Portable printing and copying machine with autonomous movement and multi-machine cooperation functions

Abstract

The invention provides a portable printing and copying machine device with autonomous movement and multi-machine cooperation functions, which is characterized in that a, one or more printing nozzles are arranged to support printing images on the surface of a printing medium; the feature b is that one or more contact image sensors are arranged and are used for acquiring an image of the surface of a printing or scanning medium; c, a selectable motion tracking sensor is arranged and used for measuring local relative motion of the printing and copying machine in the printing or scanning process; d, an autonomous moving device with a three-degree-of-freedom motion capability in a plane is arranged, so that the printing and copying machine autonomously moves on the surface of the medium to complete printing or scanning operation; and e, a wireless communication module is arranged and is used for receiving a printing task or communicating with other portable printing and copying machines. According to the invention, the manual operation is reduced in the splicing type printing or scanning operation, and the working efficiency is high; the machine is compact and light in structure and flexible in use mode, and printing and scanning sizes are not limited.

Description

[Technical Field]

[0001] This invention relates to a printer / copier, and more particularly to a portable printer / copier with autonomous mobility and multi-machine collaboration capabilities. [Background Technology]

[0002] Existing vision-based portable printers support the stitching and printing of images of any size, offering great flexibility. However, manual operation is inefficient, primarily because they do not support autonomous movement on the printing or scanning media plane, nor do they support multi-machine collaborative parallel operation. For example, patent application 202110482240.X discloses a vision-based positioning method for portable printers and copiers, achieving high-precision positioning; patent application 202311474966.4 discloses a method for improving printing positioning accuracy using a linear image sensor and a preset marking pattern on the printing media surface.

[0003] Therefore, the working efficiency of portable printers and copiers based on visual positioning principles remains a bottleneck. The main problem this invention addresses is how to improve the working efficiency of portable printers and copiers without affecting the accuracy of splicing printing and scanning. [Summary of the Invention]

[0004] This invention realizes a portable printer / copier based on the principle of visual positioning, which features high working efficiency and high printing accuracy. This portable printer / copier has the ability to autonomously position, move, and operate on the printing or scanning media plane. It has a compact and lightweight structure, and its printing size is not limited, greatly expanding the applicability of portable printers / copiers. The specific technical solution is as follows.

[0005] This invention proposes a portable printing and copier device with autonomous mobility and multi-machine collaboration capabilities, characterized by:

[0006] Feature a: It has one or more printheads that support printing images onto the surface of the printing medium.

[0007] Feature b: Equipped with one or more contact image sensors for acquiring images of the printed or scanned media surface.

[0008] Feature c: Equipped with an optional motion tracking sensor for measuring local relative motion of the printer or copier during printing or scanning.

[0009] Feature d: It is equipped with an autonomous moving device with three degrees of freedom in the plane, which enables the printer / copier to move autonomously on the media surface to complete printing or scanning operations.

[0010] Feature e: Equipped with a wireless communication module for receiving print jobs or communicating with other portable printers and copiers.

[0011] Furthermore, in printing or scanning tasks, the portable printer / copier is positioned using the image obtained by the contact image sensor set in feature b, thereby obtaining its position and angle in the printing or scanning medium, and thus realizing splicing printing or splicing scanning.

[0012] Furthermore, the contact image sensor in feature b is replaced with a line scan camera or an area scan camera for image data acquisition. If a line scan camera or an area scan camera is used, its imaging model needs to be calibrated, and then a distortion-free image of the printed or scanned media surface is obtained based on the imaging model parameters and the original acquired image. If a line scan camera or an area scan camera is used, the camera is set to image only a local area at the bottom of the portable printer / copier, thereby overcoming the positioning error caused by unevenness or warping of the printing media and improving the positioning accuracy of the print head in the printing media. Optionally, if an area scan camera is used, its imaging area (ROI) is set so that it only images the media surface within a specific angular range in the camera sensor coordinate system, thereby further improving the camera frame rate, reducing computational resource consumption, shortening processing latency, and improving positioning accuracy. All content related to contact image sensors in the following text applies to line scan cameras or area scan cameras.

[0013] Furthermore, the motion tracking sensor in feature c refers to a wheel speed measuring device, stepper motor, encoder, magnetic grating sensor, capacitive grating sensor, optical grating sensor, mouse sensor, or IMU. Optional motion tracking sensors possess one to three degrees of freedom for measuring local relative motion, supporting the measurement of the lateral, longitudinal, and / or rotational amounts of the printer / copier on the media plane over short periods, thereby improving tracking and positioning accuracy.

[0014] Furthermore, feature d provides autonomous movement capabilities that enable the portable printer / copier to move in three degrees of freedom within a plane, including lateral movement, longitudinal movement, and rotation on the media plane, as well as combined movements of these three motions. This flexible autonomous movement capability improves the efficiency of the portable printer / copier.

[0015] Furthermore, the autonomous movement device in feature d includes an omniwheel or mecanum wheel, or other type of wheel-like device with adjustable relative speed direction and magnitude to the medium, driven by an electric motor. If only omniwheels or mecanum wheels are used, there are at least three omniwheels or mecanum wheels arranged in at least two groups, with the wheel type and drive shaft direction being the same in each group, and each group having at least one wheel. The omniwheel is a combination of sub-rolling elements arranged circumferentially, with the axis of the sub-rolling elements in the circumferential plane, enabling it to roll simultaneously in a direction parallel or perpendicular to the circumferential plane. The mecanum wheel is a combination of sub-rolling elements arranged circumferentially, with the axis of the sub-rolling elements at a 45-degree angle to the circumferential plane, enabling it to obtain a pushing force at a 45-degree angle to the circumferential plane.

