Mobile grinding robot consumable service life monitoring and automatic replacement system and method

Abstract

The invention discloses a consumable service life monitoring and automatic replacement system and method for a mobile grinding robot, and relates to intelligent manufacturing and industrial robots. According to the method, the preprocessed working current is compared with a failure threshold value through a consumable service life monitoring algorithm, and whether the current consumable fails or not is judged. According to the service life judgment based on the working current, waste of consumables and fluctuation of machining quality are avoided. And the force control grinding head is controlled to make contact with the stripping mechanism based on Z-axis displacement and grinding disc pressure through a consumable replacement control algorithm, and the current consumable is torn down through resistance of the stripping mechanism. Complex actions are completed through the movement capacity of the movable grinding robot, and the fault rate is reduced. The movable grinding robot moves to the position above the rigid datum plane, and the Z-axis is controlled to probe downwards; and judging whether the current consumables fall off successfully based on the Z-axis displacement. Consumable replacement verification is carried out through negative pressure adsorption detection, visual detection or a rigid reference surface. Through double verification steps, the reliability problem in unmanned operation is solved.

Description

Technical Field

[0001] This invention relates to the field of intelligent manufacturing and industrial robots, and more specifically, to a system and method for monitoring and automatically replacing consumables for a mobile grinding robot. Background Technology

[0002] In surface treatment of large workpieces such as roughening high-speed rail flooring and polishing wind turbine blades, robots need to operate continuously for extended periods. Grinding consumables (sandpaper / scouring pads) are high-frequency wear parts, and their condition directly affects the quality of the work. Currently, the following pain points exist: 1. Lifespan assessment relies on guesswork: Current technologies mostly use the "fixed time method" or "fixed area method" to replace consumables. Replacing consumables before they are worn out is wasteful; continuing to grind consumables that are already worn out (e.g., due to premature failure at hard points) can lead to "slippage" or "burning of the workpiece".

[0003] 2. Low efficiency of manual replacement: AGVs move in large workshops, and if manual replacement is required, the machine must be stopped and workers must move on, resulting in extremely low OEE (Overall Equipment Effectiveness). Furthermore, after the robot replaces the sandpaper, it's unclear whether it has adhered properly or whether the old sandpaper has been completely removed, frequently leading to "paper stacking" or "paper falling" incidents. Summary of the Invention

[0004] In view of this, the present invention provides a system and method for monitoring and automatically replacing consumable life of mobile grinding robots, which solves the problems of inaccurate consumable life monitoring and replacement methods and low efficiency of manual consumable replacement.

[0005] To achieve the above objectives, the following solution is proposed: A mobile polishing robot consumable life monitoring and automatic replacement system, the system includes: a mobile polishing robot and a consumable replenishment device; The mobile grinding robot includes a controller, a force-controlled grinding head, a tray interface, a spindle current sensor, a displacement sensor, and a pressure sensor; The force-controlled grinding head is connected to consumables via a tray interface; The spindle current sensor collects the real-time operating current of the spindle motor; the displacement sensor and the pressure sensor are used to collect the Z-axis displacement and grinding disc pressure of the force-controlled grinding head, respectively. The controller stores a consumable life monitoring algorithm and a consumable replacement control algorithm; the consumable life monitoring algorithm performs real-time analysis of consumable life based on real-time operating current; the consumable replacement control algorithm controls the mobile grinding robot to automatically replace consumables in the consumable supply device based on Z-axis displacement and grinding disc pressure. The consumable replenishment device includes a stripping mechanism and a consumable feeding mechanism; The consumable feeding mechanism is used to hold new consumables to be replaced, and the peeling mechanism allows the mobile grinding robot to peel off old consumables through a protruding part.

[0006] Preferably, the tray interface is located on the bottom surface of the force-controlled grinding head.

[0007] Preferably, the tray interface is a Velcro strap.

[0008] Preferably, the peeling mechanism is a metal shovel or a barbed rack.

