Robot control system

Abstract

It enables stable operation at fixed points and highly accurate automated operation. [Solution] The robot control system according to the present invention comprises a trolley configured to move along rails, a robot mounted on the trolley, and a control device that controls the movement of the trolley and the work operations of the robot. The control device moves the trolley toward at least one of a plurality of predetermined fixed points, stops the trolley at the fixed point, stores movement operation information and work operation information in association with each other to cause the robot to perform a work operation at the stopping position, and sequentially executes the movement of the trolley and the work operations of the robot based on the stored information.

Description

Technical Field

[0001] The present invention relates to an industrial automation system, and in particular, to a robot control system for controlling the positional movement and work operations of a robot mounted on a carriage movable along a rail. More specifically, the present invention relates to a mobile robot that autonomously performs work based on predetermined fixed point positions.

Background Art

[0002] In recent years, articulated robots and mobile robots have been actively introduced at manufacturing sites, inspection lines and the like for the purpose of labor saving and automation. For example, Patent Document 1 discloses a technique related to the joint structure of a robot, and presents findings on downsizing of movable parts and detachability. Further, Patent Document 2 discloses an operation control method for a personal assistance robot based on environmental sensing, in which output processing corresponding to the surrounding situation of a user is performed. Furthermore, Patent Document 3 discloses a load detection type robot platform for collaborative work with humans, which is characterized by force detection and cooperative operation.

[0003] However, these techniques are insufficient for the configuration for performing work with high repeatability at a specific fixed point, and problems remain with regard to integrated control of movement and work, and coordination with a mechanical fixing mechanism for fixed points.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventional robot control systems had the following problems:

[0006] The accuracy of robot operations decreases due to misalignment with the workpiece. The stopping position of the trolley varies slightly each time, making the setup process complicated. Vibrations and shocks between the trolley and the rails can cause the robot's movement accuracy to become unstable. The management of work procedures and stopping positions relies on manual processes, resulting in a lack of reproducibility.

[0007] The objective of this invention is to solve these problems and achieve stable operation at a fixed point and highly accurate automated operation. [Means for solving the problem]

[0008] The robot control system according to the present invention comprises a trolley configured to move along rails, a robot mounted on the trolley, and a control device that controls the movement of the trolley and the work operations of the robot, wherein the control device moves the trolley toward at least one of a plurality of predetermined fixed points, stops the trolley at the fixed point, stores movement operation information and work operation information in association with each other for causing the robot to perform a work operation at the stopping position, and sequentially executes the movement of the trolley and the work operations of the robot based on the stored information.

[0009] Furthermore, the rail and the trolley are each equipped with a locking mechanism for physically fixing the trolley at two or more predetermined fixed positions, and the locking mechanism fixes the trolley at the fixed position by the engagement of the locking portion of the trolley with the engaging portion of the rail.

[0010] Furthermore, the rail is provided on a workbench, the workbench supports the work object, and the robot performs work operations on the work object. [Effects of the Invention]

[0011] According to the present invention, the following effects can be obtained.

[0012] The control of movement and work is integrated, enabling seamless automation from fixed-point stop to work.

[0013] Stable motions are reproduced based on the work motion information stored for each fixed point, so work accuracy and efficiency are improved.

[0014] With the configuration on the workbench, the relative position to the work target is always constant, enabling high-precision work.

[0015] Operation using a GUI allows on-site workers to easily register and update fixed points and work, and also provides excellent maintainability and scalability. [Brief Description of the Drawings]

[0016] [Figure 1] is an overall configuration diagram of the robot control system of the present invention, and is a diagram showing a state where the cart carrying the robot is at a first fixed point position. [Figure 2] is a diagram showing a state where the cart carrying the robot is at a second fixed point position. [Figure 3] is a diagram showing a state where the cart carrying the robot is at a third fixed point position. [Mode for Carrying Out the Invention]

[0017] <1. Overall System Configuration> The robot control system according to the present invention is configured to automatically perform work at a specific fixed point position on a production line in a factory or the like, and includes a movable cart, a robot mounted on the cart, and a control device that controls movement and fixed-point stop of the cart.

