Recharging control method and system for mobile robot

Abstract

The present application relates to a recharging control method and system for a mobile robot. The method comprises the following steps: when a mobile robot needs recharging, determining whether the mobile robot has previously made an active departure from a charging station; if the mobile robot has previously made an active departure from the charging station, controlling the mobile robot to move from the current position to a first preset position, and to acquire a recharging signal at the first preset position; and if the mobile robot has previously made a passive departure from the charging station, controlling the mobile robot to directly acquire a recharging signal at the current position. In this way, the cases of an active departure and a passive departure of a mobile robot from a charging station are determined, and then different charging strategies are formulated on the basis of different ways of departure from the charging station, so that it is ensured that the mobile robot can accurately execute a recharging operation, thereby avoiding unnecessary path planning and waste of time, and thus improving the recharging efficiency.

Description

Method and system for return charging control of mobile robot TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, in particular to a return charging control method and system for a mobile robot. BACKGROUND

[0002] When the mobile robot is short of power or needs to return to the charging station for other reasons, the mobile robot can autonomously move to the charging station and perform operations such as connection of the charging node, monitoring of the charging process, and automatic disconnection after the charging is completed.

[0003] In the prior art, the mobile robot moves to a preset or previously memorized position, then acquires a characteristic signal of the charging station at the position, locates the charging station according to the characteristic signal, and finally moves to the charging station according to the characteristic signal of the charging station, performs docking, and starts charging. However, during the movement of the mobile robot, different situations may occur, such as being moved by a person or being passively moved by colliding with an obstacle, which will affect the positioning of the mobile robot and thus affect the movement of the mobile robot, resulting in a return charging failure. SUMMARY

[0004] Therefore, it is necessary to provide a return charging control method and system for a mobile robot, which can formulate different return charging strategies according to whether the mobile robot actively or passively leaves the charging station, to ensure that the mobile robot can correctly perform the return charging operation and improve the return charging efficiency.

[0005] In a first aspect, the present application provides a return charging control method for a mobile robot, which comprises:

[0006] When the mobile robot needs to return to the charging station, it is determined whether the mobile robot has actively left the charging station previously.

[0007] If the mobile robot has actively left the charging station previously, the mobile robot is controlled to move from the current position to the first preset position and acquire a return charging signal at the first preset position.

[0008] If the mobile robot has passively left the charging station previously, the mobile robot is controlled to directly acquire a return charging signal at the current position.

[0009] In a second aspect, the present application further provides a return charging control system, which comprises a determination module configured to determine whether the mobile robot has actively left the charging station previously when the mobile robot needs to return to the charging station.

[0010] A movement module is configured to control the mobile robot to move from the current position to the first preset position when the mobile robot has actively left the charging station previously.

[0011] The acquisition module is configured to acquire the back charging signal at the first preset position, and further configured to control the mobile robot to acquire the back charging signal directly at the current position if the mobile robot has been passively leaving the charging station.

[0012] The above introduces a back charging control method and system of a mobile robot, including the following steps: when the mobile robot needs to be back charged, judging whether the mobile robot has been actively leaving the charging station or not; if the mobile robot has been actively leaving the charging station, controlling the mobile robot to move from the current position to the first preset position and acquire the back charging signal at the first preset position; if the mobile robot has been passively leaving the charging station, controlling the mobile robot to acquire the back charging signal directly at the current position. Therefore, by judging the active and passive leaving of the charging station of the mobile robot, and then formulating different back charging strategies according to different ways of leaving the charging station, it is ensured that the mobile robot can correctly perform the back charging operation, unnecessary path planning and time waste are avoided, and the back charging efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] Fig. 1 is a structural schematic diagram of a back charging control system of a mobile robot according to the present application;

[0014] Fig. 2 is a side view structural schematic diagram of a mobile robot according to the present application;

[0015] Fig. 3 is a rear view structural schematic diagram of a mobile robot according to the present application;

[0016] Fig. 4 is a bottom view structural schematic diagram of a mobile robot according to the present application;

[0017] Fig. 5 is a schematic diagram of magnetic field intensity distribution generated by a guide line according to the present application;

[0018] Fig. 6 is a flow schematic diagram of a back charging control method of a mobile robot according to the present application;

[0019] Fig. 7 is a flow schematic diagram of another back charging control method of a mobile robot according to the present application;

[0020] Fig. 8 is a flow schematic diagram of still another back charging control method of a mobile robot according to the present application;

[0021] Fig. 9 is a flow schematic diagram of still another back charging control method of a mobile robot according to the present application;

[0022] Fig. 10 is a flow schematic diagram of still another back charging control method of a mobile robot according to the present application;

[0023] Fig. 11 is a structural block diagram of a back charging control system of a mobile robot according to an embodiment of the present application;

[0024] Fig. 12 is a structural block diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0026] Referring to Fig. 1, Fig. 1 is a structural schematic diagram of a back charging control system of a mobile robot, as shown in Fig. 1, the system includes a mobile robot and a charging station, when the mobile robot needs to be charged, the mobile robot will return to the charging station to be charged.

[0027] Referring to Fig. 2, the mobile robot according to the present application is provided with a visual sensor assembly, an infrared signal receiver and a satellite positioning device (not shown in the figure). The visual sensor assembly is used to detect or perceive the surrounding environment information of the mobile robot, so as to realize obstacle avoidance, positioning and back charging. Specifically, the visual sensor assembly includes at least one visual sensor, (such as the mobile robot shown in Fig. 2 and Fig. 3, the visual sensor assembly includes a first visual sensor, a second visual sensor and a third visual sensor, the second visual sensor is used to detect the environment information in front of the mobile robot, and the first visual sensor and the third visual sensor are used to detect the environment information on the side of the mobile robot), the visual sensor can be a monocular or multi-view camera. When the visual sensor detects the characteristic information of the charging station, the characteristic information can be used as a back charging signal to guide the mobile robot to return to the charging station. The infrared signal receiver is used to receive the infrared signal sent by the charging station, and guide the mobile robot to move towards the charging station or control the mobile robot to avoid the charging station according to the infrared signal. Wherein, the infrared signal receiver is located on the front side of the mobile robot and near the visual sensor assembly, specifically, if the visual sensor is a monocular camera, the infrared signal receiver is arranged near the second visual sensor, if the visual sensor is a multi-view camera, the infrared signal receiver is arranged between two cameras. More specifically, if the visual sensor is a binocular sensor, the binocular sensor is located on the central axis of the mobile robot or is symmetrical about the central axis, and the infrared signal receiver is located between the binocular sensor, which helps to improve the synchronization processing capability of the visual signal and the infrared signal. The satellite positioning device is used to receive satellite signals to guide the mobile robot to move according to the satellite signals, especially when the mobile robot does not receive the characteristic information of the charging station, the infrared signal, and the magnetic field signal (which will be introduced below), the mobile robot is mainly guided to move according to the satellite signals.

[0028] Please refer to Fig. 4, which is a structural schematic diagram of the mobile robot viewed from the bottom. As shown in Fig. 4, the chassis of the mobile robot is further provided with a magnetic induction sensor assembly, specifically including a first magnetic induction sensor and a second magnetic induction sensor. Further, the first magnetic induction sensor and the second magnetic induction sensor can be arranged on the front side of the mobile robot in the walking direction, and the first magnetic induction sensor and the second magnetic induction sensor are symmetrically arranged relative to the central axis of the mobile robot, the distance between the two is 7cm-9cm, and the distance between the first magnetic induction sensor and the second magnetic induction sensor from the ground is equal. So that the first magnetic induction sensor and the second magnetic induction sensor can accurately detect the deviation of the mobile robot relative to the magnetic field signal generating device.