[0009] Preferably, the consumable feeding mechanism is provided with a spring lifting device at the bottom to keep the new consumable to be replaced at a fixed height.

[0010] Preferably, the consumable supply device further includes: a rigid reference surface; The rigid reference surface is used by the mobile polishing robot to determine whether the old consumables have been successfully removed.

[0011] A method for monitoring and automatically replacing consumable lifespan in a mobile grinding robot, applied to the aforementioned system for monitoring and automatically replacing consumable lifespan in a mobile grinding robot, comprising: During the grinding process, the spindle current sensor collects the real-time operating current of the spindle motor and uploads it to the controller. The real-time operating current is preprocessed by the consumable life monitoring algorithm, and the preprocessed operating current is compared with the failure threshold to determine whether the current consumable has failed. If the current consumable fails, the mobile polishing robot will pause its operation, record the current breakpoint coordinates, and move to the consumable replenishment device. The consumable replacement control algorithm controls the force-controlled grinding head to contact the peeling mechanism based on Z-axis displacement and grinding disc pressure, and the current consumable is torn off by the resistance of the peeling mechanism. The mobile grinding robot moves to the consumables feeding mechanism and controls the Z-axis of the force-controlled grinding head to press down, so that the tray interface connects with the consumable to be replaced. The mobile grinding robot returns to its previous breakpoint coordinates and continues the grinding operation.

[0012] Preferably, after the current consumable is torn off by the resistance of the peeling mechanism, the process further includes: The mobile grinding robot moves above the rigid reference surface and controls the Z-axis to move downwards until the grinding disc pressure reaches the preset value. Obtain the Z-axis displacement and determine whether the consumable has been successfully detached based on the Z-axis displacement.

[0013] Preferably, after the tray interface is connected to the consumable to be replaced, the method further includes: The mobile polishing robot lifts the force-controlled polishing head and verifies consumable replacement through negative pressure adsorption detection, visual inspection, or a rigid reference surface.

[0014] Preferably, the process of consumable life monitoring algorithm performing consumable life analysis includes: If the operating current is less than the failure threshold for a continuous preset time period, the current consumable is confirmed to be faulty.

[0015] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: (1) The mobile grinding robot consumable life monitoring and automatic replacement method provided by the present invention preprocesses the real-time working current through a consumable life monitoring algorithm, and compares the preprocessed working current with the failure threshold to determine whether the current consumable has failed. The life judgment based on the working current of the present invention avoids waste of consumables and fluctuations in processing quality, and improves the consumable utilization rate by more than 20% compared with the traditional timing method.

[0016] (2) This invention uses a consumable replacement control algorithm based on Z-axis displacement and grinding disc pressure to control the contact between the grinding head and the peeling mechanism. The current consumable is torn off by the resistance of the peeling mechanism. The peeling mechanism of this invention uses a "passive scraper" to complete complex actions by utilizing the motion capability of the mobile grinding robot itself, eliminating the need for expensive dedicated peeling motors and robotic arms, and reducing the failure rate.

[0017] (3) After the present invention removes the current consumable by the resistance of the peeling mechanism, it moves the grinding robot to the top of the rigid reference surface and controls the Z-axis to move down until the grinding disk pressure reaches the preset value. The Z-axis displacement is acquired, and the success of consumable detachment is determined based on this displacement. After the tray interface connects to the consumable to be replaced, the mobile grinding robot is controlled to raise the force-controlled grinding head, and consumable replacement is verified through negative pressure adsorption detection, visual inspection, or a rigid reference surface. This invention introduces a dual verification process of "successful detachment verification" and "successful installation verification," solving the reliability problem in unmanned operations. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the consumable life monitoring and automatic replacement system for a mobile grinding robot provided in an embodiment of the present invention; Figure 2 A flowchart illustrating the method for monitoring and automatically replacing consumables in a mobile grinding robot, as provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] First, combined Figure 1 This invention introduces a mobile grinding robot consumable life monitoring and automatic replacement system provided by an embodiment of the present invention, such as... Figure 1 As shown, the system mainly consists of two parts: a mobile grinding robot and a consumable supply device.