[0018] As shown in Figure 1, this system 100 is composed of a linear rail 110, a carriage 130 movable along the rail, a robot 140 mounted on the carriage, and a controller 150 (not shown) that controls these components. Furthermore, a workbench 120 that supports a work target 200 is provided, and the robot 140 performs work operations on the work target 200. Figure 1 shows the carriage 130 at a first fixed point position, Figure 2 shows the state where the carriage 130 has moved to a second fixed point position, and Figure 3 shows the state where the carriage 130 has moved to a third fixed point position.

[0019] The rail 110 is made of a high-rigidity member such as an extruded aluminum material, extends linearly, and the carriage 130 is movable in the front-rear direction along a guide structure formed on the rail 110. The rail 110 is installed so as to include at least fixed point positions P1 to Pn.

[0020] As an example of the embodiment, the rail 110 is fixedly installed on the workbench 120. The workbench 120 is a work support structure made of steel, aluminum frame, or wood, on which a plurality of work targets 200 are arranged in process order. The carriage 130 moves along the rail 110 and stops at the fixed point positions, so that the robot 140 is configured to perform work corresponding to each process. Since the relative position between the workbench 120 and the rail 110 is always constant, the positional relationship between the robot 140 and the work target 200 is also maintained with repeat accuracy.

[0021] The carriage 130 consists of a frame structure, and is provided with a mounting portion on its upper surface that can fix the robot 140. A roller, a slider, or a guide block is mounted on the lower surface of the carriage, and the carriage is configured to move linearly by sliding or rolling with respect to the rail 110. In addition, the carriage 130 includes an electric motor, a speed reducer, a drive pulley, and the like, and moves to and stops at a predetermined position according to a command from the controller 150.

[0022] Robot 140 is a collaborative or industrial robotic arm fixed on the trolley 130, configured to perform a corresponding task when the trolley stops at a predetermined fixed point. The tasks of robot 140 are pre-set to correspond to each fixed point and operate in conjunction with the trolley's stopping motion. This system primarily consists of controlling the trolley's movement and managing its stopping position, and associating these with the corresponding work actions at that position.

[0023] The control device 150 consists of a PLC or microcontroller-based control board and has control functions such as drive control of the trolley 130, fixed point detection, operation control of the locking mechanism, and output of a work start signal. As a result, when the trolley reaches the fixed point position, the start of work is triggered based on the stored work response information.

[0024] Cables for power supply and signal communication are connected to the rails 110 and bogies 130, and are protected by cable carriers and movable cable protection tubes. The wiring configuration connects the control device to each component, enabling highly reliable operation.

[0025] As described above, the robot control system of the present invention enables highly repeatable work at multiple fixed points while stably maintaining the positional relationship between the movement and stopping position of the trolley and the position of the workpiece. This greatly contributes to reducing setup time, standardizing work, and promoting automation in the production process.

[0026] <2. Details of trolley movement and stopping control> In the robot control system according to the present invention, the movement control and stopping control of the trolley are core elements for enabling high-precision work execution at fixed positions. This section describes in detail the trolley drive structure, the movement control procedure, the means for detecting the fixed position, and the means for stabilization after stopping.

[0027] As shown in Figure 1, the trolley 130 is configured to move along the rail 110, and multiple fixed positions P1 through Pn are set on the rail 110. The trolley 130 has a drive system consisting of a drive motor 131, a drive pulley 132, a timing belt 133, etc., which are operated by drive signals from the control device 150. The rail 110 has a linear guide structure and is designed to achieve high linearity and low friction in the straight line movement of the trolley 130.

[0028] A stepping motor or an AC servo motor is suitable as the drive motor 131, and a stepping motor is particularly advantageous in applications requiring high positioning accuracy. The control device 150 transmits pulse signals to the drive motor 131 via a motor driver to control the travel distance, speed, and acceleration / deceleration timing. The acceleration time, constant speed time, and deceleration time can each be parameter-set according to the process and load conditions, ensuring smooth and stable movement.