[0029] Please refer to Fig. 1 again, the charging station is provided with an infrared signal emitter, the infrared signal emitter alternately emits a first infrared signal and a second infrared signal, the first infrared signal and the second infrared signal emitted by the infrared signal emitter are received by the infrared signal receiver on the mobile robot to guide the mobile robot to return to the charging station. Among them, the infrared signal emitter can be arranged to alternately emit the first infrared signal and the second infrared signal at different times or frequencies. Specifically, the time for turning on the second infrared signal can be set to 100ms, and the time for turning on the first infrared signal can be set to 200ms; or the first infrared signal is emitted twice, and then the second infrared signal is emitted once, so that the infrared signal receiver can accurately distinguish the second infrared signal from the first infrared signal. It should be pointed out that the difference between the first infrared signal and the second infrared signal is that their radiation distances are different, that is, the farthest distances of the first infrared signal, the visual signal and the second infrared signal radiation decrease in turn, and by setting the gradient of the signal radiation distance, the robot can gradually reduce the search range during the return charging process, and finally realize accurate docking with the charging station, thereby improving the accuracy and efficiency of the return charging. For example, the farthest distance of the first infrared signal radiation can be 7m, the farthest distance of the visual signal radiation can be 3m, and the farthest distance of the second infrared signal radiation can be 2m.

[0030] Specifically as shown in Fig. 1, the coverage area range of various different return charging signals that can guide the mobile robot to return to charge is shown. Among them, the coverage area range of the first infrared signal is area 1, that is, its radiation range covers area 1. The coverage area range of the second infrared signal is area 2, that is, its radiation range covers area 2, and the coverage area of the visual return charging signal is area 3. The mobile robot can detect the first intersection between the area of the visual return charging signal (i.e. the coverage area of the visual return charging signal) and the coverage area of the first infrared signal, and the coverage area of the second infrared signal is in the first intersection.

[0031] That is, normally, if the mobile robot is in the range of area 1 except area 3, the infrared signal receiver of the mobile robot can detect the first infrared signal sent by the charging station; if the mobile robot is in area 3, the visual sensor of the mobile robot can detect the visual charging signal of the charging station, and guide the mobile robot to charge by using the visual charging signal; if the mobile robot is in area 2, the infrared signal receiver of the mobile robot can detect the second infrared signal sent by the charging station, and guide the mobile robot to charge by using the second infrared signal.

[0032] In the embodiment, area 1 can be a sector, petal or ellipse with an angle range of 160-180 degrees and a radius of 7-9 meters, area 2 can be a sector, petal or ellipse with an angle range of 160-180 degrees and a radius of 1-2 meters, and area 3 can be a sector with an angle range of 160-180 degrees and a radius of 2-3 meters.

[0033] Referring back to FIG. 1, the charging station further comprises a base for the mobile robot to stop and a guide line for guiding the mobile robot to charge, the guide line is arranged on the back or front of the base, and the guide line is symmetrical about the central axis of the base. Since the guide line is arranged on the base, a closed guide area (the width L of the guide area is about 18-22 cm) is formed by the arrangement of the guide line, and when the central axis of the mobile robot is approximately coincident with the central axis of the base, the first magnetic induction sensor and the second magnetic induction sensor are located in the closed guide area. Since the guide line is in an energized state, a magnetic field signal can be generated near the base of the charging station, and the magnetic induction sensor assembly of the mobile robot can detect the magnetic field signal of the guide line within a certain range. Further, the processor of the mobile robot can determine the distance and direction of the mobile robot from the charging station according to the polarity and intensity of the magnetic field signal, and then send a control signal to control the mobile robot to adjust the moving direction so that the central axis of the mobile robot is approximately coincident with the central axis of the base.

[0034] Please refer to Fig. 5, which is a schematic diagram of the magnetic field intensity distribution generated by the guide line. Assuming that the first magnetic induction sensor is arranged at the right side of the front side of the mobile robot in the walking direction of the mobile robot, and the second magnetic induction sensor is arranged at the left side of the front side of the mobile robot in the walking direction of the mobile robot, when the intensity of the magnetic field signal detected by the first magnetic induction sensor is weaker than the intensity of the magnetic field signal detected by the second magnetic induction sensor, the mobile robot can be controlled to adjust the position to the left; when the intensity of the magnetic field signal detected by the first magnetic induction sensor is stronger than the intensity of the magnetic field signal detected by the second magnetic induction sensor, the mobile robot can be controlled to adjust the position to the right; when the intensity of the magnetic field signal detected by the first magnetic induction sensor is not much different from the intensity of the magnetic field signal detected by the second magnetic induction sensor (within a preset range), the mobile robot can be controlled to move straight. The mobile robot detects the magnetic field signal in real time and adjusts the walking direction in real time. When the mobile robot adjusts the direction, the mobile robot moves relatively slowly and the rotation amplitude is relatively small, so that the mobile robot can make correction at any time.

[0035] Please refer to Fig. 1 again. The coverage area of the magnetic field signal is area 4, and the area of the area 4 is larger than the closed guide area formed by the guide line, because the magnetic field signal can radiate to both sides of the guide line. The coverage area of the visual back charging signal intersects with the coverage area of the magnetic field signal.

[0036] The front side of the mobile robot is also provided with a charging connector, and the charging station also includes a charging pole, wherein the charging pole is symmetrical about the central axis of the base, and the projection of the end of the charging pole on the base is located in the guide area. When the mobile robot moves along the central axis of the charging station under the guidance of the guide line until the charging connector of the mobile robot touches and docks with the charging pole, the controller of the mobile robot can recognize the charging state of the mobile device and control the mobile robot to stop moving.

[0037] The above is the basic structure of the mobile robot and the charging station, and the back charging control method of the mobile robot is designed based on the basic structure. Details are described below.

[0038] Please refer to Fig. 6, which is a flowchart of a back charging control method of a mobile robot according to an embodiment of the present application. As shown in Fig. 6, the back charging control method of the present embodiment includes the following steps:

[0039] Step S1: When the mobile robot needs to be back charged, it is judged whether the mobile robot has actively left the charging station before.

[0040] The conditions under which the mobile robot needs to be back charged include the following conditions:

[0041] First: The mobile robot judges that the power of the mobile robot is insufficient, and needs to be charged;

[0042] Second: The mobile robot receives a back charging instruction;

[0043] Thirdly, a key component inside the mobile robot fails, such as a wheel or a positioning sensor, which affects the mobile robot to continue working;

[0044] Fourthly, the mobile robot completes a work task;

[0045] Fifthly, the mobile robot needs to be cleaned by a cleaning device on the charging station, such as cleaning a vision sensor on the mobile robot, or cleaning a moving wheel of the mobile robot, or cleaning a mowing assembly on a mowing robot, etc.

[0046] Sixthly, a storage box on the mobile robot is full, such as the grass in a grass collecting frame of a mowing robot is full.

[0047] Active departure from the charging station refers to that the mobile robot actively departs from the charging station for performing cleaning, patrolling, etc. Passive departure from the charging station refers to that the mobile robot accidentally departs from the charging station due to external factors (such as human movement, collision, etc.).

[0048] Specifically, it can be determined whether the mobile robot exists at least one of the following situations: the angle value of the IMU sensor of the mobile robot is less than a preset angle value, and / or the off-ground sensor is not started, and there is a down point, a received work instruction, and an unfinished task. If it exists, it is determined that the mobile robot is actively departing from the charging station, and if it does not exist, it is determined that the mobile robot is passively departing from the charging station.

[0049] If the angle change of the IMU sensor is too large, greater than or equal to the preset angle value, or the off-ground sensor is started, it means that the mobile robot may be moved, resulting in a large tilt angle and off-ground.

[0050] When the mobile robot actively down stakes, a down point will be recorded on the path of down staking, which is usually near the charging station. If the down point does not exist, it means that the mobile robot is not actively down staking, for example, it may be passively down staked due to being moved by a person from the charging station.