[0016] Furthermore, feature d includes an autonomous moving device with two operating modes: manual operation and autonomous operation. In manual operation mode, the portable printer / copier is manually moved across the printing or scanning media to complete splicing printing or image scanning tasks. During this mode, the autonomous moving device retracts its wheels to prevent them from contacting the printing or scanning media, or disconnects the motor from the wheels via a clutch, or the motor remains inactive, thus generating no driving force. In autonomous operation mode, the portable printer / copier moves autonomously across the printing or scanning media to complete splicing printing or image scanning tasks. During this mode, the autonomous moving device releases its wheels to contact the printing or scanning media, or connects the motor to the wheels via a clutch, causing the motor to operate and generate driving force. This ability to freely switch between manual and autonomous operation modes makes the portable printer / copier more flexible in its use.

[0017] Furthermore, the wireless communication module in feature e is an electronic device that transmits and receives data via radio waves, including 4G, 5G, WLAN, Bluetooth, ZigBee, LoRa, or NB-IoT devices. The client terminal used for communication and the portable printer / copier, as well as different portable printers / copiers, support the same or compatible communication and printing protocols. Multiple portable printers / copiers supporting autonomous movement, positioning, and printing share printing information via wireless communication to collaboratively complete a printing task.

[0018] Portable printers and copiers support autonomous stitching printing. The motion planning and control methods for portable printers and copiers in autonomous stitching printing jobs are as follows:

[0019] Step a1: Start the print job and set the data to be printed and its location or range information.

[0020] Step a2: Divide the printing area into multiple passes according to the printing position or range set in step a1 and the single print width of the print head.

[0021] Step a3: The portable printer / copier uses the set sensor data to perform autonomous positioning, and obtains the real-time position, angle, angular velocity and / or velocity of the contact image sensor in the coordinate system of the printing medium.

[0022] Step a4: For each printing area, the portable printer / copier, based on the real-time positioning result obtained in step a3, uses the autonomous moving device set in step d to perform a three-degree-of-freedom composite motion to move the printer to a certain end position of that printing area, and then autonomously moves and prints according to the preset trajectory of that printing area.

[0023] Step a5: Support reciprocating or spiral printing for different passes to shorten the travel path of the portable printer / copier and improve printing efficiency.

[0024] Portable printers and copiers support autonomous stitching scanning. The motion planning and control methods for portable printers and copiers during autonomous stitching scanning operations are as follows:

[0025] Step b1: The portable printer / copier uses the set sensor data to perform autonomous positioning, and obtains the real-time position, angle, angular velocity and / or velocity of the contact image sensor in the scanned image coordinate system.

[0026] Step b2: In the first scan, based on the positioning results of step b1 and through the autonomous moving device set in step d, control the portable printer / copier to move and scan the image along the boundary direction of the scanned image or in any fixed direction.

[0027] Step b3: In non-first scans, based on the positioning results of step b1 and through the autonomous moving device set in step d, the portable printer / copier is controlled to move and scan images in a way that stitches them with previously scanned images. This ensures that new areas are scanned while maintaining a certain overlap with the already scanned areas, thus meeting the requirements for stitching adjacent scanned images.

[0028] Step b4: Support reciprocating or spiral scanning for different passes, shortening the travel path of portable printers and copiers and improving scanning efficiency.

[0029] Portable printers and copiers support multi-machine collaborative autonomous mobile printing, enabling multiple machines to work together in parallel to complete the same printing task and improve printing efficiency. The process of multi-machine collaborative autonomous mobile printing is as follows:

[0030] Step c1: Team up the multiple portable printers and copiers involved in the printing process.

[0031] Step c2: Create a multi-machine collaborative autonomous mobile printing task, and set the data to be printed and the printing range on the printing media.

[0032] Step c3: Distribute the print data and range information to each portable printer / copier.

[0033] Step c4: Each portable printer / copier plans a different printing path, which together cover the entire printing area.

[0034] Step c5: During the printing process, each portable printer / copier performs autonomous positioning to obtain real-time positioning information in the same printing media coordinate system.

[0035] Step c6: During the printing process, multiple portable printers and copiers communicate in real time, share real-time positioning and / or printed area information, and control the portable printers and copiers to move and print through the autonomous moving device set in step d, ensuring that the printed areas of different passes are seamlessly joined and have no (or minimal) repetition, and that different printers and copiers do not collide.

[0036] Furthermore, in multi-machine collaborative autonomous mobile printing tasks, different portable printers and copiers print layers of different colors, thereby reducing the number of colors printed by a single printer, making a single printer more compact, and meeting the color requirements of the printed content.

[0037] In autonomous stitching printing, autonomous stitching scanning, or multi-machine collaborative autonomous mobile printing tasks, one method for portable printers and copiers to autonomously move using an autonomous moving device based on real-time positioning results is as follows:

[0038] Step d1: The portable printer / copier autonomously plans its movement trajectory, including the position, angle, speed and / or angular velocity of the contact image sensor in the printing or scanning coordinate system, wherein the printing or scanning coordinate system is a 2D coordinate system established based on the printing medium or scanned image.

[0039] Step d2: Based on the autonomous positioning results, obtain the real-time position, angle, speed, and / or angular velocity information of the contact image sensor in the printing or scanning coordinate system.

[0040] Step d3: The tracking error is obtained by subtracting the target state of the contact image sensor in the planned trajectory set in step d1 from the real-time positioning state of the contact image sensor obtained in step d2.