[0029] The movement of the trolley 130 is not simply controlled by ON / OFF, but is configured to start smoothly using acceleration control and automatically decelerate just before reaching the fixed position. This prevents vibrations caused by sudden stops of the motor and overruns of the trolley, and maintains accuracy in its relative position to the workpiece 200.

[0030] For detecting the fixed point position Pn, a configuration consisting of a Hall sensor 136 provided on the trolley 130 and a magnetic marker 111 attached to the rail 110 is preferred. The magnetic marker 111 is installed at predetermined intervals using neodymium magnets or magnetic tape, and each fixed point has a unique polarity or magnetic pattern. When the trolley approaches the fixed point position, the Hall sensor 136 detects the magnetic marker, and the signal is transmitted to the control device 150.

[0031] When the control device 150 receives a detection signal from the Hall sensor 136, it immediately stops the pulse signal to the drive motor 131, thereby stopping the movement of the trolley 130. At this time, in order to prevent overrunning due to inertia, deceleration control is performed in advance from before the fixed point, enabling a smooth stop. Furthermore, immediately after stopping, the locking mechanism (details described later) is activated to mechanically fix the position, thereby suppressing positional displacement.

[0032] Regarding the stopping accuracy of the trolley, the design assumes a detection error (e.g., ±1.0 mm) from the Hall sensor and magnetic marker. To compensate for this, it is preferable to have a locking mechanism equipped with a fitting guide surface (e.g., a conical guide or tapered sleeve) that automatically centers the trolley after stopping. This achieves a repeatability accuracy of ±0.5 mm or less for the final stopping position.

[0033] Furthermore, in terms of movement control, multiple operation profiles are pre-stored within the control device 150 to accommodate differences in movement distance and work content at each fixed point. These profiles include movement speed, acceleration, and deceleration timing corresponding to each fixed point, allowing for flexible response to changes in the work process at the site.

[0034] Regarding error handling, it is desirable that the control device 150 immediately stops the movement of the trolley and outputs an alert signal if the trolley fails to reach a fixed position (for example, if the magnetic marker is not detected). In addition, if an abnormal condition is detected, the control device 150 should save the relevant log to its internal memory and output the error code and status history via an external interface, thereby improving maintainability and safety.

[0035] Furthermore, when the travel distance is long, a configuration can be adopted in which a belt tensioner 134 is installed at an intermediate support point to suppress positional errors due to deflection or stretching of the timing belt 133. This stabilizes the transmission of driving force to the trolley 130 and maintains high-precision position control even during long-distance travel.

[0036] In this invention, the control design goes beyond mere movement control, and is integrated with sensor control, drive control, error correction, and abnormality response to ensure that "robot work can be started without positional displacement after stopping at a fixed point." As a result, a stable working environment is always maintained at each work station, leading to improved productivity and standardization of processes.

[0037] <3. Configuration and Operation of the Locking Mechanism> In this invention, simply stopping the drive is insufficient to stably fix the trolley in a fixed position; a locking mechanism with physical restraint is essential. In particular, when a robot performs high-precision tasks such as fine machining, assembly, or measurement, even minute vibrations or misalignments of the trolley can cause work errors, making a configuration that mechanically fixes the trolley extremely important.

[0038] As shown in Figure 4, the locking mechanism 200 according to the present invention consists of a locking portion 210 provided on the trolley 130 side and an engaging portion 220 provided on the rail 110 side. The locking portion 210 includes an electromagnetic solenoid 211, a movable pin 212, and a pin guide 213. The electromagnetic solenoid 211 is energized by a control signal from the control device 150, causing the internal movable core to move back and forth. The movable pin 212, connected to the movable core, is inserted into the engaging portion 220 with a predetermined operating stroke.

[0039] The engaging portion 220 is a through hole or recess provided in the rail 110, into which the tip of the pin 212 is inserted, thereby fixing the bogie 130 relative to the rail 110. A replaceable sleeve 221 is inserted into the engaging portion 220, and by replacing only this part when it wears out, the maintainability of the entire locking mechanism is improved.