[0051] If the mobile robot does not receive a work instruction and suddenly stops charging and down staking, it can be determined that the mobile robot is passively departing from the charging station.

[0052] If there is no work task, i.e., all work tasks have been completed, and the mobile robot departs from the charging station, it can be determined that the mobile robot is passively departing from the charging station.

[0053] If there is a communication connection between the charging station and the mobile robot, the communication log or signal record can be analyzed. If abnormal signals or communication interruption is found, it can be determined that the mobile robot is passively departing from the charging station.

[0054] Therefore, whether the mobile robot is passively or actively leaving the charging station can be determined by the different situations described above. By comprehensively considering different situations, the accuracy of determining the manner in which the mobile robot leaves the charging station can be improved.

[0055] Step S2: If the mobile robot has previously actively left the charging station, the mobile robot is controlled to move from the current position to a first preset position, and a charging signal is acquired at the first preset position.

[0056] The first preset position generally refers to a position at which the mobile robot can successfully charge, and can include any one of the following positions:

[0057] 1. A position at a distance of about 0-3 meters in front of the charging station and near the central axis of the charging station;

[0058] 2. A position point in the area covered by the visual charging signal;

[0059] 3. A position point in the area covered by the first infrared signal;

[0060] 4. A position point in the magnetic field signal area generated by the guide line;

[0061] 5. A position point in the intersection of the area covered by the visual charging signal and the area covered by the first infrared signal.

[0062] The first preset position can be a fixed position point set in advance, or a position point dynamically calculated based on the charging station position and the current position of the mobile robot. By flexibly setting the first preset position, the mobile robot can more efficiently perform a rotating action and acquire charging information during the process of returning to the charging station.

[0063] The first position described above is a position point further narrowed to the central axis of the charging station and at a preset distance from the charging station. By narrowing the range of the first preset position, the accuracy and efficiency of detecting charging information when the mobile robot performs a rotating action are improved, and the charging process is further optimized.

[0064] If the mobile robot actively leaves the charging station, it means that it leaves the charging station to perform a task or the like, and there is a normal movement path, i.e., the positioning of the mobile robot is relatively accurate. Therefore, the mobile robot can autonomously navigate to the first preset position according to a path planning algorithm.

[0065] The charging signal can include at least one of a first charging signal, a second charging signal, and a third charging signal.

[0066] The first return charging signal can be a visual return charging signal. The visual return charging signal can include feature information of the charging station or feature information of a feature marker arranged on the charging station. As described above, the visual return charging signal can be acquired by a visual sensor of the mobile robot. Specifically, the image captured by the visual sensor can be analyzed by color recognition, shape matching, edge detection, etc. to extract feature information related to the charging station. The extracted feature information is compared with preset feature information of the charging station in terms of color, shape, size, etc. If the comparison is successful, it means that the visual sensor has acquired the feature information of the charging station. If the comparison is not successful, it means that the visual sensor has not acquired the feature information of the charging station. Meanwhile, the accuracy of the acquisition result of the visual sensor can be verified by actual verification. For example, the charging station can be manually checked to determine whether it actually exists, or cross verification can be performed by other sensors.

[0067] The second return charging signal includes an infrared signal. The infrared signal is a signal emitted by the charging station, which can include a first infrared signal and a second infrared signal. The mobile robot can receive the second return charging signal through an infrared signal receiver.

[0068] The third return charging signal is a magnetic field signal generated when the guide wire of the charging station is conductive. The mobile robot can acquire the third return charging signal through a first magnetic induction sensor and a second magnetic induction sensor.

[0069] In an embodiment, the coverage area of the visual return charging signal has a first intersection with the coverage area of the first infrared signal, the second infrared signal is in the first intersection, and the coverage area of the visual return charging signal has a second intersection with the coverage area of the third return charging signal.

[0070] It can be understood that the first return charging signal can also be an infrared signal, and the second return charging signal can be a visual return charging signal. In this step, the return charging signal acquired at the first preset position can be any one of the first return charging signal, the second return charging signal, and the third return charging signal. Specifically, at the first preset position, it can be first determined whether the infrared signal can be detected. If the infrared signal cannot be detected, it can be further determined whether the visual return charging signal can be acquired. If the visual return charging signal can be acquired, it means that the return charging signal is acquired, and the mobile robot is guided to return to charging based on the visual return charging signal. Alternatively, at the first preset position, it can be first determined whether the visual return charging signal can be detected. If the visual return charging signal cannot be detected, it can be further determined whether the infrared signal can be acquired. If the infrared signal can be acquired, it also means that the return charging signal is acquired, and the mobile robot is guided to return to charging based on the infrared signal.

[0071] Step S3: If the mobile robot has been passively leaving the charging station, the mobile robot is controlled to directly acquire the return charging signal at the current position.

[0072] If the mobile robot is passively leaving the charging station, it indicates that the current positioning accuracy of the mobile robot is low, and the mobile robot can attempt to obtain the return charging signal at the current position. If the return charging signal can be obtained at the current position, the mobile robot is controlled to move to the charging station according to the obtained return charging signal. If the return charging signal cannot be obtained at the current position, the mobile robot is directly stopped and an error is reported to avoid the mobile robot moving to a forbidden area or an area that cannot be entered, thereby improving the safety of the mobile robot in operation. For example, if the mobile robot is passively leaving the charging station and is moved to another area that is not in communication with the charging station, it is directly determined that the mobile robot cannot return to the charging station, and the mobile robot can directly report an error. In this way, the mobile robot can avoid performing invalid operations in the case of being unable to return to the charging station, and timely notify the user to intervene. After the error is reported and the mobile robot is stopped, the mobile robot is in a dormant state, and a message or / and a voice prompt is sent to the user to indicate that the return charging fails.

[0073] The embodiment executes different return charging strategies based on whether the mobile robot actively leaves the charging station. When the mobile robot actively leaves the charging station, the mobile robot is controlled to move to the first preset position. When the mobile robot is passively leaving the charging station, the mobile robot is controlled to rotate at the current position to ensure that the return charging signal can be received. In this way, the problem of how the mobile robot returns to the charging station in different leaving states is solved. For the case of actively leaving the charging station, it is ensured that the mobile robot can accurately return to the charging position. For the case of passively leaving the charging station, the position is adjusted by rotating to receive the return charging signal. Through the above control strategy, the return charging efficiency and accuracy of the mobile robot can be improved, the energy waste caused by the failure of return charging can be reduced, the autonomous operation capability of the mobile robot can be improved, and it is ensured that the mobile robot can successfully return to the charging station in various situations, thereby prolonging the working time of the mobile robot and improving the operation efficiency.

[0074] Referring to FIG. 7, the step S2 of obtaining the return charging signal at the first preset position or the step S3 of controlling the mobile robot to directly obtain the return charging signal at the current position further includes the following steps.

[0075] Step S11: determining whether the mobile robot meets the rotation condition.

[0076] Specifically, it can be determined whether at least one of the first return charging signal, the second return charging signal, and the third return charging signal is obtained. If at least one of the above signals is not obtained, it is determined that the preset rotation condition is met, and the process jumps to step S12. Otherwise, it is determined that the preset rotation condition is not met, and the process jumps to step S13.

[0077] By judging the first return charging signal, the second return charging signal, and the third return charging signal, it can be determined whether the mobile robot rotates, which can avoid the mobile robot performing useless rotating actions, thereby improving the overall return charging efficiency.

[0078] Step S12: If the mobile robot meets the rotation condition, control the mobile robot to rotate at the first preset position or at the current position to obtain the return charging signal.

