A mobile robot printing job method

Abstract

The application discloses a kind of mobile robot printing job methods, the method is as follows: step 1: start initialization mobile robot, automatically calibrate spray printing head zero, extract the data information of job map;Step 2: determine laser positioning placement position, complete laser positioning equipment leveling, measure and track the position of robot by target ball installed on robot;Step 3: generate automatic job path: select the map to be worked, align reference, map coordinate system mapping to ground work area, edit map to set obstacle information, frame select part or all work range, parameter setting, call path planning algorithm to generate job path and printing process information;Step 4: robot carries out printing job in work area according to job path and printing process information;Printing job is completed, end automatic work flow;The application measures the reflecting device installed at the end of mobile robot by absolute positioning device, realizes the position precision of optimizing mobile robot spray printing positioning.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mobile printing, and particularly relates to a mobile robot printing operation method. BACKGROUND

[0002] The mobile robot with the spray printing function can be applied to various scenes, and is mainly applied to scenarios such as building construction site setting out, factory planning positioning setting out, exhibition venue planning layout, road marking construction, and the like. The present application is a mobile robot for spraying or printing symbols, characters, curves and other designated meaning marks on a plane (for example, a building decoration to be constructed ground, a factory equipment installation ground, an exhibition hall layout ground, a road construction marking ground, and the like).

[0003] The most difficult challenge of such a mobile robot is how to accurately and accurately transfer design information on the plane. In actual engineering applications, the accuracy required by the construction party is generally in the order of centimeters or even millimeters, however, the positioning of the mobile robot is difficult to achieve such accuracy. The commonly used method for positioning the position of the mobile robot in space is to use sensors (usually laser radars) to sense the distance between the robot and the known surrounding environment, i.e. the map (such as walls, columns), and the current top sensor can only achieve centimeter-level positioning accuracy. Even in the case of repeated optimization of mapping, positioning algorithms and the like, this limits the positioning ability of the mobile robot. Currently, in the above-mentioned application scenarios, a manual physical marking form is usually used to present the paper design drawing and digitalized requirements on the construction ground. Specifically, in actual operation, engineers manually measure and physically mark, such as measuring the distance of columns and walls, and through the traction of the ink line setting out on the working surface. In this process, a total station instrument is usually used for accurate guidance to improve the operation efficiency and positioning accuracy.

[0004] The absolute positioning device generally realizes high-precision three-dimensional measurement based on light and automatic control technology, and has the characteristics of portability, and is mainly used in the field of large-size space coordinate measurement. Advanced technologies such as laser interference distance measurement and angle measurement are usually used. Based on the measurement principle of spherical coordinate method, the angle and distance are measured to realize accurate measurement of three-dimensional coordinates. At present, in the field of large-size precision measurement, a laser tracker with the advantages of wide measurement range, high precision, multiple functions and on-site measurement is generally used. Through it, many traditional measurement equipment such as large fixed three-coordinate measuring machines, theodolites and total stations can be replaced, and high measurement precision and efficiency are shown in the application fields of device calibration, part detection, tool manufacturing and debugging, integrated assembly and reverse engineering. In the field of precision engineering measurement or deformation monitoring of general large buildings, underground tunnel construction, venue construction and the like, a total station (total station type electronic speed measuring instrument) with functions such as angle measurement, distance (slope distance, horizontal distance, height difference) measurement, three-dimensional coordinate measurement, traverse measurement, intersection point measurement and setting out measurement is widely used. SUMMARY

[0005] The present application aims to design a mobile robot printing operation method, the mobile robot has the function of moving according to the planned arbitrary trajectory in the plane and can delineate the moving trajectory contour.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A mobile robot printing operation method, characterized in that the method is as follows:

[0008] Step 1: start the initialization mobile robot, automatically calibrate the zero position of the spraying print head, and extract the data information of the operation map;

[0009] Step 2: determine the laser positioning placement position, complete the leveling of the laser positioning device, and measure and track the position of the robot through the target ball installed on the robot;

[0010] Step 3: generate an automatic operation path: select the map to be operated, align the reference, map the coordinate system of the map to the ground operation area, edit the map to set the obstacle information, frame part or all of the operation range, set the parameters, call the path planning algorithm to generate the operation path and the printing process information;

[0011] Step 4: the robot performs printing operation in the operation area according to the operation path and the printing process information; after the printing operation is completed, the automatic operation process is ended.

[0012] Further, the mobile printing robot communicates with the terminal, receives and executes the control instructions issued by the terminal, and feeds back the robot state and the automatic operation result; the laser positioning device tracks the positioning target ball on the printing operation robot, measures the coordinates of the current mobile printing robot relative to the laser positioning device, and then sends the position measurement information to the mobile printing robot.

