Method for determining and avoiding steel bar interference

Abstract

This invention provides a method for determining and avoiding rebar interference, which is implemented by a robot equipped with a drill bit when drilling a hole in a wall. The method for determining and avoiding rebar interference is characterized by the following steps: collecting the joint load current of each joint of the robot and the tool load current of the drill bit; determining whether there is rebar interference in the wall when drilling based on the joint load current and the tool load current; and tilting the drill bit to avoid the rebar if rebar interference is determined to exist.

Description

Technical Field

[0001] This invention relates to a method for determining and avoiding steel bar interference when a robot equipped with a drill bit is drilling a hole in a wall. Background Technology

[0002] When a robot drills a hole in a concrete wall, the drill bit often collides with the steel bars inside the wall, causing it to be in an overloaded state. If effective measures are not taken in time, the motor will burn out and the drill bit and gears will be damaged.

[0003] Patent document 1 discloses an overload protector for a concrete drilling machine. When the concrete drilling machine is drilling holes in concrete, if an overload occurs, the circuit immediately cuts off the motor power supply to stop drilling, thereby achieving the purpose of overload protection.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: CN2441250Y Summary of the Invention

[0007] The problem the invention aims to solve

[0008] While the aforementioned patent document 1 achieves the purpose of overload protection, it cannot automatically avoid the reinforcing bars, requiring the drilling of new holes, which is time-consuming, labor-intensive, and inefficient. Furthermore, even after drilling new holes, there is still a possibility of contact with the reinforcing bars again, failing to fundamentally solve the problem.

[0009] In addition, if the diameter of the rebar is Φ6~Φ15mm, the size is relatively small, and the embedment is relatively deep (more than 60mm), the existing rebar scanners will have difficulty detecting it.

[0010] This invention was made to solve the above-mentioned problems, and its purpose is to provide a method for effectively determining whether there is steel bar interference when drilling holes in a wall and immediately avoiding it.

[0011] Technical means to solve the problem

[0012] The first aspect of the present invention is a method for determining and avoiding steel bar interference, which is implemented by a robot equipped with a drill bit when drilling a hole in a wall. The method for determining and avoiding steel bar interference is characterized by including the following steps: collecting the joint load current of each joint of the robot and the tool load current of the drill bit; determining whether there is steel bar interference in the wall when drilling based on the joint load current and the tool load current; and tilting the drill bit to avoid the steel bar if steel bar interference is determined to exist.

[0013] In the above-mentioned method for determining and avoiding steel bar interference, based on the joint load current and the tool load current, the load value increase rate or average current ratio of each joint and the drill bit during drilling is calculated, thereby determining whether there is steel bar interference in the wall during drilling.

[0014] In the above-mentioned method for determining and avoiding steel bar interference, steel bar interference is determined to exist when any one of the load value increase rate during drilling of each joint and the drill bit is 120% or more, or when any one of the average current ratio during drilling of each joint and the drill bit exceeds 100%.

[0015] In the above-mentioned method for determining and avoiding steel bar interference, if steel bar interference is determined to exist, the drill bit is first tilted horizontally and moved forward to determine whether steel bar interference still exists. If steel bar interference still exists, the drill bit is then tilted at a specific angle clockwise or counterclockwise and moved forward repeatedly until steel bar interference is determined to be non-existent.

[0016] In the above method for determining and avoiding interference with reinforcing bars, the angle at which the drill bit is tilted along the horizontal direction is greater than angle θ, where angle θ is the arctangent function value of the value obtained by dividing the radius of the reinforcing bar by the length of the drill bit.

[0017] In the above-mentioned method for determining and avoiding interference with reinforcing bars, during the process of tilting the drill bit, the tilting speed is increased sequentially from the lowest speed until the specified conditions are met. The last tilting speed before the specified conditions are met is selected as the optimal tilting speed. The lowest speed is 1% of the maximum speed at which the drill bit can tilt.

[0018] In the above-mentioned method for determining and avoiding interference with reinforcing bars, the specified condition is that any one of the load value increase rate when the joints and the drill bit are tilted is more than 120%, or any one of the average current ratios when the joints and the drill bit are tilted exceeds 100%.

[0019] In the above-mentioned method for determining and avoiding interference with reinforcing bars, the load value increase rate is obtained by dividing the current load value by the previous load value before a specified time. The load value of each joint is obtained by dividing the product of the joint load current, the voltage of each joint, and the energizing time by the rotation angle of each joint. The load value of the drill bit is obtained by dividing the product of the tool load current, the working voltage of the drill bit, and the energizing time by the forward advance of the drill bit.