[0041] Step d4: Based on the tracking error obtained in step d3 and the kinematics of the autonomous mobile device, calculate and output the control quantities of different actuators in the autonomous mobile device to enable the portable printer / copier to generate a three-degree-of-freedom composite motion and reduce the tracking error.

[0042] Step d5: For different time steps, iteratively execute steps d2-d4 until the planned trajectory set in step d1 is completed.

[0043] Furthermore, in step d4, the method for calculating the control quantities of different actuators in the autonomous mobile device based on the tracking error is the PID algorithm.

[0044] Furthermore, in step d5 of the autonomous mobile scanning task, an image is acquired by a contact image sensor to detect whether the portable printer / copier has reached the boundary of the scanning medium in order to determine whether the planned trajectory has been completed.

[0045] The portable printer / copier proposed in this invention, featuring autonomous movement and multi-machine collaboration, offers the following advantages over existing technologies: The portable printer / copier effectively combines autonomous positioning and movement devices, supporting multi-degree-of-freedom autonomous movement and motion planning control. This reduces manual operation in splicing printing or scanning jobs, resulting in high work efficiency. The machine has a compact and lightweight structure, offering flexible usage and unrestricted printing and scanning sizes. Multi-machine collaboration further enhances work efficiency, providing an effective method for printing single-page ultra-large-area images (e.g., 100 meters by 300 meters) at low cost. This lays the technological foundation for the widespread adoption of vision-based portable printers / copiers. [Attached Image Description]

[0046] Figure 1 This is a schematic diagram of a portable printer / copier with four Mecanum wheels.

[0047] Figure 2 This is a schematic diagram showing the relationship between a contact image sensor and the motion control of a Mecanum wheel.

[0048] Figure 3 This is a schematic diagram of a portable printer / copier with four omnidirectional wheels.

[0049] Figure 4 This is a schematic diagram of a portable printer / copier with three omnidirectional wheels.

[0050] Figure 5 This is a schematic diagram showing the relationship between the contact image sensor and the omnidirectional wheel motion control.

[0051] Figure 6 This is a schematic diagram of a portable printer / copier that uses an area scan camera.

[0052] Figure 7 This is a schematic diagram of a portable printer / copier that uses a Mecanum wheel and an encoder as motion tracking sensors.

[0053] Figure 8 This is a schematic diagram showing the relationship between a contact image sensor and the motion measurement of a Mecanum wheel.

[0054] Figure 9 This is a schematic diagram of a portable printer / copier that uses an omnidirectional wheel and an encoder as motion tracking sensors.

[0055] Figure 10 This is a schematic diagram showing the relationship between a contact image sensor and the motion measurement of an omnidirectional wheel.

[0056] Figure 11 This is a schematic diagram of a reciprocating autonomous printing / scanning path for a portable printer / copier implemented in this invention.

[0057] Figure 12 This is a schematic diagram of a spiral-type autonomous printing / scanning path for a portable printer / copier implemented in this invention.

[0058] Figure 13 This is a schematic diagram of the first-line scanning process of the portable printer / copier that enables autonomous mobile scanning according to the present invention.

[0059] Figure 14 This is a schematic diagram of a non-first-line scanning process of the portable printer / copier that enables autonomous mobile scanning according to the present invention.

[0060] Figure 15 This is a schematic diagram of the multi-machine collaborative autonomous mobile printing method implemented by the present invention. Figure 1 .

[0061] Figure 16 This is a schematic diagram of the multi-machine collaborative autonomous mobile printing method implemented by the present invention. Figure 2 .

[0062] The labels in the diagram are explained as follows:

[0063] 11 Mecanum wheel 12 Printer nozzle 13 Laser mouse sensor

[0064] 14 Inertial Measurement Unit 15 Contact Image Sensor 16 Omnidirectional Wheel

[0065] 17-area array camera imaging range; 18 Mecanum wheels with encoders.

[0066] 19 Omnidirectional wheels with encoders

Detailed Implementation Methods

[0067] A portable printing and copier device with four Mecanum wheels, implemented according to the present invention, is as follows: Figure 1As shown. The portable printer / copier features four Mecanum wheels 11, each driven by an independent motor, directly contacting the printing or scanning media surface. These four Mecanum wheels support lateral, longitudinal, and rotational movements, as well as combinations of these three degrees of freedom. Two printheads 12 are provided, with their nozzles placed parallel to the printing media surface at a 1mm interval, facilitating direct printing of data onto the media surface. A laser mouse sensor 13, parallel to the media surface and 1mm apart, is located at the bottom of the portable printer / copier to measure its two-degree-of-freedom translational motion. An inertial measurement unit 14 is fixedly mounted on the portable printer / copier to measure its rotational motion on the media surface. A contact image sensor 15, in direct contact with the media surface, is located at the bottom of the portable printer / copier to acquire a 1:1 scale image of the media surface.

[0068] In autonomous stitching scanning, the portable printer / copier achieves autonomous movement on the scanning medium surface by driving the Mecanum wheel 11, while simultaneously acquiring data from the laser mouse sensor 13, inertial measurement unit 14, and contact image sensor 15. Using this sensor data, the relative motion for a single pass and the relative pose relationship between multiple passes at different times are estimated to obtain the multi-pass stitching trajectory of the portable printer / copier. Finally, the data from the contact image sensor 15 is stitched together to obtain the final complete scanned image.

