Mobiles Robots

Abstract

A mobile robot comprises a main body section with a plurality of drive units, each configured to generate a driving force by driving a rotating wing, and a plurality of support sections provided on the main body section and capable of supporting at least a portion of the main body section by being in contact with a predetermined contact surface, wherein, when motion control of the robot is performed while the main body section is supported by the plurality of support sections, a load exerted on the predetermined contact surface is adjusted in an assistance controller for motion control by driving the plurality of drive units via predetermined support sections that are in contact with the predetermined contact surface.

Description

[Technical field]

[0001] The present invention relates to a mobile robot capable of performing flight and movement movements. [State of the art]

[0002] In recent years, unmanned aerial vehicles (UAVs) have been used for various purposes, and their development has been actively promoted. UAVs include remotely piloted unmanned helicopters, also known as drones. Examples of drone applications in agriculture include spraying agrochemicals, monitoring crop growth with onboard cameras, and generating air currents to protect plants from frost damage (see, for example, patent literature 1). Furthermore, robots equipped with arms or similar devices have been developed to perform specific tasks and are mounted on UAVs, allowing them to be used not only for agricultural purposes but also for other applications (see, for example, patent literature 2).

[0003] Furthermore, patent literature 3 discloses a mobile robot that performs flight operations via drive units and a walking motion while standing on the ground. In this mobile robot, walking is performed by two leg sections, and if, during the walking motion, a sensor detects an increased tilt or inclination of a main body section of the robot, the robot's posture is controlled using the drive units so that the tilt remains within a predetermined angular range. [Cited Literature][Patent Literature] Patent Literature 1: Japanese Patent Application Publication No. 2018-000015 Patent literature 2: WO 2016 / 193666 Patent Literature 3: Japanese Patent No. 6733965 [Summary of the invention][Technical problem]

[0004] In a case where the main body section of the robot is moved in a state where the robot is in contact with a contact surface such as the ground, i.e., in a case where the robot's movement is performed by contact with the contact surface, such as walking, rather than by flying (in the present application, the former is referred to as "flying movement" and the latter as "contact movement"), the main body section of the robot must perform its movement while being supported by support sections (e.g., leg sections) that are in contact with the contact surface to prevent the main body section from tipping over. Generally, during contact movement at high speeds, it becomes difficult to maintain the stability of the robot's main body, thus increasing the possibility of tipping over.Furthermore, the main body section of the robot oscillates during movement, which hinders the acquisition of information about the position and attitude of the robot that is necessary for stable contact movement of the robot, so that the possibility of the robot's main body section tipping over cannot be ruled out.

[0005] The present invention was developed taking into account the problems mentioned above, and one objective of the present invention is to provide a robot technology in which a stable contact movement is achieved in a robot performing a contact movement with a contact surface by avoiding tipping over of the main body section of the robot as much as possible. [Solution to the problem]

[0006] To solve the aforementioned problems, the robot according to the present invention is provided with support sections that come into contact with a contact surface, and a configuration is used in which the drive forces are controlled by drive units. Furthermore, the robot is provided with a first control unit for the contact movement when the contact movement is performed using the support sections, and a second control unit configured to perform assistive control to support the contact movement using the drive units. With such a configuration, it is possible to achieve stable contact movement of the robot.

[0007] In detail, a mobile robot according to the present invention comprises: a main body section with a plurality of drive units, each configured to generate a driving force by driving a rotary vane; a plurality of support sections provided on the main body section and configured to come into contact with a predetermined contact surface in order to support at least a part of the main body section; a first control unit configured to perform motion control, whereby the main body section moves on the predetermined contact surface through the plurality of support sections while being supported by the plurality of support sections;and a second control unit configured to perform assistive control of the motion control by the first control unit using some or all of the plurality of drive units. The second control unit then drives the plurality of drive units in the assistive control to apply a load to the predetermined contact surface via predetermined support sections in contact with the predetermined contact surface, under the plurality of support sections. [Advantageous effects of the invention]