[0013] Further, in step 1, the mobile robot is started, the terminal sends a command to the robot to return the zero position of the print head, and when the zero return action is completed, the control unit automatically notifies the ranging sensor to measure the actual zero position of the print head.

[0014] Further, the control unit performs several measurements and transmits the measurement data into the algorithm module for filtering processing to obtain an accurate measurement value, then calculates the actual zero position deviation and stores it, which can be subtracted or added to the control amount when controlling the movement of the print head in the subsequent operation process, thereby improving the spraying operation precision.

[0015] Further, after starting the three-dimensional measuring device and initializing in step 1, the initial aiming of the reflecting device and the three-dimensional measuring device is completed by manual assistance, after the initial aiming is completed, the mobile robot is started and initialized, and the three-dimensional measuring device sends the measured reflecting device coordinate data to the mobile robot control unit in real time through the wireless communication device, the control unit analyzes and saves the received data, and the analysis and saving are performed when the data is received for the first time, and starting from the second time of receiving data, the rotation angle theta of the adjacent two time points is calculated each time, and finally the reflecting device is rotated by the corresponding angle value to realize the active aiming of the reflecting device to the three-dimensional measuring device.

[0016] Further, the three-dimensional measuring device can actively aim the reflecting device, and the reflecting device reflects the laser beam within ±45℃, so when theta is less than the threshold θ e, the reflecting device is not rotated.

[0017] Further, the method for calculating the rotation angle theta of the adjacent two time points is as follows:

[0018] The vector can be calculated from the coordinates of the reflecting device at A, that is, The vector can be calculated from the coordinates of the reflecting device at B, that is, Further, the cross product vector of the two vectors is calculated:

[0019]

[0020] Then the rotation angle theta can be calculated as:

[0021]

[0022] The result of the vector cross product is a vector, which is defined as positive when the direction thereof is less than 90℃ with the Z axis of the three-dimensional measuring device, and negative when it is greater than 90℃, The direction of the vector is greater than 90℃ with the Z axis of the three-dimensional measuring device, so the value of theta is negative; it is defined as positive when the reflecting device rotates counterclockwise around the central axis, and negative when it rotates clockwise.

[0023] The following beneficial effects can be obtained through the above technical solution:

[0024] The present application measures the reflecting device installed at the end of the mobile robot by using the absolute positioning device, so as to realize the position accuracy of the optimized mobile robot spraying and printing positioning.

[0025] Meanwhile, the present application calculates the actual zero deviation, and subtracts or adds the deviation from the control amount when controlling the movement of the printing head in the subsequent operation process, so as to eliminate the system error and achieve the purpose of improving the operation accuracy.

[0026] The application can realize that the reflection device automatically aims at the three-dimensional measuring device in the robot operation process only through the measuring data of the three-dimensional measuring device, can reduce the cost of the robot, and the method is very simple, and more importantly, the precision is high and there is no cumulative error. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the flow chart of the application.

[0028] Figure 2 is the system composition relationship diagram of the application

[0029] Figure 3 is the schematic diagram of the mobile robot.

[0030] Figure 4 is the coordinate schematic diagram.

[0031] Figure 5 is the schematic diagram of the rotation angle θ. DETAILED DESCRIPTION

[0032] The application will be further described below in combination with the drawings:

[0033] As shown in Figure 1 and 2 , the mobile robot is started, the straight lines (solid lines, dashed lines), circles, curves, symbols, characters, graphics and two-dimensional codes and color data information on the CAD drawing or BIM are extracted, the laser positioning placement position is determined, the laser positioning device is leveled, the position of the robot is measured and tracked through the target ball installed on the robot, the automatic operation path is generated: the map to be operated is selected, the reference is aligned, the map coordinate system is mapped to the ground operation area, the obstacle information is edited, the operation range is selected, the parameter is set, the operation path is generated by calling the path planning algorithm, and the printing process information is printed; the robot performs printing operation in the operation area according to the operation path and the printing process information; the printing operation is completed, and the automatic operation process is ended.

[0034] The automatic operation route can avoid the set obstacles, and the ultrasonic sensor can sense the temporary appearance of people or other objects and pits around the robot in real time during the movement of the robot, stop the obstacles and start the voice alarm.

[0035] Through the operation terminal APP terminal software, the parameters can be set, the robot state, the coordinate position, the movement speed, the angular velocity, the chassis, the cloud platform motor, the horizontal movement motor, the inkjet test, the imported operation data, the generated operation path and the automatic operation task can be controlled.

[0036] Mobile printing robot: The mobile printing robot communicates with the APP, receives and executes the control commands below the APP, and provides feedback on the robot status and automatic operation results; the laser positioning device tracks the positioning target ball on the printing robot, measures the current coordinates of the mobile printing robot relative to the laser positioning device, and then sends the position measurement information to the mobile printing robot.