[0020] In the above-mentioned method for determining and avoiding interference with reinforcing bars, the average current ratio is the average of the joint load current of each joint and the tool load current of the drill bit relative to its rated current within each specified time period.

[0021] The effects of the invention

[0022] According to the present invention, a method is provided for effectively determining and immediately avoiding the presence of reinforcing bars when drilling holes in walls. This method protects the robot from overload due to reinforcing bar interference and significantly improves the efficiency of drilling operations. Furthermore, by selecting an appropriate tilt angle and optimal tilt speed during the process of avoiding reinforcing bars, the time spent avoiding them can be shortened, further improving operational efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a robot according to an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram illustrating data acquisition in an embodiment of the present invention.

[0025] Figure 3 This is a diagram showing the current state of each joint and the drill bit collected in the embodiments of the present invention.

[0026] Figure 4 This is a schematic diagram illustrating the interference determination rules between the drill bit and the reinforcing bar in an embodiment of the present invention.

[0027] Figure 5 This is a diagram showing the current state of each joint and the drill bit under the condition of a load surge in an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram illustrating the automatic avoidance strategy after contact with reinforcing bars according to an embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram illustrating the robot of an embodiment of the present invention tilting in a wall.

[0030] Figure 8 yes Figure 7 AA-direction cross-section diagram. Detailed Implementation

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0032] Implementation

[0033] Figure 1This is a schematic diagram of a robot 100 according to an embodiment of the present invention. The robot 100 is, for example, a six-axis articulated robot, having joints 1, 2, 3, 4, 5, and 6. Although Figure 1 The example shown is a six-axis robot, but it is not limited to this and can also be other multi-axis robots.

[0034] like Figure 1 As shown, a drill bit 110, serving as a tool, is mounted at the end of the robot 100. On the opposite side of the drill bit 110, a current sensor 120 is mounted to detect the load current of the drill bit 110, i.e., the tool load current. Figure 1 The image shows the contact between drill bit 110 and the reinforcing steel inside the concrete wall.

[0035] The following is for reference Figures 2-8 The process of determining and avoiding steel bar interference in the implementation method is explained.

[0036] Figure 2 This is a schematic diagram illustrating data acquisition in an embodiment of the present invention. For example... Figure 2 As shown, the joint load current and rotation angle of each joint 1 to 6 of the robot 100, as well as the tool load current and forward movement of the drill bit 110, are collected. In addition, the voltage and energizing time of each joint 1 to 6, and the operating voltage and energizing time of the drill bit 110 are also collected. The tool load current of the drill bit 110 is obtained through a current sensor 120.

[0037] Figure 3 This diagram illustrates the current state of each joint 1-6 and the drill bit 110 as collected in this embodiment of the invention. The diagram shows the percentage of the joint load current of each joint 1-6 and the tool load current of the drill bit 110 relative to their respective rated currents. Under normal conditions, for example, when the drill bit 110 does not interfere with the reinforcing bar, the joint load current and the tool load current will not exceed their rated currents, i.e., will not exceed... Figure 3 100% of the total.

[0038] Here, the data acquisition cycle is, for example, 10 times per second.

[0039] Next, refer to Figure 4 and Figure 5 The method for determining reinforcement interference in the implementation method is explained.

[0040] Figure 4 This is a schematic diagram illustrating the interference determination rules between the drill bit 110 and the reinforcing bar in an embodiment of the present invention.

[0041] In this embodiment, two judgment rules are used to determine whether the drill bit 110 interferes with the reinforcing bar. Judgment rule 1 is based on the load value increase rate, and judgment rule 2 is based on the average current ratio.

[0042] First, let's explain judgment rule 1.

[0043] In judgment rule 1, the load values ​​of each joint 1 to 6 and the load value of the drill bit 110 are calculated using the previously collected joint load current and rotation angle, voltage and energizing time of each joint 1 to 6, tool load current and feed amount of drill bit 110, and working voltage and energizing time of drill bit 110. The load values ​​of each joint 1 to 6 are calculated using the following formula (1), and the load value of drill bit 110 is calculated using the following formula (2).

[0044]

[0045]

[0046] After calculating the load values ​​of joints 1-6 and drill bit 110, the rate of increase of the current load value compared to the previous load value before a specified time is used to determine whether reinforcement interference has occurred. Specifically, if any one of the rate of increase of the load values ​​of joints 1-6 and drill bit 110 is greater than or equal to 120%, it is determined that drill bit 110 has interfered with the reinforcement in the concrete wall. If each of the rate of increase of the load values ​​of joints 1-6 and drill bit 110 is less than 120%, it is determined that drill bit 110 has not interfered with the reinforcement in the concrete wall, and drilling can continue.

[0047] Next, we will explain judgment rule 2.