[0008] In a mobile robot moving in contact with a contact surface, it is possible to avoid tipping over of its main body section as much as possible in order to achieve stable contact movement. [Brief description of the drawings] Fig. Figure 1 is a view illustrating a schematic configuration of a mobile robot according to one embodiment. Fig. Figure 2 is a functional block diagram showing a picture of functional units formed in the mobile robot according to the embodiment. Fig. Figure 3 shows initial views to explain the assistance control for supporting the walking of the mobile robot. Fig. Figure 4 is a second view to explain the assistance control for supporting the walking of the mobile robot. Fig. Figure 5 is a flowchart regarding the assistance control to support the walking of the mobile robot. Fig. Figure 6 shows an initial form in which assistance control for the walking of a mobile robot is implemented. Fig. 7 are views illustrating a second form in which assistance control for the walking of a mobile robot is implemented. [Description of the embodiments]

[0009] A mobile robot of the present embodiment can generate a driving force for raising or lowering a main body section by means of a plurality of drive units provided on one side of the main body section. Each of the drive units has a rotary vane, and the driving force generated by each drive unit is determined by rotating the corresponding rotary vane. Preferably, the driving forces of the respective drive units can be controlled independently of one another. The arrangement of the plurality of drive units on the main body section can be configured in any desired way. The mobile robot can be configured to fly (ascend, descend, rotate, etc.) by balancing the driving forces of the respective drive units provided on the main body section.The numerous drive units provided on the main body section can all be of the same type or a mixture of different types.

[0010] The mobile robot is then equipped with a variety of support sections, so that its main body section is braced against a predetermined contact surface. It should be noted that the support sections can be positioned vertically or in a direction other than vertical. In the former case, the support sections can be designed as leg sections that make contact with the surface, allowing the main body section to walk on it. In the latter case, the support sections can be designed as arm sections that serve to move the main body section while it touches and grasps the surface. Configurations of the support sections other than those described above are also possible.

[0011] Here, the first control unit in the mobile robot controls the execution of a contact movement, in which the mobile robot moves on the contact surface using the multitude of support sections. The first control unit controls the drive of the multitude of support sections so that the main body section does not come into contact with the contact surface by tipping over; that is, a contact movement is executed while maintaining support from the support sections. However, when the control is performed by the first control unit, the contact between some of the multitude of support sections and the contact surface can be temporarily or intermittently broken, thus reducing the stability of the support provided to the main body section by the multitude of support sections.Such a reduction in stability does not necessarily cause the mobile robot to tip over, but it is preferable for the degree of reduction to be as small as possible. In particular, if it is difficult to predict the condition of the contact surface with which the support sections come into contact, the possibility of tipping over increases due to the primary control unit's inability to provide good control of the movement.

[0012] Therefore, if the possibility of such a tipping over increases, an assistance control for motion control is implemented by a second control unit. In this assistance control, the load transmitted to the contact surface via the support sections is adjusted by utilizing the drive forces of the multiple drive units. That is, by intentionally adjusting the load applied to each support section, the position of the pressure center of the mobile robot's support sections relative to the contact surface is shifted to a state where tipping over is unlikely. This serves the purpose of preventing tipping over.

[0013] More precisely, the second control unit can adjust the load so that the target pressure position is shifted into the interior of an actual support area if, in the motion control, the target pressure position, relative to the displacement of the center of gravity of the main body section, is not within the actual support area where the main body section is actually supported by predetermined support sections. The assistance control assumes that if a target pressure position is not within an actual support area, the support force provided by the support sections, required for stable contact movement, will be insufficient, thus increasing the possibility of tipping over. The target pressure position is a zero-moment point (ZMP) position of the mobile robot, assumed when the first control unit executes the contact movement.The actual support area is a region on the contact surface defined by the contact parts of those support sections that are in contact with the contact surface among the multitude of support sections. In this way, if a high probability of tipping is assumed due to a correlation between the target pressure position and the actual support area, the drive forces generated by driving one or more of the drive units are used to move the mobile robot's zero-point motor (ZMP) from a position corresponding to the initial target pressure position (i.e., a position outside the actual support area) to a position corresponding to the load adjustment (i.e., a position within the actual support area), thus preventing the mobile robot from tipping over.