[0069] In autonomous stitching printing operations, the portable printer / copier achieves autonomous movement on the printing media surface by driving the Mecanum wheels 11, while simultaneously acquiring data from the laser mouse sensor 13, inertial measurement unit 14, and contact image sensor 15. The relative motion of the portable printer / copier within a short time is estimated using the sensor data. The absolute positioning information of the portable printer / copier in the printing media coordinate system is obtained by stitching the data from the contact image sensor 15 with the image of the printing media surface. These results are then fused to obtain the real-time continuous positioning state of the portable printer / copier, which is used to calculate the position of the print head 12 and print data according to the positioning result. Furthermore, the rotation speed of the four Mecanum wheels 11 is controlled based on the real-time positioning result of the portable printer / copier, causing it to move along a preset printing trajectory.

[0070] In autonomous scanning or printing operations on A3-sized media, an autonomous moving device with four Mecanum wheels controls the motion of a portable printer / copier based on real-time positioning results and target position. An example of this process is as follows: First, the motion trajectory of the contact image sensor is planned based on its initial pose and the pose at the target position. The position, velocity, angle, and angular velocity of the contact image sensor at different times during autonomous movement are set. One motion trajectory planning method is linear interpolation, which plans the motion trajectory based on uniform translation and rotation. Then, the positioning results of the contact image sensor are acquired every 20 milliseconds, including its position, angle, velocity, and angular velocity on the scanning or printing media plane. These results are compared with the expected state of the planned motion trajectory, and the difference is calculated to obtain the trajectory tracking error. Then, a PID algorithm is used to calculate the expected translation and rotation angle of the contact image sensor in the scanning or printing coordinate system between adjacent clock cycles or before the next clock cycle. These are then divided by the clock cycle length (20 milliseconds) to obtain the translational velocity and angular velocity control values. Then, based on the positioning status of the contact image sensor, the translational speed and angular velocity control values ​​are converted to the contact image sensor coordinate system. Finally, the translational speed and angular velocity control values ​​in the contact image sensor coordinate system are converted into the rotational speed of each Mecanum wheel, thereby controlling the corresponding motor to complete the motion execution. The method for calculating the Mecanum wheel rotational speed based on the translational speed and angular velocity control values ​​of the contact image sensor is as follows: Figure 2 As shown, the Mecanum wheel whose rotational speed needs to be controlled is denoted as mcn; establish the 2D coordinate system of the contact image sensor and the 2D coordinate system of the Mecanum wheel, with the spatial parameters between them as follows: This represents the transformation relationship of the coordinates of the same point in the two coordinate systems mentioned above (e.g., the 2D coordinates of point a in the coordinate system of a contact image sensor). 2D coordinates in the Mecanum wheel coordinate system satisfy in, Let be a 2D rotation matrix representing the rotation relationship between two coordinate systems. Let be a 2D vector representing the translation relationship between two coordinate systems. The known quantity is obtained through parameter calibration or the spatial structure of a portable printer / copier; the value of the translational speed control quantity of the contact image sensor in its own coordinate system is... (Two-dimensional vector), angular velocity control quantity is (Scalar); The unit vector along the axis of the rolling element on the Mecanum wheel is The value in the Mecanum wheel coordinate system is The Mecanum wheel controls the rotational speed in the direction of its coordinate axis y. mcn The direction, and the magnitude of the output rotational speed to be solved are... The value of the overall moving speed of the Mecanum wheel relative to the scanning or printing media in its own coordinate system is (Two-dimensional vector). Based on the spatial relationship between the contact image sensor coordinate system and the Mecanum wheel coordinate system, we have:

[0071]

[0072] in, Furthermore, based on the structure of the Mecanum wheel itself, the following features are provided:

[0073]

[0074] Here, · represents the vector dot product operation. Therefore, the required rotational speed of the Mecanum wheel is:

[0075] vc mcn =vx mcn +vy mcn

[0076] A portable printer / copier with four omnidirectional wheels, implemented according to the present invention, achieves the following: Figure 3 As shown, a portable printer / copier is equipped with four omnidirectional wheels 16. These wheels are arranged orthogonally along their axes in two groups, with two wheels in each group. Each omnidirectional wheel 16 is driven by an independent motor. By controlling the rotational speed of these four omnidirectional wheels 16 via motors, the portable printer / copier can achieve lateral movement, longitudinal movement, rotational movement, and combinations of these three degrees of freedom on the media plane. For example, when the rotational speeds of the left and right omnidirectional wheels are greater than zero and the same, and the rotational speeds of the top and bottom omnidirectional wheels are equal to zero, the portable printer / copier moves vertically (longitudinal movement). Similarly, when the rotational speeds of the top and bottom omnidirectional wheels are greater than zero and the same, and the rotational speeds of the left and right omnidirectional wheels are equal to zero, the portable printer / copier moves horizontally (lateral movement).

[0077] A portable printer / copier with three omnidirectional wheels, implemented according to the present invention, is as follows: Figure 4 As shown. Its advantages include a more compact structure, lower cost, and still maintaining three degrees of freedom of motion in the plane. The more compact structure allows portable printers and copiers to print over a larger area even with limited range of motion, reducing the space near the boundaries that cannot be printed.