[0048] In judgment rule 2, the joint load current of each joint 1 to 6 and the tool load current of the drill bit 110 are collected in advance, and these load currents are converted into percentages of their respective rated currents. Then, the average current ratio of each joint 1 to 6 and the drill bit 110 is calculated by formula (3).

[0049] Average current ratio I(average) = Sum(I1, I2, I3......In) / n... Equation (3)

[0050] Where I (average) represents the average current ratio, I1, I2, I3...In represent the percentage of each current to its respective rated current, and n represents the number of data sets, which is a natural number greater than or equal to 1.

[0051] Here, for example, the average current ratio is calculated every 0.5 seconds. Since the previous data collection period was 10 times per second, there are five sets of data each time the average current ratio is calculated, i.e., n=5.

[0052] After calculating the average current ratio of each joint 1-6 and the drill bit 110, it is compared with their respective rated currents to determine whether interference with the reinforcing steel has occurred. Specifically, if any one of the average current ratios of each joint 1-6 and the drill bit 110 exceeds 100%, it is determined that the drill bit 110 has interfered with the reinforcing steel in the concrete wall. If none of the average current ratios of each joint 1-6 and the drill bit 110 exceed 100%, it is determined that the drill bit 110 has not interfered with the reinforcing steel in the concrete wall, and drilling can continue.

[0053] Figure 5 This is a diagram showing the current state of each joint 1 to 6 and the drill bit 110 under the condition of a load surge in an embodiment of the present invention.

[0054] Figure 5 During the time interval between 110 seconds and 190 seconds, the current ratio of joint 6 significantly exceeded 100%. At this point, it can be determined that the drill bit 110 interfered with the steel reinforcement inside the concrete wall, causing the abnormal increase in current at joint 6.

[0055] Next, refer to Figures 6-8 The reinforcement avoidance strategy of the implementation method is explained.

[0056] Figure 6 This is a schematic diagram illustrating the automatic avoidance strategy after contact with reinforcing bars according to an embodiment of the present invention. Figure 7 This is a schematic diagram showing the robot 100 of an embodiment of the present invention tilting in a wall. Figure 8 yes Figure 7 AA-direction cross-section diagram.

[0057] In this embodiment, such as Figure 6 As shown, the methods for avoiding steel bars mainly include two aspects: the first is to try the tilt angle, and the second is to optimize the tilt speed. Figure 7 The image shows the state of the robot 100 tilting the drill bit 110 in the wall.

[0058] First, such as Figure 8 As shown, the drill bit 110 is tilted at an angle θ in the horizontal direction and moved forward. This angle θ can be obtained by the following equation (4).

[0059]

[0060] That is, to find the arctangent function of the ratio of the rebar radius to the length of the drill bit 110.

[0061] Since the reinforcing bars in concrete walls are mostly distributed in a roughly vertical manner, the reinforcing bars can be avoided in most cases by tilting the drill bit 110 at an angle θ in the horizontal direction. The avoidance method is simple and the avoidance angle is reasonable.

[0062] After tilting the drill bit 110 horizontally by an angle θ and advancing it, it is determined whether interference with the reinforcing bar still exists. The specific determination method has been described in detail above and will not be explained here.

[0063] If the interference with the reinforcing steel is still determined at this point, the drill bit 110 is repeatedly tilted clockwise or counterclockwise by, for example, 45° and advanced until the interference with the reinforcing steel is determined to be absent. Specifically, if the absence of interference with the reinforcing steel is determined after the first tilting of the drill bit 110 at 45° clockwise or counterclockwise and advancing, the tilting process ends, and drilling continues. If the presence of interference with the reinforcing steel is still determined after the first tilting of the drill bit 110 at 45° clockwise or counterclockwise and advancing, the drill bit 110 is tilted clockwise or counterclockwise by 45° a second time and advanced until the interference with the reinforcing steel is determined to be absent. Here, although the case of repeatedly tilting the drill bit 110 at 45° is illustrated, it is not limited to this; other specific angles can be repeated, or different angles can be tilted each time.

[0064] Therefore, by trying different tilt angles, the optimal tilt angle can be selected without excessive tilting, thus improving the efficiency of avoiding steel bars.

[0065] In order to reduce the time required to avoid the drill bit 110 and thus improve the efficiency of the drilling operation, this embodiment also performs optimization of the tilting speed during the process of tilting the drill bit 110. That is, when tilting the drill bit 110 for the first time, starting from the lowest speed, such as 1% of the fastest speed at which the robot 100 can tilt the drill bit 110, the tilting speed is gradually increased, and finally the fastest speed that will not cause the robot 100 to be overloaded is selected as the optimal tilting speed.