[0037] like Figure 3 As shown, in the embodiments of this patent, the spraying and printing system mounted on the mobile robot consists of a spraying printhead, a printhead control mechanism, a printhead traversing mechanism, and a distance sensor. During the spraying operation, the mobile robot calculates the position of the printhead in real time based on the received position information and through the algorithm module in the control unit. Finally, the printhead control mechanism drives the spraying printhead to move along the printhead traversing mechanism to achieve precise spraying. As can be seen from the above description, the accuracy of the spraying printhead's movement on the traversing mechanism plays a crucial role in the operational precision.

[0038] like Figure 4 As shown, the robot's own coordinate system is constructed with the center of the two wheels as the origin, the robot's central axis along the forward direction as the X-axis, and the Y-axis defined by the right-hand rule. Figure 4 In the left diagram, L represents the distance from the ranging sensor to the robot's X-axis, and W is defined as the width of the print head. When the mobile robot commands the print head to return to zero, according to design and control principles, the print head should be on the central axis of the mobile robot, i.e., the theoretical zero position. However, in actual operation, robots often have uncontrollable systematic errors, such as manufacturing errors, installation errors, errors caused by transportation vibrations, and wear and tear on parts after long-term operation. If the actual zero position of the print head is not calibrated after the mobile robot executes the zero-return command, and the theoretical zero position is still used, these errors will obviously be introduced into subsequent operations. Figure 4 As shown in the right figure, the actual zero position of the print head has deviated to the right from the centerline. The zero position deviation at this time is:

[0039] e = d - L + w / 2

[0040] Where d is the actual measured value of the ranging sensor.

[0041] When e>0, it means that the actual distance from the printhead zero position to the ranging sensor is greater than the theoretical zero position, and is closer to the negative half-axis of the robot's Y-axis.

[0042] When e < 0, it means that the actual distance from the print head zero position to the ranging sensor is smaller than the theoretical zero position, and is closer to the positive half-axis of the robot's Y-axis.

[0043] After the mobile robot is started, the portable computing device can send a command to the robot to zero the print head. When the zeroing action is completed, the control unit automatically instructs the ranging sensor to measure the actual zero position of the print head. Since the sensor often has measurement noise, the control unit will instruct to take multiple measurements and pass the measurement data into the algorithm module for filtering to obtain a more accurate measurement value, and then further calculate the actual zero position deviation and store it. In the subsequent work process, the control amount can be reduced or added to the control amount when the print head is controlled to move, thereby improving the spraying work precision.

[0044] Figure 5 As shown, it is assumed that the reflecting device at position A of the mobile robot has been accurately aimed, i.e., the laser beam (indicated by a dashed line) emitted by the three-dimensional measuring device can be accurately reflected by the reflecting device. When the mobile robot moves from position A to position B along an arbitrary trajectory, the reflecting device has a large positional change around the origin of the three-dimensional measuring device, thereby causing a change in the mutual aiming direction between the reflecting device and the three-dimensional measuring device. In order to enable the three-dimensional measuring device to quickly and accurately track the position of the reflecting device, the present application actively controls the reflecting device to rotate by an angle θ so that it is always directed toward the origin of the three-dimensional measuring device. The calculation method of the rotation angle θ is as follows:

[0045] Vector The coordinates of the reflecting device at A can be calculated as follows: Vector The coordinates of the reflecting device at B can be calculated as follows: Further calculate the cross product vector of the two vectors:

[0046]

[0047] The rotation angle θ can be calculated as follows:

[0048]

[0049] The result of the vector cross product is a vector, and the present application defines it as positive when the direction thereof makes an angle of less than 90° with the Z axis of the three-dimensional measuring device, and negative when the angle is greater than 90°. As shown in the case in Figure 5 , the direction of makes an angle of greater than 90° with the Z axis of the three-dimensional measuring device, so the value of θ is negative. The present application defines that the clockwise rotation of the reflecting device around the central axis thereof is positive, and the counterclockwise rotation is negative, Figure 5 In the case shown in , θ is negative, so the reflecting device is controlled to rotate clockwise by the corresponding angle value to actively aim at the origin of the three-dimensional measuring device.

[0050] From the above calculation equation, the method has the advantages of simple calculation, numerical stability, no cumulative error, no dependence on any other sensor and no need to consider the motion trajectory of the robot, and has the value of application in the scene of positioning the mobile robot through the three-dimensional device and the reflecting device.

[0051] The specific solution is that after starting and initializing the three-dimensional measuring device, the initial aiming of the reflecting device and the three-dimensional measuring device is completed by manual assistance. After starting and initializing the mobile robot, the three-dimensional measuring device sends the measured reflecting device coordinate data to the mobile robot control unit in real time through the wireless communication device. The control unit analyzes and saves the received data, and analyzes and saves it for the first time. Starting from the second time of receiving data, the rotation angle θ of the adjacent two time points is calculated through the above equation each time. Finally, the reflecting device can be actively aimed at the three-dimensional measuring device by controlling the reflecting device to rotate the corresponding angle value. Further, since the three-dimensional measuring device can actively aim at the reflecting device, and the reflecting device reflects the laser beam within ±45°, when |θ| is less than the threshold value θ e (must be less than 45°), the reflecting device can not be rotated.