[0040] The tip of the movable pin 212 in the locking portion 210 is machined into a conical or spherical shape, and an inclined guide surface is also provided on the inner edge of the engaging portion 220. As a result, even if the position is slightly misaligned, the pin is automatically guided and engages accurately. This makes it possible to correct the stopping accuracy to a fixed position to ±0.5 mm or less.

[0041] When the trolley 130 reaches the fixed position Pn, the Hall sensor 136 first detects the magnetic marker 111, and the signal is transmitted to the control device 150. Upon receiving this signal, the control device 150 stops the pulse signal to the drive motor 131 and simultaneously outputs an energization command to the locking mechanism 200. As a result, the electromagnetic solenoid 211 is activated, the movable pin 212 moves forward and is inserted into the engagement part 220, and the trolley 130 is physically fixed at the predetermined fixed position.

[0042] In this way, the seamless coordination between the stopping and locking operations enables the trolley 130 to achieve highly reproducible fixed-point stopping, thereby stably supporting the subsequent work operations of the robot 140.

[0043] In the locking mechanism 200, the pin is made of hardened high-carbon steel, and a steel bushing designed for wear resistance is inserted into the engaging sleeve 221. In addition, the movable pin 212 is lubricated with grease or dry lubrication to allow it to move smoothly within the pin guide 213.

[0044] The locking mechanism according to the present invention also includes a manual release mechanism for emergency situations. Specifically, a manual release lever 214 is provided on the side of the trolley 130, and in the event of a power outage or solenoid failure, an operator can operate the lever to retract the pin 212 with spring force, thereby releasing the engagement. The manual release lever is designed with visibility and operability in mind and is structured to comply with safety standards.

[0045] Furthermore, the locking mechanism of the present invention is not limited to a configuration in which a locking part is provided on the bogie side and an engaging part is provided on the rail side. As a modification, a configuration in which a movable locking claw is provided on the rail side and a recess or slot is provided on the bogie side for engagement, or an engaging structure using an electric cam or pneumatic cylinder can also be adopted. These configurations are also included in the technical scope of claim 2.

[0046] Furthermore, by providing a lock sensor (e.g., a reed switch or photosensor) in the locking mechanism as a means of monitoring the locked state, the control device 150 can monitor the engagement state of the pins. This further enhances safety and reliability by allowing the robot 140 to output a work start signal only after confirming that the lock has been successfully engaged.

[0047] As described above, the locking mechanism according to the present invention is effective in multiple respects, including ensuring stopping accuracy, maintaining position during operation, suppressing vibration, ensuring safety, and improving maintainability, and is an indispensable element for realizing fixed-point work in robot control systems.

[0048] <4. Control device configuration and stored information> In the robot control system according to the present invention, the control device 150 is a core element that centrally controls the movement control of the trolley 130, the detection processing of fixed point positions, the operation of the locking mechanism after stopping, and the output processing of work start signals at each fixed point. The control device 150 is composed of an industrial PLC (programmable logic controller), a microcontroller-based control board, or an embedded miniature computer, and has real-time processing capability and flexible expandability.

[0049] The control device 150 includes the following functional blocks:

[0050] Movement control unit: Performs movement control by outputting pulse signals to the drive motor 131 of the trolley 130. Position determination unit: Receives detection signals from the magnetic marker 111 by the Hall sensor 136 and determines when the fixed point has been reached. Lock control unit: Outputs an activation signal for the lock mechanism 200 upon arrival, securing the trolley. Trigger output unit: After locking is complete, it outputs a trigger signal to the robot 140 to start work based on the stored information. Memory Unit: Stores the correspondence between each fixed point position and work operation, as well as various parameters.

[0051] The memory unit 151 is composed of EEPROM, flash memory, or non-volatile RAM, and data can be updated from an external source. The information stored is recorded as pairs of the following data for each fixed point:

[0052] Fixed point identifiers (e.g., P1, P2, ...) The distance or pattern of movement of the trolley (e.g., distance X1, speed V1, etc.) The corresponding work action trigger output signal (e.g., digital I / O port number) Delay time before trigger output (e.g., 0.5 seconds to 5 seconds)

[0053] These data are stored in a table format within the control device 150, and actions corresponding to the fixed point location are executed sequentially. Specifically, after receiving the signal indicating arrival at the fixed point, the control device 150 confirms that the lock mechanism 200 has completed operation, retrieves the corresponding trigger information, and sends a command to start work to an externally connected robot control device via a digital signal or communication protocol.