[0079] When the mobile robot reaches the first preset position or at the current position, the moving direction of the mobile robot may not be towards the charging station, and the angle of the signals received by various sensors of the mobile robot is limited, for example, the angle of the field of view of the visual sensor is limited, and further, the angle of the second return charging signal and the third return charging signal emitted by the charging station is also limited. If the moving direction of the mobile robot is not towards the charging station, the mobile robot may not be able to obtain an effective return charging signal, so at this time the mobile robot needs to be controlled to rotate to try to obtain the return charging signal. As in the acquisition of the first return charging signal, during the rotation of the mobile robot, the collected environmental information needs to be analyzed in real time, and the environmental information represents the characteristic information of the charging station.

[0080] In this step, specifically, when the mobile robot meets the rotation condition, if the mobile robot is actively leaving the charging station, it is first moved to the first preset position and then rotated; if the mobile robot is passively leaving the charging station, it is directly rotated at the current position. Further, if the mobile robot still does not obtain the return charging signal after being controlled to rotate at the current position, the mobile robot is controlled to move to a third preset position and rotate to obtain the return charging signal. The third preset position can be the position of the charging station recorded internally before or the position of the return charging signal recorded internally, and further moving to the third preset position to rotate can increase the probability of obtaining the return charging signal.

[0081] Further, if the mobile robot still does not obtain the return charging signal after being controlled to move to the third preset position and rotate, the mobile robot is controlled to perform the rotation action again at the third preset position, wherein the center of rotation of the rotation is located outside the body of the mobile robot. That is, the radius of rotation is expanded to obtain the return charging signal in a larger range and increase the probability of obtaining the return charging signal.

[0082] Step S13: If the mobile robot does not meet the rotation condition, directly obtain the return charging signal at the first preset position or at the current position.

[0083] If the mobile robot does not meet the rotation condition, that is, the mobile robot has obtained at least one of the first return charging signal, the second return charging signal, and the third return charging signal, the return charging signal can be directly obtained, and the mobile robot is guided to return to charge according to the return charging signal. Specifically, if the mobile robot is actively leaving the charging station, the return charging signal is directly obtained at the first preset position, and then the mobile robot is guided to return to charge according to the return charging signal; if the mobile robot is passively leaving the charging station, the return charging signal is directly obtained at the current position, and then the mobile robot is guided to return to charge according to the return charging signal.

[0084] The above describes judging whether to obtain at least one of the first return charging signal, the second return charging signal and the third return charging signal to judge whether the rotation condition is met. In another embodiment, whether the mobile robot meets the rotation condition can also be judged by judging whether the mobile robot is rotationally blocked. Specifically, if the mobile robot is rotationally blocked (i.e., cannot perform a rotation action due to the presence of an obstacle near the mobile robot), it means that the mobile robot does not meet the rotation condition, and the mobile robot needs to be controlled to move away from the obstacle until the mobile robot can rotate, and then the mobile robot is controlled to rotate to obtain the return charging signal.

[0085] In this embodiment, by first judging whether the rotation condition is met, and then controlling the mobile robot to rotate when the rotation condition is met, the mobile robot is prevented from blindly rotating and performing useless rotation actions, thereby improving the overall return charging efficiency.

[0086] In an embodiment, after the mobile robot is controlled to rotate, it can be further judged whether the mobile robot obtains the return charging signal. If the return charging signal is obtained, the mobile robot is guided to return charge according to the return charging signal. The mobile robot obtains the return charging signal through rotation, and then is guided to return charge according to the return charging signal, so that the mobile robot can successfully return charge.

[0087] In an embodiment, if the mobile robot has actively left the charging station before, and the return charging signal is not obtained at the first preset position, the mobile robot is controlled to move to a second preset position, and the mobile robot is controlled to rotate at the second preset position to obtain the return charging signal.

[0088] Specifically, the mobile robot is controlled to rotate at the second preset position to judge whether the return charging signal is obtained. If the return charging signal is obtained, the mobile robot is guided to return charge according to the return charging signal. Since the mobile robot may encounter various environmental changes such as obstacles and changes in illumination during movement, affecting the positioning of the mobile robot, resulting in accumulated positioning errors, the "first preset position" to which the mobile robot moves according to the preset rules may not be the actual first preset position. At this time, the mobile robot may not be able to detect the return charging signal, and thus cannot achieve return charging. Therefore, in this embodiment, when the return charging signal cannot be obtained at the first preset position, the mobile robot is controlled to move to the second preset position to attempt to obtain the return charging signal at another position, thereby increasing the probability of obtaining the return charging signal and thus increasing the success rate of return charging.

[0089] However, before the mobile robot moves to the second preset position, the number of movements of the mobile robot can be further judged. For details, refer to FIG. 8, which is a flowchart of a return charging control method of a mobile robot according to an embodiment of the present application. As shown in FIG. 8, the method can specifically include the following steps:

[0090] Step S21: judging whether the number of times of moving the mobile robot is less than a preset number of times.

[0091] Step S22: if the number of times of moving is less than the preset number of times, controlling the mobile robot to move to a second preset position.

[0092] Step S23: if the number of times of moving is greater than or equal to the preset number of times, controlling the mobile robot to stop moving and sending a message prompt or / and a voice prompt.

[0093] In an embodiment, the preset number of times is not greater than 3. Since the reasons for the mobile robot failing to acquire the charging signal are complex, it cannot be determined whether the problem is with the sensor, such as a vision sensor, detected by the mobile robot itself or the surrounding environment is disturbed. If the surrounding environment is disturbed, the disturbance can be avoided by moving, and if the problem is with the sensor of the mobile robot itself, the charging signal cannot be acquired by changing the position. Therefore, after moving multiple times and still failing to detect the charging signal, the mobile robot stops moving and is in a dormant state. The mobile robot sends a message prompt or / and a voice prompt to the user to indicate that the charging fails. In this embodiment, by setting a preset number of times, the system can determine whether to continue moving the mobile robot or stop moving according to the number of times of moving, thereby solving the problem of how to effectively control the mobile robot to stop moving after completing the task, avoiding waste of resources and reduction of efficiency, effectively saving energy and improving work efficiency.

[0094] The second preset position is set in the same way as the first preset position, i.e., at a position where the mobile robot can be successfully charged. Specifically, the first preset position and the second preset position can satisfy the following relationship: AB = BC and AB perpendicular to BC.

[0095] Wherein, A is the position coordinate of the center of the wheel shaft of the mobile robot when it is parked on the charging station, B is the coordinate of the first preset position, and C is the coordinate of the second preset position.

[0096] That is, the first preset position and the second preset position are equidistant from the charging station, and the second preset position is one of the two positions on the two sides of the first preset position relative to the charging station, and the two lines of the first preset position and the second preset position are perpendicular to the line connecting the first preset position and the charging station. The coverage area of the collection return charging signal, under normal circumstances, the first preset position and the second preset position can both obtain the return charging signal through the sensor, for example, the visual return charging signal (i.e. the first return charging signal) can be obtained through the visual sensor. By defining the geometric relationship (isosceles right triangle) between the second preset position and the first preset position (i.e. the position of the mobile robot wheel shaft center on the charging station), it is ensured that the mobile robot can face the charging station at a suitable angle and distance when moving to the second preset position, solving the problem of how to accurately control the mobile robot to reach a preparatory position that is conducive to return charging, improving the accuracy and success rate of the mobile robot return charging, and reducing the failure of return charging due to improper position.

[0097] When there are two second preset positions, the two second preset positions are symmetrically arranged on the two sides of the first preset position. If the return charging signal is not obtained at one of the second preset positions (such as position C1 shown in FIG. 1), the mobile robot is controlled to move from the second preset position to the other second preset position (such as position C2 shown in FIG. 1), and the mobile robot is controlled to rotate at position C2 to obtain the return charging signal, wherein position C2 and position C1 are symmetrically arranged on the two sides of the first preset position. That is, if the return charging signal is not obtained on one side of the first preset position, the mobile robot is controlled to move to the other side of the first preset position to continue to obtain the return charging signal. In this way, the probability of obtaining the return charging signal is improved by continuing to attempt to obtain the return charging signal at other preset positions. Position C2 and position C1 are symmetrically arranged relative to the first preset position, which can ensure that the field of view of the mobile robot at the two positions is the same, and the difficulty of obtaining the return charging signal is equivalent.