[0022] The mobile grinding robot includes a controller, a force-controlled grinding head, a tray interface, a spindle current sensor, a displacement sensor, and a pressure sensor.

[0023] The force-controlled grinding head features radial / axial flexible floating, and the tray interface is located on the bottom surface of the grinding disc. The force-controlled grinding head connects to consumables via the tray interface. For example, if the tray interface is Velcro, the bottom surface of the grinding disc has a Velcro hookface for attaching lint-backed consumables.

[0024] The spindle current sensor, displacement sensor, and pressure sensor are integrated into the force-controlled grinding head. The spindle current sensor (sampling frequency > 50Hz) collects the real-time operating current of the spindle motor; the displacement sensor and pressure sensor are used to collect the Z-axis displacement and grinding disc pressure of the force-controlled grinding head, respectively.

[0025] The controller stores consumable life monitoring algorithms and consumable replacement control algorithms. The consumable life monitoring algorithm performs real-time analysis of consumable life based on real-time operating current. The consumable replacement control algorithm controls the moving grinding robot to automatically replace consumables in the consumable supply device based on Z-axis displacement and grinding disc pressure.

[0026] The consumables replenishment device can be a fixed floor support, mainly consisting of a stripping mechanism and a consumables feeding mechanism.

[0027] The consumables feeding mechanism holds the new consumables to be replaced, which are stacked inside. A spring-loaded lifting device is installed at the bottom to keep the topmost new consumable at a fixed height.

[0028] The stripping mechanism is passive and does not have a motor. It uses a protruding part for the moving grinding robot to strip the old consumables. The stripping mechanism is a protruding metal scraper or barbed rack, which relies on the grinding disc of the moving grinding robot to "rub" upwards to strip the old consumables. The material hardness of the protrusion of the stripping mechanism is lower than that of the grinding disc of the force-controlled grinding head, or a limit stop is set on the protrusion to prevent the robot from accidentally damaging the grinding disc and the tray interface.

[0029] In addition, such as Figure 1 As shown, the consumable supply device may also include a rigid reference surface.

[0030] A rigid reference surface is provided to allow the mobile grinding robot to determine whether the old consumables have been successfully peeled off or installed based on the Z-axis displacement.

[0031] Next, in conjunction with the embodiments of the present invention Figure 2 This invention provides a method for monitoring and automatically replacing consumables in a mobile grinding robot applied to the aforementioned system, as described in an embodiment of the invention. Figure 2 As shown, the method includes: Step S1: During the grinding process, the spindle current sensor collects the real-time operating current of the spindle motor and uploads it to the controller.

[0032] Specifically, in constant contact force grinding mode, the load torque of the spindle motor is proportional to the coefficient of friction between the grinding disc and the workpiece. When the consumable is sharp, the coefficient of friction is high, and the operating current required to maintain the rotational speed is high. As the consumable wears (the abrasive grains become blunt), the coefficient of friction decreases, the load decreases, and the operating current shows a downward trend. During the grinding process, the controller records the operating current of the spindle motor in real time.

[0033] Step S2: Preprocess the real-time operating current using a consumable life monitoring algorithm.

[0034] Specifically, a moving average filtering algorithm is used to remove instantaneous current spikes caused by weld vibration.

[0035] Step S3: Determine if the current consumable is invalid.

[0036] Specifically, a failure threshold is set. The pre-processed operating current is compared with the failure threshold. If the operating current is less than the failure threshold for a continuous period of T seconds, the current consumable is confirmed to have failed.

[0037] This invention incorporates a "T-second delay confirmation" mechanism. Consumable replacement is only triggered if the operating current remains below the failure threshold for T consecutive seconds, preventing misjudgments caused by localized smoothness on the floor. This method is more accurate than traditional timing methods and can identify situations where sandpaper is instantly rendered unusable due to contact with a hard object.

[0038] Step S4: The mobile grinding robot pauses its operation, records the current breakpoint coordinates, and moves to the consumables replenishment device.