[0078] In autonomous scanning or printing operations on A3-sized media, an autonomous moving device with three omnidirectional wheels controls the motion of a portable printer / copier based on real-time positioning results and target position. An example of this process is as follows: First, the motion trajectory of the contact image sensor is planned based on its initial pose and the pose at the target position. The position, speed, angle, and angular velocity of the contact image sensor at different times during autonomous movement are set. One motion trajectory planning method is linear interpolation, which plans the motion trajectory based on uniform translation and rotation. Then, the positioning results of the contact image sensor are acquired every 20 milliseconds, including its position, angle, speed, and angular velocity on the scanning or printing media plane. These results are compared with the expected state of the planned motion trajectory, and the difference is calculated to obtain the trajectory tracking error. Then, a PID algorithm is used to calculate the expected translation and rotation angle of the contact image sensor in the scanning or printing coordinate system between adjacent clock cycles or before the next clock cycle. These are then divided by the clock cycle length (20 milliseconds) to obtain the translation speed and angular velocity control values. Then, based on the positioning status of the contact image sensor, the translational speed and angular velocity control values ​​are converted to the contact image sensor coordinate system. Finally, the translational speed and angular velocity control values ​​in the contact image sensor coordinate system are converted into the rotational speed of each omnidirectional wheel, thereby controlling the corresponding motor to complete the motion execution. The method for calculating the omnidirectional wheel rotational speed based on the control values ​​is as follows: Figure 5 As shown, the omni-axis wheel whose rotational speed needs to be controlled is omni; establish the 2D coordinate system of the contact image sensor and the 2D coordinate system of the omni-axis wheel, with the spatial parameters between them as follows: This represents the transformation relationship of the coordinates of the same point in the two coordinate systems mentioned above (e.g., the 2D coordinates of point a in the coordinate system of a contact image sensor). 2D coordinates in the omnidirectional wheel coordinate system satisfy in, Let be a 2D rotation matrix representing the rotation relationship between two coordinate systems. Let be a 2D vector representing the translation relationship between two coordinate systems. The known quantity is obtained through parameter calibration or the spatial structure of a portable printer / copier; the value of the translational speed control quantity of the contact image sensor in its own coordinate system is... (Two-dimensional vector), angular velocity control quantity is (Scalar); the direction of the omnidirectional wheel's control speed is its coordinate axis y. omni The direction, the unit vector of which is The value in the omnidirectional wheel coordinate system is (0,1), and the magnitude of the output rotational speed to be solved is... The overall moving speed of the omnidirectional wheel relative to the scanning or printing media in its own coordinate system is [value]. (Two-dimensional vector). Based on the spatial relationship between the coordinate system of the contact image sensor and the coordinate system of the omnidirectional wheel, we have:

[0079]

[0080] in, Furthermore, based on the structure of the omnidirectional wheel itself, the following features are provided:

[0081]

[0082] Where · represents the vector dot product operation. Therefore, the required output speed of the omnidirectional wheel is:

[0083] vc omni =vy omni

[0084] A portable printer / copier using an area scan camera, as implemented according to the present invention, is shown below. Figure 6 As shown, the area scan camera is installed inside the upper part of the portable printer / copier and supports the acquisition of images of the media surface. To reduce invalid image areas and improve the image frame rate, the imaging area (ROI) 17 of the area scan camera is set so that it only images the printing or scanning media in a local area at the bottom of the portable printer / copier. This setting also ensures that the imaging area and the printing area are on the same plane during the printing task, reducing positioning errors caused by uneven or warped media. Before using the area scan camera for image scanning and positioning, calibration is required to obtain the imaging model parameters of the area scan camera and the spatial relationship between the area scan camera and the media plane. Then, the calibration results are used to distort the original image data and perform homography transformation to obtain a 1:1 scale distortion-free image of the media plane, which replaces the data from the contact image sensor for image acquisition and positioning.

[0085] A portable printer / copier according to the present invention uses an encoder and a Mecanum wheel as motion tracking sensors, such as... Figure 7 As shown. It includes four Mecanum wheels 18 with encoders, which are used to measure the speed of the Mecanum wheels rotating circumferentially. Figure 8 The kinematic relationship between the contact image sensor and the Mecanum wheel in the above device is illustrated. A 2D coordinate system is established for both the contact image sensor and the Mecanum wheel, with the spatial parameters between them as follows: This expresses the transformation relationship of the coordinates of the same point in the two coordinate systems mentioned above (e.g., the 2D coordinates of point a in the coordinate system of a contact image sensor). and 2D coordinates in the Mecanum wheel coordinate system satisfy in, Let be a 2D rotation matrix representing the rotation relationship between two coordinate systems. Let be a 2D vector representing the translation relationship between two coordinate systems. The known quantities are obtained through parameter calibration or the spatial structure of a portable printer / copier. It is the speed at which the contact image sensor moves within its own coordinate system. These are the rotational angular velocities of the contact image sensor; these two quantities represent the local or instantaneous motion information to be solved. The unit vector along the axial direction of the rolling element on the Mecanum wheel is... The value in the Mecanum wheel coordinate system is The main body of the Mecanum wheel rotates in the direction of its coordinate axis y. mcn The direction, and the magnitude of the rotational speed measured by the encoder are: This is the speed at which the Mecanum wheel moves relative to the printing or scanning medium in its own coordinate system. Based on the spatial relationship between the contact image sensor coordinate system and the Mecanum wheel coordinate system:

[0086]

[0087] in, Therefore, according to the Mecanum wheel motion model, we have:

[0088]

[0089] or

[0090]

[0091] Where · denotes the inner product operation of vectors. Let mcn be the four Mecanum wheels on a portable printer / copier. i (i = 0, 1, 2, 3), the extrinsic parameters of the contact image sensor and these four Mecanum wheels are respectively... Furthermore, it is known that the rotational speeds of these four Mecanum wheels, measured by their respective encoders, are as follows: Applying the formula above and solving the system of equations, we get:

[0092]

[0093] Only in the above system of equations and ω cis The unknown quantity is the velocity of the contact image sensor in its own coordinate system, which can be obtained by solving the least-squares solution of the above system of equations. and rotational angular velocity ω cis The value is then used to obtain local or instantaneous motion information of the portable printer / copier.