[0052] Only through the measurement data of the three-dimensional measuring device, the reflecting device can automatically aim at the three-dimensional measuring device during the operation of the robot, which can reduce the cost of the robot, and the method is very simple, more importantly, the precision is high and there is no cumulative error. The present application comprises a mobile robot, a three-dimensional measuring device, a three-dimensional measuring device such as a total station, a tracking instrument, a position monitoring device, etc. The three-dimensional measuring device irradiates the device with reflecting function on the mobile robot by emitting laser beam, and the device with reflecting function is fixed on the mobile robot, so that the position of the reflecting device can be reflected in real time. The above connection mode is not limited to detachable or permanent fixation mode. The measurement information collected by the three-dimensional measuring device is transmitted to the mobile robot in a wireless manner, such as WIFI, radio wave, optical method, etc. The transmission of measurement information needs to have low delay and low packet loss rate, i.e. real-time and accuracy of transmission. Low delay can ensure that the mobile robot responds in time and quickly, and accuracy can ensure that the trajectory of the mobile robot tends to be the theoretical value.

[0053] The above-mentioned are preferred embodiments of the present application, and for those skilled in the art, various equivalent modifications of the present application without departing from the principles of the present application are within the protection scope of the appended claims of the present application.

Claims

1. A method of robotic print job, characterized by: The method is as follows: Step 1: start the initialization mobile robot, automatically calibrate the spray printing head zero position, and extract data information of the work map; Step 2: determine the laser positioning placement position, complete the laser positioning equipment leveling, and measure and track the position of the robot through the target ball installed on the robot; Step 3: generate an automatic work path: select the map to be worked, align the reference, map the coordinate system to the ground work area, edit the map to set the obstacle information, frame the partial or whole work range, set the parameters, call the path planning algorithm to generate the work path and the printing process information; Step 4: the robot performs printing work in the work area according to the work path and the printing process information; after the printing work is completed, the automatic work process is ended; After the three-dimensional measuring device is started and initialized in step 1, the initial aiming of the reflecting device and the three-dimensional measuring device is completed by manual assistance, after the mobile robot is started and initialized, the three-dimensional measuring device sends the measured reflecting device coordinate data to the mobile robot control unit in real time through the wireless communication device, the control unit analyzes and saves the received data, the analysis and saving are performed at the first time of receiving data, and from the second time of receiving data, the rotation angles of adjacent two time points are calculated each time , and finally the reflecting device is rotated by the corresponding angle value to realize the active aiming of the three-dimensional measuring device by the reflecting device. The three-dimensional measuring device can actively aim the reflective device, and the reflective device reflects the laser beam within ±45°, and when less than a threshold the reflective device is not rotated. calculating the rotation angle for two adjacent time instants The method is as follows: Vector The coordinates at A can be calculated from the reflection device, i.e. ; Vector The coordinates at B can be calculated from the reflection device, i.e. ; Further calculate the cross product vector of the two vectors ； The rotation angle can be calculated as is: ； The result of the vector cross product is a vector defined as positive when its direction makes an angle with the Z axis of the three-dimensional measuring device of less than 90° and negative when it makes an angle greater than 90°, is a vector defined as positive when its direction makes an angle with the Z axis of the three-dimensional measuring device of less than 90° and negative when it makes an angle greater than 90°, is a vector defined as positive when its direction makes an angle with the Z axis of the three-dimensional measuring device of less than 90° and negative when it makes an angle greater than 90°, 2. The method of claim 1, wherein: The mobile printing robot communicates with the terminal, receives and executes the control instructions issued by the terminal, and feeds back the robot state and the automatic work result; the laser positioning device tracks the positioning target ball on the printing work robot, measures the coordinates of the mobile printing robot relative to the laser positioning device, and then sends the position measurement information to the mobile printing robot.

3. The method of claim 1, wherein: In step 1, the mobile robot is started, the terminal sends a command to the robot to return the printing head to zero, and when the zero return action is completed, the control unit automatically notifies the ranging sensor to measure the actual zero position of the printing head.

4. The method of claim 3, wherein: The control unit performs several measurements and transmits the measurement data into the algorithm module for filtering processing to obtain an accurate measurement value, then calculates the actual zero position deviation and stores it, and in the subsequent work process, the control amount can be reduced or added to the control amount when the printing head moves, thereby improving the spraying work precision.

5. The method of claim 1, wherein: The data information includes one or more combinations of straight lines, circles, curves, symbols, characters and colors.

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