[0039] Specifically, if the current consumable material fails, it needs to be replaced. At this time, the mobile polishing robot pauses its operation, records the current breakpoint coordinates, and moves to the consumable material replenishment device.

[0040] Step S5: Based on the Z-axis displacement and grinding disc pressure, the consumable replacement control algorithm controls the force-controlled grinding head to contact the peeling mechanism, and the current consumable is torn off by the resistance of the peeling mechanism.

[0041] Specifically, multi-pose stripping is performed: Action A (Cutting): Move the grinding robot to adjust its posture so that the edge of the grinding disc cuts into the underside of the peeling mechanism protrusion at an angle, scraping up the edge of the old consumables. For example, the edge of the grinding disc is tilted at 15° to cut into the underside of the scraper, scraping up the edge of the old sandpaper.

[0042] Action B (Tearing): The moving sanding robot maintains downward pressure along the Z-axis while simultaneously moving horizontally (X / Y direction). Utilizing the resistance of the peeling mechanism's protrusions, the current consumable is completely torn off the tray interface. For example, using the resistance of the scraper to completely tear old sandpaper off the Velcro base.

[0043] Action C (Discard): The old consumables fall into the waste bin below.

[0044] Step S6: The mobile grinding robot moves to the consumable feeding mechanism and controls the Z-axis of the force-controlled grinding head to press down, so that the tray interface is connected to the consumable to be replaced.

[0045] Specifically, move the sanding robot to the consumable feeding mechanism and align it with the center. Press down on the Z-axis to bring the tray interface into contact with the new consumable. You can compact it by rotating it; while maintaining pressure, rotate the spindle at low speed and swing it left and right to ensure a secure installation. For example, press down on the Z-axis to bring the Velcro side of the grinding disc into contact with the backing of the new sandpaper. Maintain 50N of pressure, rotate the spindle at 60RPM, and swing it left and right to ensure a firm bond.

[0046] Step S7: Move the grinding robot back to the previous breakpoint coordinates and continue the grinding operation.

[0047] Specifically, the mobile polishing robot returns to the previous breakpoint coordinates, resets the consumable life monitoring algorithm, and continues the polishing operation.

[0048] Furthermore, to avoid accidents such as "paper stacking" or "paper falling," this embodiment of the invention, based on the method of the aforementioned embodiments, in step S5, after the current consumable is torn off by the resistance of the peeling mechanism, a successful peeling verification is performed: The mobile grinding robot moves above the rigid reference surface and controls the Z-axis to move downwards until the grinding disc pressure reaches the preset value.

[0049] Obtain the Z-axis displacement and determine whether the consumable has been successfully detached based on the Z-axis displacement.

[0050] Specifically, if the Z-axis displacement is the same as the standard reference height, it means that the old consumables have been lost, and only the bare disk remains.

[0051] If the Z-axis displacement is less than the standard reference height, it indicates that the height is too high and the old consumables have not fallen. This will trigger an alarm or return to step S5.

[0052] Similarly, in step S6, after connecting the tray interface to the consumable to be replaced, the installation success can be verified: The mobile grinding robot lifts the force-controlled grinding head and verifies consumable replacement through negative pressure adsorption detection, visual inspection, or a rigid reference surface.

[0053] The process of verifying consumable replacement on the rigid reference surface is the same as the aforementioned successful stripping verification process. At this time, if the Z-axis displacement is less than the standard reference height, it means that the height is too high and the new consumable is successfully installed; if the Z-axis displacement is the same as the standard reference height, an alarm is triggered or the process returns to step S6.

[0054] This invention utilizes the current feedback of the force-controlled spindle to accurately predict its lifespan, and leverages the robot's own degrees of freedom of motion in conjunction with passive tooling to achieve low-cost, highly reliable automatic replacement.