[0098] In an embodiment, if the mobile robot has previously left the charging station passively and the return charging signal is not obtained, the mobile robot is controlled to stop moving and send a message prompt and / or a voice prompt. After sending the message prompt and / or the voice prompt, the mobile robot is in a dormant state to reduce the power consumption of the mobile robot.

[0099] In an embodiment, the specific method of controlling the mobile robot to move to the first preset position in step S2 can be to plan a navigation path for the mobile robot, which can specifically include the following:

[0100] The first kind: obtain the coordinates of the current position of the mobile robot and the coordinates of the first preset position, plan a shortest path from the current position to the first preset position, and judge whether there is an obstacle on the shortest path. If there is an obstacle, a planning path that avoids the obstacle is generated;

[0101] Secondly, based on historical maps, a satellite signal map of the working area is obtained, and a region where the satellite signal strength is greater than a preset value is obtained, and a navigation path is planned to the region where the satellite signal strength is greater than the preset value.

[0102] Thirdly, a path avoiding sunlight directly irradiating the visual sensor is planned. Specifically, if the irradiation direction of the sunlight is perpendicular to the optical window of the sensor, it is considered that the sunlight directly irradiates the visual sensor, and at this time, the planned path is required to form an angle greater than 30 degrees with the direction of sunlight irradiation to avoid the sunlight from interfering with the visual sensor.

[0103] Different navigation paths can be planned according to different situations. For example, if it is noon with sufficient sunlight, the navigation path can be planned in the first or second case to avoid the influence of sunlight, if the working area is in a remote place and the satellite signal strength is weak, the navigation path can be planned in the first or third case to avoid the influence of satellite signals, and so on. Thus, the planned navigation path can be more in line with the current moving conditions.

[0104] After the navigation path is planned, the mobile robot is moved to the first preset position according to the navigation path. Specifically, the environment information obtained based on the satellite positioning device and / or the visual sensor is used for positioning, and the mobile robot is controlled to move along the navigation path to the first preset position according to the positioning information. In the area where the satellite signal quality is good, the satellite positioning device can be used for positioning only, in the area where the satellite signal quality is not good, the visual sensor or the visual sensor and the satellite positioning device can be used for positioning together, or the visual sensor can be used for positioning only. The robot is controlled to move along the navigation path through the positioning information of the robot. Therefore, the movement of the mobile robot can be positioned in real time through the positioning device, and the mobile robot moves in combination with the real-time positioning information and the navigation path, which can avoid temporary obstacles and the like, thereby ensuring that the mobile robot can move smoothly.

[0105] In an embodiment, since the recharging signal includes the first recharging signal, the second recharging signal and the third recharging signal, and the second recharging signal includes the first infrared signal and the second infrared signal, in the above-mentioned scheme, different recharging strategies can be further performed according to the different recharging signals obtained when the recharging signal is obtained. For details, please refer to FIG. 9, which is a flow diagram of another recharging control method of a mobile robot provided by the embodiment of the present application. As shown in FIG. 9, the method can specifically include the following steps:

[0106] Step S31: If the first infrared signal is obtained, the mobile robot is guided to move by using the first infrared signal, and it is judged whether the second infrared signal, the first recharging signal and / or the third recharging signal is obtained.

[0107] Since the first infrared signal is emitted from a long distance, the mobile robot may not be able to obtain the second infrared signal, the first return charging signal and / or the third return charging signal at the position where the first infrared signal is obtained, and thus the mobile robot needs to be guided according to the first infrared signal and it is determined whether the second infrared signal, the first return charging signal and / or the third return charging signal is obtained during the movement.

[0108] Step S32: If the second infrared signal, the first return charging signal and / or the third return charging signal is obtained, the mobile robot is guided to continue return charging according to the second infrared signal, the first return charging signal and / or the third return charging signal.

[0109] In this step, one of the following schemes can be specifically included:

[0110] The first scheme: a return charging path is planned through the first return charging signal, and the mobile robot is guided to return charge according to the return charging path.

[0111] Specifically, the mobile robot first pre-processes the image data of the obtained visual return charging signal (i.e., the first return charging signal), and then uses image processing techniques and computer vision algorithms (such as edge detection, color segmentation, shape matching, etc.) to identify the boundaries of the working area, obstacles (such as trees, rocks, etc.) and the position of the charging base station. By analyzing the feature information in the image, the relative positional relationship between the mobile robot and the charging station is determined. Further, based on the results of image recognition and target detection, a path planning algorithm (such as A* algorithm, genetic algorithm, etc.) is used to generate an optimal path for the mobile robot from the current position to the charging base station. Considering the shape, size of the working area and the distribution of obstacles, the path planning algorithm will try to shorten the path length, reduce the travel time and avoid collision with obstacles.

[0112] During the return charging process, the real-time positioning of the mobile robot can be further realized by combining various sensors such as inertial measurement unit (IMU) and global navigation satellite system (GNSS).

[0113] In this scheme, the return charging path can be planned by obtaining a visual return charging signal, so as to provide navigation guidance for the mobile robot in combination with the path planning result, to ensure that it can accurately travel to the charging base station according to the planned path, without the need to obtain the visual return charging signal in real time, reducing the computing power of the mobile robot, thereby saving the cost of computing power.

[0114] The second scheme: during the control of the return charging of the mobile robot, the first return charging signal is obtained in real time, and the mobile robot is guided to return charge according to the first return charging signal.

[0115] In the scheme, the first return charging signal is acquired in real time during the process of controlling the mobile robot to return to charge, and the moving direction of the mobile robot is adjusted in real time according to the first return charging signal, so as to avoid the mobile robot from colliding with obstacles, especially temporary obstacles, and to ensure the safety of the mobile robot.

[0116] The third scheme: based on the first return charging signal, the mobile robot is controlled to move until the second infrared signal or the third return charging signal is detected, and then the mobile robot is guided to return to charge according to the second infrared signal or the third return charging signal.

[0117] In the scheme, the visual return charging signal (i.e. the first return charging signal), the second infrared signal and the magnetic field signal (i.e. the third return charging signal) are combined to control the mobile robot to return to charge. The second infrared signal is a signal emitted by the charging station, and the radiation distance is about 2m, which is very close to the charging station. The magnetic field signal is emitted by the guide wire of the charging station, and the distance from the charging station is also very close. In the case of close distance, the visual sensor may only obtain part of the feature information of the charging station due to the field angle, and cannot fully reflect the characteristics of the charging station. In this case, the second infrared signal or the magnetic field signal is combined to detect and locate the charging station, which can improve the positioning accuracy and the success rate of return charging.

[0118] By using multiple types of return charging signals (including the second infrared signal, the visual return charging signal and the magnetic field signal) to guide the mobile robot to return to charge, the problem of how to effectively guide the mobile robot to return to charge under different conditions (such as insufficient light and blocked view) is solved, the adaptability and robustness of the mobile robot to return to charge are improved, and it is ensured that the mobile robot can successfully return to charge in various environments.

[0119] The effects of the above several schemes of guiding the mobile robot to return to charge according to different return charging signals are different, and in actual application, a suitable return charging scheme can be selected according to actual conditions, and the present application is not limited.

