrasonic sensor 19 by the spring 18 measures the force signal between the ultrasonic sensor 19 and the workpiece to avoid excessive contact force between the ultrasonic sensor 19 and the surface of the processed part, which affects the surface quality of the part processing and damages the ultrasonic sensor;

[0026] The monitoring subsystem includes a vibration acceleration sensing module, a vibration displacement sensing module and a piezoelectric actuation module. The vibration acceleration sensing module includes a three-dimensional vibration acceleration sensor 23, which is clamped on the monitoring subsystem housing 5 and is used to collect three-dimensional vibration signals of the electric spindle during processing; the vibration displacement sensing module includes an eddy current displacement sensor 24, wherein the eddy current displacement sensor 24 is radially fixed in the monitoring subsystem housing 5, and the probe surface is kept parallel to the surface of the tool handle, and is used to monitor the vibration of the tool during processing;

[0027] The piezoelectric actuation module includes a piezoelectric ceramic actuator 21 and a piezoelectric gate 6. The piezoelectric ceramic actuator 21 is pressed against the surface of the tool handle by four piezoelectric gates 6 evenly distributed on the surface of the monitoring subsystem housing 5. The piezoelectric ceramic actuator is used to apply actuation force to the angular contact ball bearing that is interference-fitted with the tool handle to suppress tool vibration. A unidirectional force sensor 22 is installed on the right side of the piezoelectric ceramic actuator 21 to collect the axial force signal of the tool handle during processing. The four piezoelectric gates 6 are evenly distributed along the circumference of the tool handle, and the actuation forces in two orthogonal directions are used to offset the radial vibration of the tool during processing to ensure processing quality.

[0028] Specifically, the intelligent end effector can be installed on traditional processing machine tools and robots. When in use, the intelligent end effector of the present invention is first installed on the processing platform. The rear end of the end effector is connected to the power supply, and the front end is connected to the tool to process parts. The electric spindle 9 is fixed in the fixture 10, and the fixture 10 is connected to the electric spindle fixing frame 7 through a flange connection and then connected and fixed to the processing platform 11.

[0029] Before the intelligent end effector mills the surface of a part, it must first clamp the parts or blank materials to be processed in the appropriate position in front of the tool, maintain an appropriate distance, and then control the robotic arm or the processing platform of the traditional horizontal milling machine to make fine adjustments. Finally, the binocular camera 12 is used to autonomously locate the tool and the intelligent end effector itself, and the information collected by the binocular camera 12 is located through programming calculation, and the posture or distance from the workpiece is automatically adjusted. After adjusting its own posture and positioning its own coordinates, the intelligent end effector measures the size of the workpiece through the binocular camera 12, adjusts the angle between the tool in front of the motor and the workpiece surface, ensures that the tool feed direction during processing is the same as the actual processing direction, ensures the accuracy of the processing route, and prevents the intelligent end effector from processing the parts incorrectly due to the feed path error during processing, which seriously affects the processing quality and processing accuracy. When processing large parts or parts with irregular surfaces, the parts cannot be clamped on the traditional horizontal milling machine. The end effector is also connected to the parallel collaborative robot at the lower end of the fixture 10 through a flange in the same way as the horizontal milling machine ( Figure 1The figure in the figure shows the clamping form of a horizontal milling machine). Since the parallel collaborative robot has multiple degrees of freedom and is easy to move, the parallel collaborative robot is moved to the processing part at a suitable position away from the electric spindle. The position of the end effector itself is also located, monitored and adjusted by compiling a CNC program. The rest of the process is the same as the traditional horizontal machine tool processing method.

[0030] After adjusting the coordinates and posture of the intelligent end effector and determining the processing route, the processing and production process officially begins. At the beginning of work, the horizontal milling machine feed platform drives the intelligent end effector. After the tool in front of the electric spindle 9 approaches the initial processing point of the component, the electric spindle 9 starts to work, and the high-speed rotation drives the tool handle to rotate, thereby driving the tool, and the actual production and processing begins. During the process of tool processing parts, the sound sensor monitors whether there is any abnormal sound during the production and processing, receives the sound signal and analyzes the processing status in real time. If there is an abnormal sound, it is fed back to the back end, and the three-way vibration acceleration sensor 23 collects the vibration signal. The back end performs effective data processing on the collected sound signal and vibration signal to change the tool position or the electric spindle speed to ensure effective processing and achieve stable tool feeding processing. The surface of the eddy current displacement sensor probe is parallel to the surface of the tool handle, measures the radial vibration of the tool, and transmits the collected vibration signal to the back end. After calculation, the back end controls the movement of the tool handle through the piezoelectric ceramic brake to reduce the degradation of processing quality caused by tool vibration.