[0094] A portable printer / copier according to the present invention uses an encoder and an omnidirectional wheel as motion tracking sensors, such as... Figure 9As shown. Among them, there are 3 omnidirectional wheels 19 with encoders, which are used to measure the speed of the omnidirectional wheels in the circumferential direction. Figure 10 The kinematic relationship between the contact image sensor and the omnidirectional wheel in the above device is illustrated. A 2D coordinate system is established for both the contact image sensor and the omnidirectional wheel, with the spatial parameters between them as follows: This expresses the transformation relationship of the coordinates of the same point in the two coordinate systems mentioned above (e.g., the 2D coordinates of point a in the coordinate system of a contact image sensor). and 2D coordinates in the omnidirectional wheel coordinate system satisfy in, Let be a 2D rotation matrix representing the rotation relationship between two coordinate systems. Let be a 2D vector representing the translation relationship between two coordinate systems. The known quantities are obtained through parameter calibration or the spatial structure of a portable printer / copier. It is the speed at which a contact image sensor moves relative to the printing or scanning medium in its own coordinate system. These are the rotational angular velocity of the contact image sensor; these two quantities represent the local or instantaneous motion information to be solved. The rotation direction of the omnidirectional wheel body is its coordinate axis y. omni The direction, the unit vector of which is The value in the omnidirectional wheel coordinate system is (0,1), and the magnitude of the omnidirectional wheel speed measured by the encoder is... This is the speed at which the omnidirectional wheel moves within its own coordinate system. Based on the spatial relationship between the coordinate system of the contact image sensor and the coordinate system of the omnidirectional wheel, we have:

[0095]

[0096] in, Therefore, based on the omnidirectional wheel motion model, we have:

[0097]

[0098] or

[0099]

[0100] Where · denotes the inner product operation of vectors. Let the three omnidirectional wheels on the portable printer / copier be omni... i (i = 0, 1, 2), the external parameter relationships between the contact image sensor and these three omnidirectional wheels are as follows: Furthermore, it is known that the rotational speeds of these three omnidirectional wheels, measured by their respective encoders, are as follows: Applying the formula above and solving the system of equations, we get:

[0101]

[0102] Only in the above system of equations and ω cis The unknown quantity is the velocity of the contact image sensor in its own coordinate system, which can be obtained by solving the above system of equations. and rotational angular velocity ω cis This allows us to obtain information about the local or instantaneous motion of the portable printer / copier.

[0103] The portable printer / copier of this invention supports both manual and autonomous operation modes. One method for automatically switching between these two modes involves connecting the motor and wheels via an electromagnetic clutch. When a discrepancy is detected between the encoder measurement and the motor output, the electromagnetic clutch is disengaged, switching to manual mode. Otherwise, after a period of time or when a new print job is initiated and the encoder speed is zero, the system switches to autonomous operation mode. This automatic switching between manual and autonomous operation modes reduces manual workload, improves printing or scanning efficiency, and protects the motor's lifespan.

[0104] An example of a reciprocating autonomous printing / scanning path for a portable printer / copier according to the present invention. Figure 11 As shown; an example of a spiral-type autonomous printing / scanning path for a portable printer / copier implemented according to the present invention. Figure 12 As shown, reciprocating or spiral motion paths reduce the travel distance of portable printers and copiers during printing or scanning jobs, improving work efficiency. Precise control of the portable printer's position, speed, and angle is required in different motion paths.

[0105] The first-line scanning process of a portable printer / copier with autonomous moving scanning according to the present invention is as follows: Figure 13 As shown. Specifically, the first-line scanning motion is a line-following movement. By acquiring images, the straight-line boundary of the scanning work area is identified and its coordinates are obtained, thereby controlling the portable printer / copier to move along that straight line. The cumulative error in the vertical direction of the portable printer / copier's positioning state along the straight-line boundary is corrected using the straight-line coordinates and the image coordinates of the line (or points on the line), thereby improving positioning accuracy.

[0106] A non-first-line scanning process for autonomous moving scanning in a portable printer / copier according to the present invention is as follows: Figure 14 As shown. Specifically, non-first-line scans employ a stitching-style movement method. By stitching the image with the previous line of scanned images, positioning accuracy is improved.

[0107] A multi-machine collaborative autonomous mobile printing method implemented according to the present invention, such as Figure 15As shown, the printing areas of different portable printers and copiers are adjacent. During the printing process, multiple machines are arranged sequentially along the printing movement direction, each covering a different printing area. Each machine is positioned by scanning the previous printed image, achieving splicing printing and improving work efficiency.

[0108] A multi-machine collaborative autonomous mobile printing method implemented according to the present invention, such as Figure 16 As shown, the printing areas of different portable printers and copiers are isolated. Each portable printer and copier relies on existing markings on the printing medium for positioning and obtains its precise position in the printing medium's coordinate system, thus enabling multiple machines to operate in parallel. This method reduces the complexity of multi-machine collaboration and further improves operational efficiency.

[0109] In the multi-machine collaborative autonomous mobile printing task implemented according to this invention, different printers are responsible for printing layers of different colors. For example, in one instance, two portable printers / copiers collaborate on printing; the first portable printer / copier is responsible for printing black, and the second portable printer / copier is responsible for printing color. In another instance, four portable printers / copiers collaborate on printing, each responsible for printing black, cyan, magenta, and yellow, respectively. The collaborative work of multiple portable printers / copiers makes a single printer more compact and also meets the color expression requirements of the printed content.