[0066] Here, the method for determining whether it will cause robot 100 overload is basically the same as the method for determining whether there is steel bar interference mentioned above.

[0067] Specifically, initially, the drill 110 is tilted at the lowest speed. If, during tilting, the rate of increase in load value for each joint 1-6 and the rate of increase in load value for the drill 110 are both less than 120%, or if the average current ratio for each joint 1-6 and the average current ratio for the drill 110 do not exceed 100%, then the tilting speed is increased by a predetermined percentage. This process is repeated until either the rate of increase in load value for each joint 1-6 and the rate of increase in load value for the drill 110 during tilting is greater than or equal to 120%, or either the average current ratio for each joint 1-6 and the average current ratio for the drill 110 exceeds 100%. If, during tilting, the rate of increase in load value for each joint 1-6 and the rate of increase in load value for the drill 110 are greater than or equal to 120%, or either the average current ratio for each joint 1-6 and the average current ratio for the drill 110 exceeds 100%, i.e., the robot 100 is overloaded, the last speed before the robot 100 becomes overloaded is selected as the optimal tilting speed.

[0068] According to this embodiment, the robot can be protected from overload due to steel bar interference, thus avoiding damage to the motor, drill bit, and gears.

[0069] According to this embodiment, it is possible to effectively determine whether there is steel bar interference and immediately avoid it without having to drill holes again, which greatly improves the work efficiency when drilling holes.

[0070] Furthermore, according to this embodiment, by trying a reasonable tilt angle and selecting the optimal tilt speed during the process of avoiding the steel bars, the time spent avoiding the steel bars can be shortened, thereby further improving work efficiency.

[0071] The embodiments of the method for determining and avoiding steel bar interference of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific configuration of the method for determining and avoiding steel bar interference of the present invention is not limited to the above embodiments, and design changes that do not depart from the spirit of the present invention are also included in the present invention.

[0072] Symbol Explanation

[0073] 100: Robot, 110: Drill bit, 120: Current sensor.

Claims

1. A method for determining and avoiding interference from reinforcing bars, implemented by a robot equipped with a drill bit drilling a hole in a wall, characterized in that the method includes the following steps: The joint load current of each joint of the robot and the tool load current of the drill bit are collected. Based on the joint load current and the tool load current, the rate of increase in load value or the average current ratio of each joint and the drill bit during drilling is calculated, thereby determining whether there is interference from reinforcing steel bars inside the wall during drilling. If it is determined that there is interference from reinforcing bars, the drill bit is tilted to avoid the reinforcing bars. When any one of the load value increase rate during drilling of the joints and the drill bit is 120% or more, or when any one of the average current ratios during drilling of the joints and the drill bit exceeds 100%, it is determined that there is reinforcement interference.

2. The method for determining and avoiding interference with reinforcing bars according to claim 1, characterized in that, If it is determined that there is interference from the reinforcing bars, the drill bit is first tilted horizontally and moved forward to determine whether there is still interference from the reinforcing bars. If it is determined that there is still interference from the reinforcing bars, the drill bit is tilted at a specific angle clockwise or counterclockwise and moved forward repeatedly until it is determined that there is no interference from the reinforcing bars.

3. The method for determining and avoiding interference with reinforcing bars according to claim 2, characterized in that, The drill bit is tilted at an angle greater than θ along the horizontal direction, where θ is the arctangent function value of the value obtained by dividing the radius of the reinforcing bar by the length of the drill bit.

4. The method for determining and avoiding interference with reinforcing bars according to claim 2, characterized in that, During the process of tilting the drill bit, the tilting speed is increased sequentially from the lowest speed until a specified condition is met. The last tilting speed before the specified condition is met is selected as the optimal tilting speed. The lowest speed is 1% of the maximum speed at which the drill bit can tilt.

5. The method for determining and avoiding interference with reinforcing bars according to claim 4, characterized in that, The specified conditions are that any one of the load value increase rate when the joints and the drill bit are tilted is 120% or more, or any one of the average current ratios when the joints and the drill bit are tilted exceeds 100%.

6. The method for determining and avoiding interference with reinforcing bars according to claim 1 or 5, characterized in that, The load increase rate is obtained by dividing the current load value by the previous load value before a specified time. The load value of each joint is obtained by dividing the product of the joint load current, the voltage of each joint, and the energizing time by the rotation angle of each joint. The load value of the drill bit is obtained by dividing the product of the tool load current, the working voltage of the drill bit, and the energizing time by the advance distance of the drill bit.

7. The method for determining and avoiding interference with reinforcing bars according to claim 1 or 5, characterized in that, The average current ratio is the average of the joint load current of each joint and the tool load current of the drill bit as a percentage of its rated current over a specified time period.

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