[0120] As described above, the mobile robot comprises two symmetrically arranged magnetic induction sensors (including a first magnetic induction sensor and a second magnetic induction sensor) for acquiring the magnetic field signal. In the above-mentioned scheme of jointly controlling the mobile robot to return to charge according to the visual return-to-charge signal and the magnetic field signal, it can be further specified as follows: according to the first return-to-charge signal, the mobile robot is controlled to move until the two magnetic induction sensors of the mobile robot both detect the magnetic field signal, and then the mobile robot is guided to return to charge according to the magnetic field signal. In this way, when the mobile robot is far away from the charging station, the mobile robot can be guided to move towards the charging station by the first return-to-charge signal, and when the mobile robot is close to the charging station, the two symmetrically arranged magnetic induction sensors can be used to detect the magnetic field signal emitted by the charging station. When both the two sensors detect the magnetic field signal, it indicates that the mobile robot has arrived near the charging station, and then the mobile robot is guided to return to charge according to the magnetic field signal, thereby solving the problem of how to more accurately determine whether the mobile robot has arrived at the accurate position of the charging station, reducing the return-to-charge failure caused by position deviation, and further improving the accuracy and stability of the mobile robot to return to charge.

[0121] Specifically, when the mobile robot is guided to return to charge according to the magnetic field signal, the pose of the mobile robot can be adjusted so that the difference between the signal strengths of the two magnetic induction sensors is within a preset range. That is, if the absolute value of the difference between the third return-to-charge signal detected by the first magnetic induction sensor and the third return-to-charge signal detected by the second magnetic induction sensor is greater than a preset value, the mobile robot is controlled to adjust the moving direction; if the absolute value of the difference between the third return-to-charge signal detected by the first magnetic induction sensor and the third return-to-charge signal detected by the second magnetic induction sensor is less than or equal to the preset value, the mobile robot does not need to be controlled to adjust the moving direction. Because the two magnetic induction sensors are symmetrically arranged with respect to the central axis of the mobile robot, when the strengths of the magnetic field signals detected by the two magnetic induction sensors are equal, the mobile robot and the charging station can be aligned. By detecting the magnetic field signal by the magnetic induction sensor and adjusting the pose of the mobile robot, it is ensured that the difference between the signal strengths of the two magnetic induction sensors is within a preset range, thereby solving the problem that the mobile robot may not be able to successfully dock with the charging station due to inaccurate pose during the magnetic field guided return-to-charge process. By adjusting the pose, it is ensured that the mobile robot can accurately align with the charging station, thereby improving the return-to-charge success rate.

[0122] Step S33: If the second infrared signal, the first return-to-charge signal and / or the third return-to-charge signal are not acquired, the robot is guided to return to charge according to the first infrared signal.

[0123] In this embodiment, the second charging signal is further divided into a first infrared signal and a second infrared signal, wherein the coverage area of the second infrared signal is located in the intersection of the coverage areas of the first infrared signal and the visual charging signal. If the mobile robot obtains the first infrared signal, the mobile robot is guided to move into the coverage area of the visual charging signal, the coverage area of the second infrared signal and / or the coverage area of the third charging signal according to the first infrared signal, so as to obtain the visual charging signal, the second infrared signal and / or the third charging signal. The mobile robot is further guided to charge according to the visual charging signal, the second infrared signal and / or the third charging signal. This embodiment solves the positioning error problem caused by signal cross interference when the mobile robot approaches the charging position. By refining the coverage range of the infrared signal and combining the visual charging signal and the second infrared signal and the third charging signal for accurate positioning, the positioning accuracy and stability of the mobile robot during the charging process are further improved, and the smooth progress of the charging process is ensured.

[0124] In an embodiment, as described above and shown in FIGS. 2 and 3, the mobile robot comprises a first visual sensor, a second visual sensor and a third visual sensor, wherein the first visual sensor and the third visual sensor are arranged on the two sides, and the second visual sensor is arranged in front of the mobile robot, and the first visual sensor, the second visual sensor and the third visual sensor are used to obtain the first charging signal. If only the second infrared signal and the third charging signal are detected in step S32, the mobile robot is controlled to rotate, and the first charging signal is obtained by using the second visual sensor and the third sensor. Since the second infrared signal and the third charging signal are obtained, it indicates that the mobile robot has been located near the charging station, and under normal circumstances, the visual sensor can obtain the first charging signal (i.e. the charging station information of the charging station). If the first charging signal cannot be obtained at this time, it indicates that the second visual sensor facing the charging station is at least partially damaged or blocked, or the optical window thereof is contaminated, and at this time, the mobile robot needs to be controlled to rotate, and the first charging signal is obtained by using other visual sensors. For example, the second visual sensor is a binocular camera, and one of the binocular cameras cannot detect the first charging signal, and the mobile robot is rotated to face the other binocular camera to the charging station direction to obtain the first charging signal. For another example, if the second visual sensor cannot obtain the first charging signal, the second sensor and the third sensor on the side are turned to the charging station direction to obtain the first charging signal. The success rate of obtaining the first charging signal can be improved. If all the visual sensors cannot obtain the first charging signal, the machine is stopped and an error is reported.

[0125] It is worth noting that in the above-mentioned various schemes for guiding the mobile robot to return to charging according to the first return-to-charge signal, no matter which scheme is adopted, the offset of the mobile robot can be obtained according to the first return-to-charge signal, and the mobile robot is guided to return to charging according to the offset. The offset includes an offset distance and an offset angle. By using the first return-to-charge signal (such as a visual return-to-charge signal) to obtain the offset (including the offset distance and the offset angle) between the mobile robot and the charging station, and then guiding the mobile robot to return to charging according to the offset, the problem that the mobile robot cannot accurately dock with the charging station due to position or direction deviation during visual guidance return-to-charge is solved. By accurately calculating the offset and adjusting the position and direction of the mobile robot, more accurate return-to-charge docking can be achieved, and the return-to-charge success rate is improved.

[0126] A further scheme for guiding the mobile robot to return to charging according to the offset can be as shown in FIG. 10, including the following steps:

[0127] Step S41: Determine the central axis of the charging station.

[0128] Step S42: Determine the offset distance according to the current position of the mobile robot and the central axis, and determine the offset angle according to the current direction of the mobile robot and the vertical direction of the entrance of the charging station.

[0129] Step S43: Control the mobile robot to move to the central axis of the charging station according to the offset distance and the offset angle, and align along the central axis.

[0130] Specifically, when the charging connector of the mobile robot is docked with the charging pad of the charging station, the mobile robot is controlled to continue moving for a preset time and / or a preset distance and then stop moving. Because the charging connector and the charging pad are docked, the mobile robot can recognize that it enters the charging state with the charging station, but the charging connector is not in a stable electrical connection state, so the mobile robot needs to be controlled to continue moving to make the charging connector and the charging pad in close contact, increase the stability of the connection between the two, and thus improve the stability of the charging.

[0131] The embodiment first determines the offset distance and the offset angle between the mobile robot and the charging station, and then guides the robot to move to the central axis of the charging station according to the offset angle and the offset distance, and align along the central axis, so that the mobile robot adjusts the alignment posture on the central axis. This scheme further refines the process of obtaining the offset and guiding the return to charging, including determining the central axis of the charging station, calculating the offset distance and the offset angle, and controlling the mobile robot to move to the central axis of the charging station and align according to the offset distance and the offset angle. The problem that the mobile robot may fail to return to charging due to inaccurate judgment of the offset during the return-to-charge process is solved. Through accurate offset calculation and return-to-charge guidance, the mobile robot can accurately dock with the charging station, and the return-to-charge efficiency and success rate are improved.