[0055] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0056] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A consumable life monitoring and automatic replacement system for a mobile grinding robot, characterized in that, The system includes: Mobile polishing robot and consumable supply device; The mobile grinding robot includes a controller, a force-controlled grinding head, a tray interface, a spindle current sensor, a displacement sensor, and a pressure sensor; The force-controlled grinding head is connected to consumables via a tray interface; The spindle current sensor collects the real-time operating current of the spindle motor; the displacement sensor and the pressure sensor are used to collect the Z-axis displacement and grinding disc pressure of the force-controlled grinding head, respectively. The controller stores a consumable life monitoring algorithm and a consumable replacement control algorithm; the consumable life monitoring algorithm performs real-time analysis of consumable life based on real-time operating current; the consumable replacement control algorithm controls the mobile grinding robot to automatically replace consumables in the consumable supply device based on Z-axis displacement and grinding disc pressure. The consumable replenishment device includes a stripping mechanism and a consumable feeding mechanism; The consumable feeding mechanism is used to hold new consumables to be replaced, and the peeling mechanism allows the mobile grinding robot to peel off old consumables through a protruding part.

2. The mobile grinding robot consumable life monitoring and automatic replacement system according to claim 1, characterized in that, The tray interface is located on the bottom surface of the force-controlled grinding head.

3. The mobile grinding robot consumable life monitoring and automatic replacement system according to claim 1, characterized in that, The tray interface is Velcro.

4. The mobile grinding robot consumable life monitoring and automatic replacement system according to claim 1, characterized in that, The peeling mechanism is a metal shovel or a barbed rack.

5. The mobile grinding robot consumable life monitoring and automatic replacement system according to claim 1, characterized in that, The consumables feeding mechanism is equipped with a spring lifting device at the bottom to keep the new consumables to be replaced at a fixed height.

6. The mobile grinding robot consumable life monitoring and automatic replacement system according to any one of claims 1-5, characterized in that, The consumable supply device further includes: a rigid reference surface; The rigid reference surface is used to determine whether invalid consumables have been successfully peeled off or installed based on Z-axis displacement.

7. A method for monitoring and automatically replacing consumable life of a mobile grinding robot, characterized in that, The system for monitoring and automatically replacing consumable life of a mobile grinding robot as described in any one of claims 1-6 includes: During the grinding process, the spindle current sensor collects the real-time operating current of the spindle motor and uploads it to the controller. The real-time operating current is preprocessed by the consumable life monitoring algorithm, and the preprocessed operating current is compared with the failure threshold to determine whether the current consumable has failed. If the current consumable fails, the mobile polishing robot will pause its operation, record the current breakpoint coordinates, and move to the consumable replenishment device. The consumable replacement control algorithm controls the force-controlled grinding head to contact the peeling mechanism based on Z-axis displacement and grinding disc pressure, and the current consumable is torn off by the resistance of the peeling mechanism. The mobile grinding robot moves to the consumables feeding mechanism and controls the Z-axis of the force-controlled grinding head to press down, so that the tray interface connects with the consumable to be replaced. The mobile grinding robot returns to its previous breakpoint coordinates and continues the grinding operation.

8. The method for monitoring and automatically replacing consumable life of a mobile grinding robot according to claim 7, characterized in that, After the current consumable is torn off by the resistance of the peeling mechanism, the process also includes: The mobile grinding robot moves above the rigid reference surface and controls the Z-axis to move downwards until the grinding disc pressure reaches the preset value. Obtain the Z-axis displacement and determine whether the consumable has been successfully detached based on the Z-axis displacement.

9. The method for monitoring and automatically replacing consumable life of a mobile grinding robot according to claim 7, characterized in that, After the tray interface is connected to the consumable to be replaced, the following is also included: The mobile polishing robot lifts the force-controlled polishing head and verifies consumable replacement through negative pressure adsorption detection, visual inspection, or a rigid reference surface.

10. The method for monitoring and automatically replacing consumable life of a mobile grinding robot according to claim 7, characterized in that, The process of consumable life monitoring algorithm performing consumable life analysis includes: If the operating current is less than the failure threshold for a continuous preset time period, the current consumable is confirmed to be faulty.

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