[0054] The trigger signal is typically output via a 24V digital I / O signal, but it is also compatible with industrial communication standards such as RS-232C, RS-485, EtherCAT, PROFINET, and Modbus-TCP. The output timing is designed to occur after a predetermined delay period following lock completion, allowing operation to begin only after mechanical vibrations and instability have subsided.

[0055] Furthermore, the memory unit 151 is also equipped with a function for updating fixed-point information and trigger information via an external interface. For example, it is possible to import information in CSV file format using a USB memory stick, or to remotely update it from a higher-level system connected via Ethernet. This configuration allows for flexible response to changes in the work process or the arrangement of work stations on site.

[0056] The control device 150 also includes a status monitoring function, which records the processing history of each step (reaching a fixed point, lock completion, trigger output) in chronological order. This makes it easier to identify the cause of any malfunctions or troubles, improving maintainability. The records can be saved to an SD card, internal memory, or external cloud storage.

[0057] Furthermore, from a safety standpoint, the following protective functions are also implemented in the control unit 150:

[0058] If a lock completion signal is not received, the trigger output is held or disabled. If the motor does not reach the designated position, it will be forcibly stopped and an alert signal will be generated. Based on the monitoring results of the lock status, abnormal statuses are recorded and output to the work log. If the next step is not performed within the specified time, the system will automatically transition to failsafe mode.

[0059] As described above, the control device of the present invention has the function of consistently managing everything from the movement of the trolley to the output of the start of work, and is configured to closely link stored information and control processing for high-precision operation at a fixed point. With this configuration, high performance can be achieved in terms of work reproducibility, process automation, safety, and maintainability.

[0060] (supplement) The functions and configurations described in each embodiment of the present invention are not limited to being implemented individually, and the described elements and functions can be combined as appropriate within the scope of technical compatibility. Therefore, the scope of the present invention accommodates a wide variety of modifications, including these combinations. [Industrial applicability]

[0061] The robot control system according to the present invention can be used in a wide range of industrial fields, including manufacturing, assembly and processing, logistics, and research and development sites. In particular, it is highly useful in that it can automate and reduce labor in work processes while keeping capital investment low by moving a single robot mounted on a cart to multiple work stations. [Explanation of symbols]

[0062] 100 Robot Control Systems 110 rails 111 Magnetic Marker 120 Workbenches 130 bogies 131 Drive motor 132 Drive pulley 133 Timing belt 134 Belt Tensioner 135 Locking pins 136 Hall Sensor 140 robots 150 Control device 151 Storage section 200 Locking Mechanism 210 Locking part 211 Electromagnetic solenoid 212 Movable pins 213 Pin Guide 214 Manual release lever 220 Engaging part 221 Engagement Sleeve Fixed position from P1 to Pn 300 Work Objects

Claims

1. A trolley configured to move along rails, and a robot mounted on the trolley, The system includes a control device that controls the movement of the trolley and the working movements of the robot, The control device is The trolley is moved toward at least one of a plurality of predetermined fixed points, The trolley is stopped at the fixed point position, Movement information and work operation information are stored in association with each other to allow the robot to perform a work operation at the stopping position. Based on the stored information, the movement of the trolley and the work actions of the robot are executed sequentially. A robot control system characterized by the following features.

2. In the robot control system according to claim 1, The rail and the trolley are each equipped with a locking mechanism for physically fixing the trolley at two or more predetermined fixed positions. The locking mechanism is characterized by the locking of the trolley and the engagement of the rail, thereby fixing the trolley in the fixed position.

3. In the robot control system according to claim 1, The aforementioned rail is installed on the workbench, The aforementioned workbench supports the object to be worked on, The robot control system is characterized by the robot performing work operations on the object to be worked on.

Images