[0132] It is worth noting that in the above description of the present application, all the schemes for controlling the mobile robot to rotate can be specifically: controlling the mobile robot to rotate according to a preset direction and angle, and stopping rotating if the first return charging information meeting the condition is obtained during the rotation. For example, the mobile robot can be controlled to rotate in a clockwise or counterclockwise direction, and if complete feature information of the charging station is obtained during the rotation, it can be considered that the first return charging signal meeting the condition is obtained, and the rotation is stopped. This scheme describes that in the process of controlling the mobile robot to rotate, the mobile robot rotates according to a preset direction and angle, and continuously detects whether the first return charging information meeting the condition is obtained during the rotation, and stops rotating immediately when the information meeting the condition is detected, solving the problem of low efficiency and energy waste caused by blind rotation of the mobile robot when searching for a return charging point. By rotating at a preset direction and angle and stopping when valid return charging information is detected, the efficiency and accuracy of searching for a return charging point are improved, precise control and efficient operation of the mobile robot when searching for a return charging point are achieved, unnecessary rotation and energy consumption are reduced, and the overall work efficiency is improved.

[0133] Among them, the mobile robot can be first controlled to rotate at a first speed to detect whether there is an obstacle around, and if there is no obstacle and the preset rotation time and / or rotation angle are reached, the mobile robot is controlled to rotate at a second speed, wherein the first speed is less than the second speed. By controlling the mobile robot to rotate at different speeds, it can be ensured that the mobile robot is in a low-speed rotating state when encountering an obstacle, thereby protecting the mobile robot from being damaged, and also enabling the mobile robot to rotate quickly when it is determined that there is no obstacle, thereby improving the efficiency of rotation.

[0134] Further, before controlling the mobile robot to rotate, if at least part of the charging station is detected in the visual return charging signal obtained by the mobile robot, the mobile robot is controlled to rotate according to the position of the charging station in the field of view of the mobile robot, so that the charging station is located at the center of the field of view. Before rotating, the mobile robot is controlled to rotate according to the information of the detected part of the charging station, which can further accurately control the direction of the mobile robot rotation, avoid unnecessary rotation and energy consumption, and improve the overall work efficiency.

[0135] Further, before controlling the mobile robot to rotate, it can be determined whether the rotation of the mobile robot is limited due to environmental obstruction, for example, whether there is an obstacle around the mobile robot. If the rotation of the mobile robot is blocked (such as the presence of an obstacle), the mobile robot is controlled to move to a position in an open area where it can rotate freely before performing the rotation action. For example, if there is an obstacle, the mobile robot is controlled to move to an area outside the obstacle to perform the rotation action, so as to avoid the situation that the mobile robot cannot obtain return charging information due to performing the rotation action at a limited position, and ensure that the mobile robot can smoothly complete the return charging process.

[0136] Further, before controlling the mobile robot to rotate, if the mobile robot can detect at least one of the visual charging back signal, the infrared signal or the magnetic field signal, the mobile robot directly charges back using these signals without performing a rotation action. Reducing unnecessary rotation actions improves the efficiency and response speed of the mobile robot charging back.

[0137] In the method, the mobile robot can first be controlled to rotate in place, i.e., to rotate with the center of the mobile robot as the rotation center. If the first charging back information is not obtained after rotating in place, the radius of rotation is expanded, and the mobile robot is controlled to rotate at the expanded radius. By dynamically adjusting the radius of rotation, the mobile robot searches for a charging back point in a wider range, solves the problem that the mobile robot may miss a charging back point due to a limited rotation range when rotating in place, and improves the coverage and success rate of the search.

[0138] Alternatively, different rotation center positions can be set according to the way the mobile robot leaves the charging station. If the mobile robot actively leaves the charging station, the rotation center is located inside the body, i.e., the mobile robot rotates with the center of the mobile robot as the rotation center. If the mobile robot passively leaves the charging station, the rotation center is located outside the body, i.e., the radius of rotation is expanded, and the mobile robot is controlled to rotate at the expanded radius. By reasonably setting the rotation center, the mobile robot can more effectively detect visual charging back information when performing a rotation action, and the success rate of charging back is improved.

[0139] In the scheme of expanding the radius of rotation, more specifically, the mobile robot can be controlled to rotate in a spiral manner, or the mobile robot can be controlled to rotate with a position on the extension line of the wheel shafts of the two wheels of the mobile robot as the rotation center. By further refining the rotation manner after expanding the radius of rotation (including rotating in a spiral manner or rotating with a specific position as the rotation center), the mobile robot can more efficiently cover the possible charging back point area while expanding the search range, solves the problem of how to more effectively rotate to find a charging back point after expanding the radius of rotation, and improves the speed and accuracy of finding a charging back point.

[0140] In addition, the speed at which the mobile robot is controlled to rotate at the plurality of preset positions is less than the speed at which the mobile robot rotates when avoiding obstacles. For example, the speed at which the mobile robot rotates at the first preset position or the second preset position is less than the speed at which the mobile robot rotates when avoiding obstacles. When the mobile robot approaches the charging station for charging back, the rotation speed of the mobile robot at a specific preset position (such as the first preset position or the second preset position) is lower than the rotation speed when avoiding obstacles, solving the problem that the mobile robot may not accurately dock or collide with the charging station due to a too fast rotation speed. By reducing the rotation speed, the mobile robot is more stable and accurate when docking the charging station during the charging back process, and the success rate of charging back is improved.

[0141] The embodiment of the present application further provides a return charging control system of a mobile robot, which is applied to the return charging control method described above. Please refer to Fig. 11, the return charging control system 100 of the mobile robot comprises:

[0142] The judging module 101 is configured to judge whether the mobile robot has actively left the charging station before the mobile robot needs to return to charge.

[0143] The specific judging process is described above and will not be repeated here.

[0144] The moving module 102 is configured to control the mobile robot to move from the current position to the first preset position when the mobile robot has actively left the charging station before.

[0145] The acquiring module 103 is configured to acquire the return charging signal at the first preset position, and is further configured to control the mobile robot to directly acquire the return charging signal at the current position when the mobile robot has passively left the charging station before.

[0146] It should be understood that the return charging control system 100 of the embodiment can perform all the return charging control methods of the mobile robot described above, and will not be repeated here.

[0147] To solve the above technical problems, the embodiment of the present application further provides a computer device. Please refer to Fig. 12, which is a basic structure block diagram of the computer device of the embodiment.

[0148] The computer device 6 comprises a memory 61, a processor 62 and a network interface 63 which are connected to each other through a system bus. It should be pointed out that only the computer device 6 with components 61-63 is shown in the figure, but it should be understood that all the shown components are not required to be implemented, and more or fewer components can be alternatively implemented. Among them, those skilled in the art can understand that the computer device here is a device capable of automatically performing numerical calculation and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), digital signal processor (DSP), embedded device, etc.

[0149] The computer device can be a desktop computer, a notebook computer, a palm computer and a cloud server, etc. The computer device can interact with the user through a keyboard, a mouse, a remote controller, a touchpad or a voice control device, etc.

[0150] The memory 61 includes at least one type of readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory 61 can be an internal storage unit of the computer device 6, such as a hard disk or a memory of the computer device 6. In other embodiments, the memory 61 can also be an external storage device of the computer device 6, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device 6. Of course, the memory 61 can also include both an internal storage unit and an external storage device of the computer device 6. In this embodiment, the memory 61 is generally used to store an operating system installed on the computer device 6 and various information management operating systems, such as computer readable instructions of the mobile robot recharging control method, etc. In addition, the memory 61 can also be used to temporarily store various data that have been output or will be output.

[0151] The processor 62 can be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip in some embodiments. The processor 62 is generally used to control the overall operation of the computer device 6. In this embodiment, the processor 62 is used to run computer readable instructions or process data stored in the memory 61, such as computer readable instructions of the mobile robot recharging control method.

[0152] The network interface 63 can include a wireless network interface or a wired network interface, and is generally used to establish a communication connection between the computer device 6 and other electronic devices.

[0153] The present application also provides another embodiment, i.e., a computer program product storing computer readable instructions, which can be executed by at least one processor to enable the at least one processor to perform the steps of the mobile robot recharging control method as described above.