[0031] When the processing is completed, the end effector returns to the original coordinate position, the lead screw motor starts working, and the lead screw feeds forward, so that the ultrasonic sensor fits the workpiece to detect internal damage to the processed parts. The force sensor located at the rear end of the ultrasonic sensor measures the force signal between the ultrasonic sensor and the workpiece to avoid excessive extrusion, damage to the sensor and affect the surface processing quality of the workpiece. At the same time, the industrial macro camera stretching lens located in the processing detection module, its microscope lens performs microscopic processing quality inspection on the surface of the milled parts, and the binocular camera collects the image of the parts after processing to detect the macroscopic processing quality of the parts.

[0032] After the inspection, the lead screw retracts to its original position, and all the data obtained in the early stage is transmitted to the back-end for analysis to evaluate whether the processing requirements are met and whether fine processing such as fine turning is required. If not, that is, the processing quality meets the standards, the results are displayed, the processed parts are disassembled, and the processing work is completed.

[0033] The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solution of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the scope of the present invention and the scope of protection of the claims, a person of ordinary skill in the art can also make many forms of specific changes under the guidance of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. An intelligent end effector integrating monitoring, detection and control, characterized in that: Including processing subsystem, detection subsystem and monitoring subsystem; The processing subsystem comprises an electric spindle (9), the electric spindle (9) is connected to the monitoring subsystem via an electric spindle fixing frame (7), is connected to the processing platform (11) via a fixture (10), and is connected to the detection subsystem via an upper connecting plate (15); the right end of the processing subsystem is connected to a tool handle for processing a workpiece; The detection subsystem comprises a detection subsystem housing (1), an acoustic module, a visual module, an ultrasonic detection module and an autonomous positioning module thereof, wherein the acoustic module comprises a sound sensor (2), the sound sensor (2) being fixed to the inner surface of the detection subsystem housing (1) via a sensor bracket (13) and being used to collect sound signals during processing; the visual module comprises an industrial camera (14) and a macro lens (16), the macro lens (16) being screwed onto the industrial camera (14), the industrial camera (14) being mounted on the inner surface of the detection subsystem housing (1) and being used to collect microscopic images of the surface of a part and detect defects in the processing of the part; the ultrasonic detection module comprises An ultrasonic sensor (19), the ultrasonic sensor (19) is installed in a sensor housing (20) and fixed on a lead screw connecting rod (3), the lead screw connecting rod (3) is fixed on a detection subsystem housing (1) via a slide (8), and is used to collect ultrasonic signals; the autonomous positioning module includes a binocular camera (12), the binocular camera (12) is fixed on a binocular camera support frame via screws, the binocular camera support frame is installed on the inner surface of the detection subsystem housing (1), and the autonomous positioning of the end effector is achieved by measuring the distance between the tool and the workpiece, and images are collected to evaluate the macroscopic processing dimensional accuracy of the parts, including the dimensional accuracy of the drilling diameter and the milling sink; The monitoring subsystem comprises a vibration acceleration sensing module, a vibration displacement sensing module and a piezoelectric actuation module. The vibration acceleration sensing module comprises a three-dimensional vibration acceleration sensor (23) for collecting three-dimensional vibration signals of the electric spindle (9) during machining. The vibration displacement sensing module comprises an eddy current displacement sensor (24). The eddy current displacement sensor (24) is fixed in the monitoring subsystem housing (5) along the radial direction of the tool handle, and the probe surface is kept parallel to the tool handle surface, so as to monitor the radial vibration of the tool during machining. The piezoelectric actuation module comprises a piezoelectric ceramic actuator (21) and a piezoelectric gate (6). The piezoelectric gate (6) presses the piezoelectric ceramic actuator (21) against the monitoring subsystem housing (5). The piezoelectric ceramic actuator (21) is used to apply an actuating force to an angular contact ball bearing that is interference-fitted with the tool handle. There are four piezoelectric actuation modules composed of the piezoelectric ceramic actuator (21) and the piezoelectric gate (6), which are evenly distributed along the circumference of the tool handle. The actuating forces in two orthogonal directions are used to offset the radial vibration of the tool during the machining process, thereby ensuring the machining quality.

2. According to claim 1, the intelligent end effector integrating monitoring, detection and control is characterized in that: When the processing is completed, the control screw connecting rod (3) makes the probe of the ultrasonic sensor (19) contact the surface of the workpiece, and then emits and collects ultrasonic signals to determine the internal damage of the workpiece. The ultrasonic sensor (19) is also connected to the force sensor (17) through the spring (18). The force sensor (17) measures the force signal between the ultrasonic sensor (19) and the workpiece to avoid excessive contact force between the ultrasonic sensor (19) and the surface of the processed part, which may affect the surface quality of the part and damage the ultrasonic sensor.

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