[0110] In one implementation of multi-machine collaborative autonomous mobile printing, WLAN or Wi-Fi communication devices are installed on portable printers and copiers, and multiple collaborative portable printers and copiers are all designed according to this invention and support the same printing protocol. Each portable printer and copier has an independent IP address within the wireless local area network (WLAN). Communication between the printing client and the portable printer / copier, as well as between the multiple portable printers and copiers in the group, is conducted via the WLAN. For multiple portable printers and copiers already in a group, printing services are provided externally only through the IP address and port of one of the machines (the master).

[0111] Using multiple portable printers and copiers working together supports printing jobs on large-format media, and the efficiency is several times that of a single machine. In one implementation example, the specific steps for using five portable printers and copiers to collaboratively and autonomously print a 3m by 5m image are as follows:

[0112] Step e1: Team up 5 portable printers and copiers, each with a printhead width of 2 inches (50.8 mm), designate one machine as the master and the other 4 machines as slaves; the master exposes its print service interface to the outside world through the network and waits for print job requests.

[0113] Step e2: Place the 5 portable printers and copiers onto the media to be printed.

[0114] Step e3: The user uses the printing client to initiate a print job request to the master through the network interface, transmitting the image data to be printed and print configuration information, including print resolution (600dpi), size (3 meters by 5 meters), print position range on the printing medium, and printer movement speed (e.g., 20cm / s).

[0115] Step e4: The master receives the print job request, plans the print job (e.g., each printer is responsible for a 3-meter by 1-meter area), and sends the print data and the respective print area to the slave via the Wi-Fi communication device, and issues the instruction to start printing.

[0116] Step e5: The master and slave perform autonomous positioning, plan multiple movement paths according to their respective printing areas, and move the work through autonomous moving devices. During this process, all portable printers and copiers communicate in real time through Wi-Fi communication devices to share information on position, angle, speed, and printed area. Every certain period of time (e.g., 5 seconds), they detect possible collisions and adjust the path planning to avoid duplicate printing and collisions.

[0117] Step e6: The master checks the overall printing progress. After all portable printers and copiers have finished printing in their respective areas, the entire printing task ends, and the client is notified that the printing task is complete.

[0118] In the example above, the efficiency of a single printer is approximately 100 s / m. 2 A single machine takes 25 minutes to print the entire area. However, when five machines collaborate and print in parallel, the entire area is printed in 5 minutes, making the efficiency five times that of a single machine. Therefore, multi-machine collaboration (such as a fleet of more than 500 portable printers and copiers) for autonomous mobile printing is of greater significance for printing ultra-large images (such as 100 meters by 300 meters), as it is an efficient way to achieve this type of printing at low cost.

Claims

1. A portable printing and copier device with autonomous mobility and multi-machine collaboration capabilities, characterized in that, include: Feature a: It is equipped with one or more printheads that support printing images onto the surface of the printing medium; Feature b: Equipped with one or more contact image sensors for acquiring images of the printed or scanned media surface; Feature c: Equipped with an optional motion tracking sensor for measuring local relative motion of the printer or copier during printing or scanning; Feature d: Equipped with an autonomous moving device capable of three degrees of freedom in a plane, enabling the printer / copier to move autonomously on the media surface to complete printing or scanning operations; Feature e: Equipped with a wireless communication module for receiving print jobs or communicating with other portable printers and copiers.

2. The portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 1, characterized in that: In printing or scanning tasks, the portable printer / copier is positioned using the image obtained by the contact image sensor set in feature b, so as to obtain the position and angle in the printing or scanning medium, thereby realizing splicing printing or splicing scanning.

3. A portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 1 or 2, characterized in that: Replace the contact image sensor in feature b with a linear scan camera or an area scan camera for image data acquisition; if a linear scan camera or an area scan camera is used, set the camera to image only a local area at the bottom of the portable printer / copier; alternatively, if an area scan camera is used, set the imaging range ROI so that it only images the surface of the medium within a certain angular range in the camera sensor coordinate system.

4. A portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 1, characterized in that: The motion tracking sensor in feature c refers to a wheel speed measuring device, stepper motor, encoder, magnetic grating sensor, capacitive grating sensor, optical grating sensor, mouse sensor, or IMU; the selected motion tracking sensor has one to three degrees of freedom for measuring local relative motion, supporting the measurement of the lateral movement, longitudinal movement, and / or rotation of the printer / copier on the media plane in a short time, thereby improving tracking and positioning accuracy.

5. A portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 1, characterized in that: The autonomous moving device in feature d supports three degrees of freedom of motion of the portable printer / copier in a plane, including lateral movement, longitudinal movement and rotation on the media plane, as well as combined movements of these three motions.

6. A portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 1 or 5, characterized in that: Furthermore, the autonomous movement device in feature d includes an omnidirectional wheel or a Mecanum wheel driven by a motor, or a wheel-like device whose relative speed direction and magnitude with respect to the medium are adjustable; if only omnidirectional wheels or Mecanum wheels are used, there are at least three omnidirectional wheels or Mecanum wheels arranged in at least two groups, and the wheel type and drive shaft direction are the same in the same group, with at least one wheel in each group; wherein, the omnidirectional wheel is a combination device with sub-rolling elements arranged circumferentially, and the axis of the sub-rolling elements is in the circumferential plane, and the omnidirectional wheel has the ability to roll in a direction parallel or perpendicular to the circumferential plane; the Mecanum wheel is a combination device with sub-rolling elements arranged circumferentially, and the axis of the sub-rolling elements is at a 45-degree angle to the circumferential plane, and the Mecanum wheel has the ability to obtain a pushing force at a 45-degree angle to the circumferential plane.