[0154] The application embodiment introduces a mobile robot back charging control method and system, including the following steps: when the mobile robot needs to be back charged, it is judged whether the mobile robot has actively left the charging station before; if the mobile robot has actively left the charging station before, the mobile robot is controlled to move from the current position to the first preset position, and the back charging signal is acquired at the first preset position; if the mobile robot has passively left the charging station before, the mobile robot is controlled to directly acquire the back charging signal at the current position. Therefore, by judging the active and passive leaving of the charging station of the mobile robot, different back charging strategies are formulated according to different ways of leaving the charging station, so that the mobile robot can correctly perform the back charging operation, unnecessary path planning and time waste are avoided, and the back charging efficiency is improved.

[0155] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment method can be realized by means of software and the necessary general hardware platform, of course, it can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a plurality of instructions for making a terminal device (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) execute the method described in each embodiment of the present application.

[0156] The technical features of the above embodiments can be combined arbitrarily, and in order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0157] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A mobile robot recharging control method, characterized by, The method comprises: When the mobile robot needs to be recharged, it is determined whether the mobile robot has left the charging station actively or passively; If the mobile robot has left the charging station actively, the mobile robot is controlled to move from the current position to the first preset position and obtain a recharging signal at the first preset position; If the mobile robot has left the charging station passively, the mobile robot is controlled to directly obtain a recharging signal at the current position.

2. The method of claim 1, wherein, The step of obtaining a recharging signal at the first preset position, or the step of controlling the mobile robot to directly obtain a recharging signal at the current position, comprises: It is determined whether the mobile robot meets a rotation condition; If the mobile robot meets the rotation condition, the mobile robot is controlled to rotate at the first preset position or at the current position to obtain the recharging signal.

3. The method of claim 2, wherein, After the mobile robot is controlled to rotate at the first preset position or at the current position, the method comprises: If the recharging signal is obtained, the mobile robot is guided to be recharged according to the recharging signal.

4. The method of claim 3, wherein, The method further comprises: If the mobile robot has left the charging station actively and the recharging signal is not obtained, the mobile robot is controlled to move to a second preset position and rotate at the second preset position to obtain the recharging signal; If the mobile robot has left the charging station passively and the recharging signal is not obtained, the mobile robot is controlled to stop moving and send a message prompt and / or a voice prompt.

5. The method of claim 4, wherein, Before the mobile robot is controlled to move to the second preset position, the method further comprises: It is determined whether the number of times of movement of the mobile robot is less than a preset number of times; If the number of times of movement is less than the preset number of times, the mobile robot is controlled to move to the second preset position; If the number of times of movement is greater than or equal to the preset number of times, the mobile robot is controlled to stop moving and send a message prompt and / or a voice prompt.

6. The method of claim 4, wherein, The second preset position and the first preset position satisfy the following relationship: AB=BC and AB perpendicular to BC, wherein the A is the position coordinate of the center of the wheel shaft of the mobile robot when it is parked on the charging station, the B is the coordinate of the first preset position, and the C point is the coordinate of the second preset position.

7. The method of claim 6, wherein, When the second preset position is two, the two second preset positions are symmetrically arranged on both sides of the first preset position.

8. The method of claim 2, wherein, If the recharging signal is still not obtained after the mobile robot is controlled to rotate at the current position, the method further comprises: The mobile robot is controlled to move to a third preset position and rotate to obtain the recharging signal.

9. The method of claim 8, wherein, If the recharging signal is still not obtained after the mobile robot is controlled to move to the third preset position and rotate, the method further comprises: At the third preset position, the mobile robot is controlled to perform a rotating action again, wherein the center of rotation of the rotating action is located outside the body of the mobile robot.

10. The method of claim 2, wherein, The step of controlling the mobile robot to rotate further comprises: controlling the mobile robot to rotate at a first speed to detect whether there is an obstacle around; if there is no obstacle and a preset rotation time and / or rotation angle is reached, controlling the mobile robot to rotate at a second speed; wherein the first speed is less than the second speed.

11. The method of claim 10, wherein, The method further comprises: if there is the obstacle, controlling the mobile robot to move to an area outside the obstacle to perform a rotating action.

12. The method of claim 2, wherein, The charging signal comprises a visual charging signal; The step of controlling the mobile robot to rotate further comprises: Before controlling the mobile robot to rotate, if there is part of the charging station information in the visual charging signal obtained by the mobile robot, controlling the mobile robot to rotate according to the charging station information, so that the charging station information is located at the center of the field of view of the visual sensor.

13. The method of claim 2, wherein, The charging signal comprises a first charging signal, a second charging signal and a third charging signal, and the first charging signal, the second charging signal and the third charging signal have an intersection; The method of judging whether the mobile robot meets the rotation condition comprises: judging whether at least one of the following signals is obtained: the first charging signal, the second charging signal and the third charging signal; if at least one of the above signals is not obtained, it is judged that the preset rotation condition is met, otherwise it is judged that the preset rotation condition is not met.

14. The method of claim 13, wherein, The first charging signal is a visual charging signal, the second charging signal is an infrared signal, the infrared signal comprises a first infrared signal and a second infrared signal, and the third charging signal is a magnetic field signal generated by the charging station, wherein the coverage area of the visual charging signal has a first intersection with the coverage area of the first infrared signal, the coverage area of the second infrared signal is in the first intersection, and the coverage area of the visual charging signal has a second intersection with the coverage area of the third charging signal; if the first infrared signal is obtained, the mobile robot is guided to move by using the first infrared signal; it is judged whether the second infrared signal, the first charging signal and / or the third charging signal is obtained; if the second infrared signal, the first charging signal and / or the third charging signal is obtained, the mobile robot is guided to continue charging according to the second infrared signal, the first charging signal and / or the third charging signal.

15. The method of claim 14, wherein, The step of guiding the mobile robot to continue charging according to the second infrared signal, the first charging signal and / or the third charging signal further comprises: a charging path is planned through the first charging signal, and the mobile robot is guided to charge according to the charging path; or, in the process of controlling the mobile robot to charge, the first charging signal is obtained in real time, and the mobile robot is guided to charge according to the first charging signal; or, based on the first charging signal, the mobile robot is controlled to move until the second infrared signal or the third charging signal is detected, and then the mobile robot is guided to charge according to the second infrared signal or the third charging signal.

16. The method of claim 14, wherein, The mobile robot comprises a first vision sensor, a second vision sensor and a third vision sensor, wherein the first vision sensor and the third vision sensor are arranged on two sides, and the second vision sensor is arranged at the front of the mobile robot, and the first vision sensor, the second vision sensor and the third vision sensor are used to acquire the first return charging signal; The step of judging whether the second infrared signal, the first return charging signal and / or the third return charging signal is acquired further comprises: If only the second infrared signal and the third return charging signal are detected, the mobile robot is controlled to rotate, and the first return charging signal is acquired by using the second vision sensor and the third sensor.

17. The method of claim 1, wherein, The step of judging whether the mobile robot is actively leaving the charging station further comprises: At least one of the following situations exists: The angle value of the IMU sensor of the mobile robot is less than a preset angle value, and / or the ground clearance sensor is not started, and the following situations exist: a next pile point is received, a work instruction is received, and an unfinished task exists; If the above situations exist, it is judged that the mobile robot is actively leaving the charging station; If the above situations do not exist, it is judged that the mobile robot is passively leaving the charging station.

18. A recharging control system for a mobile robot, the system comprising: The return charging control system comprises: A judging module is configured to judge whether the mobile robot is actively leaving the charging station when the mobile robot needs to return to charge; A moving module is configured to control the mobile robot to move from a current position to the first preset position when the mobile robot is actively leaving the charging station; An acquiring module is configured to acquire a return charging signal at the first preset position, and further configured to control the mobile robot to directly acquire a return charging signal at a current position when the mobile robot is passively leaving the charging station.

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