7. A portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 6, characterized in that: Feature d describes an autonomous mobile device with two operating modes: manual operation and autonomous operation. In manual operation mode, the portable printer / copier is manually moved on the printing or scanning media plane to complete splicing printing or image scanning tasks. In autonomous operation mode, the portable printer / copier moves autonomously on the printing or scanning media plane to complete splicing printing or image scanning tasks.

8. A portable printing and copier device with autonomous movement and multi-machine collaboration functions according to claim 1, characterized in that: Feature e describes a wireless communication module as an electronic device that transmits and receives data via radio waves, including 4G, 5G, WLAN, Bluetooth, ZigBee, LoRa, or NB-IoT devices. The client terminal used for communication and portable printers / copiers, as well as different portable printers / copiers, support the same or compatible communication and printing protocols. Multiple portable printers / copiers that support autonomous movement, positioning, and printing share printing information via wireless communication to jointly complete a printing task.

9. A motion planning and control method for a portable printer / copier device with autonomous movement and multi-machine collaboration functions as described in claim 1 or 5, characterized in that, The steps for self-assembly and printing are as follows: Step a1: Start the print job and set the data to be printed and its location or range information; Step a2: Divide the printing area into multiple passes according to the printing position or range set in step a1 and the single print width of the print head; Step a3: The portable printer / copier uses the sensor data to perform autonomous positioning, obtaining the real-time position, angle, angular velocity and / or velocity of the contact image sensor in the coordinate system of the printing medium; Step a4: For each printing area, the portable printer / copier, based on the real-time positioning result obtained in step a3, uses the autonomous moving device set in step d to perform a three-degree-of-freedom composite motion to move the printer to a certain end position of that printing area, and autonomously moves and prints according to the preset printing trajectory of that printing area; Step a5: Support reciprocating or spiral printing for different passes to shorten the travel path of the portable printer / copier and improve printing efficiency.

10. A motion planning and control method for a portable printer / copier device with autonomous movement and multi-machine collaboration functions as described in claim 1 or 5, characterized in that, The steps for autonomous stitching and scanning are as follows: Step b1: The portable printer / copier uses the set sensor data to perform autonomous positioning, and obtains the real-time position, angle, angular velocity and / or velocity of the contact image sensor in the scanned image coordinate system; Step b2: In the first scan, based on the positioning result of step b1 and through the autonomous moving device set in step d, control the portable printer / copier to move and scan the image along the boundary direction of the scanned image or any fixed direction; Step b3: In non-first scans, based on the positioning results of step b1 and through the autonomous moving device set in step d, the portable printer / copier is controlled to move and scan the image in a way that is stitched with the previously scanned image, so as to both scan the new area and maintain an overlap with the already scanned area, thereby meeting the requirements for stitching adjacent scanned images. Step b4: Support reciprocating or spiral scanning for different passes, shortening the travel path of portable printers and copiers and improving scanning efficiency.

11. A motion planning and control method for a portable printer / copier device with autonomous movement and multi-machine collaboration functions as described in claim 1 or 5, characterized in that, The steps for multi-machine collaborative autonomous mobile printing are as follows: Step c1: Team up the multiple portable printers and copiers involved in the printing process; Step c2: Create a multi-machine collaborative autonomous mobile print job, and set the data to be printed and the print range on the printing media; Step c3: Distribute the print data and range information to each portable printer / copier; Step c4: Each portable printer / copier plans a different printing path, and together they cover the entire printing area; Step c5: During the printing process, each portable printer / copier performs autonomous positioning to obtain real-time positioning information in the same printing media coordinate system; Step c6: During the printing process, multiple portable printers and copiers communicate in real time, share real-time positioning and / or printed area information, and control the portable printers and copiers to move and print through the autonomous moving device set in step d, ensuring that the printed areas of different passes are seamlessly joined, with no or minimal overlap, and that different printers and copiers do not collide.

12. The motion planning and control method according to claim 11, characterized in that: In multi-machine collaborative autonomous mobile printing tasks, different portable printers and copiers print layers of different colors to meet the color requirements of the printed content.

13. An autonomous movement method for a portable printer / copier device with autonomous movement and multi-machine collaboration functions as described in claim 1, characterized in that, The steps are as follows: Step d1: The portable printer / copier autonomously plans its movement trajectory, including the position, angle, speed and / or angular velocity of the contact image sensor in the printing or scanning coordinate system, which is a 2D coordinate system established based on the printing medium or scanned image; Step d2: Obtain the real-time position, angle, velocity and / or angular velocity information of the contact image sensor in the printing or scanning coordinate system based on the autonomous positioning results; Step d3: The tracking error is obtained by subtracting the target state of the contact image sensor in the planned trajectory set in step d1 from the real-time positioning state of the contact image sensor obtained in step d2. Step d4: Based on the tracking error obtained in step d3 and the kinematics of the autonomous mobile device, calculate and output the control quantities of different actuators in the autonomous mobile device to enable the portable printer / copier to generate a three-degree-of-freedom composite motion and reduce the tracking error; Step d5: For different time steps, iteratively execute steps d2-d4 until the planned trajectory set in step d1 is completed.

14. The autonomous mobility method according to claim 13, characterized in that: In step d4, the method for calculating the control quantities of different actuators in the autonomous mobile device based on the tracking error is the PID algorithm.

15. The autonomous mobility method according to claim 13, characterized in that: In step d5 of the autonomous mobile scanning task, an image is acquired by a contact image sensor to detect whether the portable printer / copier has reached the boundary of the scanning medium in order to determine whether the planned trajectory has been completed.

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