[0014] Therefore, if a high risk of tipping is detected, load adjustment is performed using the drive forces of the drive units. This makes it possible to precisely provide the supporting force to prevent the mobile robot from tipping over, regardless of the movement or the posture / position of the support sections. This simplifies the configuration for preventing the mobile robot from tipping over, eliminating the need for sensors or similar components to ensure smooth contact movement. Even if the condition of the contact surface is not as expected, the supporting force can be precisely generated by appropriately controlling the drive units, thus achieving stable contact movement.

[0015] Specific embodiments of the present invention are described below with reference to the accompanying drawings. Unless otherwise stated, the dimensions, materials, shapes, quantities, relative arrangements, and the like of the components described in these embodiments are not intended to limit the technical scope of the present invention to these embodiments. <Ausführungsform>

[0016] Here, the following will be used as a basis for discussion: Fig. 1 and Fig. 2 an overview of a mobile robot 10 according to the present embodiment is given. Fig. Figure 1 is a view showing an external appearance of the mobile robot 10, and Fig. Figure 2 is a diagram showing functional blocks contained in the mobile robot 10. A main body section 13 of the mobile robot 10 comprises a section mainly related to the flight movement of the mobile robot 10 and a section mainly related to the walking movement of the mobile robot 10. That is, in the present embodiment, the mobile robot 10 is configured to perform both flight and walking movements.

[0017] First, a structure relating to flight movement is described. A multitude of propulsion units 12 are arranged on the main body section 13 via a multitude of bridge elements 14. It should be noted that in the Fig. In the example shown in Figure 1, four drive units 12 are attached to the main body section 13. However, as long as the mobile robot 10 is capable of flight, the number of attached drive units 12 is not limited to four, as long as there are multiple units. Furthermore, in the present embodiment, when the mobile robot 10 is in a reference position with respect to the contact surface (e.g., the ground or the like) FL, a rotor plane, formed by connecting the centers of the four drive units, is parallel to the contact surface FL, and the four drive units 12 are each arranged in rotational symmetry around the main body section 13 on the rotor plane. In other words, the four drive units 12 are arranged on the plane B in line symmetry with respect to a predetermined centerline or in point symmetry with respect to a predetermined point.It should be noted that in the reference position, all four leg sections 11, which will be described later, are in a predetermined state, so that the main body section 13 is not inclined with respect to the contact surface FL. It should also be noted that reference symbols 12a to 12d are used when individually referring to the drive units 12.

[0018] The drive units 12 each comprise a propeller, which is a rotating blade, and an actuator for rotating the propeller. All four drive units 12 are of the same type, but the actuators in each drive unit 12 can be controlled independently. Therefore, it is possible to appropriately control the propulsive force generated by each drive unit 12, thus enabling appropriate control of the flight attitude, flight speed, and the like of the mobile robot 10. As described later, the actuators in each drive unit 12 can also be controlled independently during assistive control when the mobile robot 10 performs a walking motion. Furthermore, the mobile robot 10 is equipped with a sensor 15 required for its flight motion (flight sensor), sensors 16 required for its walking motion (contact sensors), and a battery 17 (see Fig. 2) equipped for supplying the sensors and actuator of each drive unit 12 with drive energy and a control device for controlling the energy supply from the battery 17 to each actuator. The control device integrates two controllers, a first controller 100 and a second controller 200, the details of which will be described later.

[0019] Next, a structure relating to walking motion is described. The mobile robot 10 has leg sections 11 (four legs) configured to perform the walking motion. It should be noted that in the Fig. In the example shown, four leg sections 11 are provided on the main body section 13, but the number of leg sections 11 is not limited to four as long as walking is possible, and two or three leg sections 11 may be provided, or five or more leg sections 11 may be provided. It should be noted that in a case where the leg sections 11 are designated individually, reference numerals 11a to 11d are used.

[0020] As an example for leg sections 11, in Fig. Figure 1 shows an enlarged view of a leg section 11. Each leg section 11 has a ground contact section that comes into contact with the ground when the mobile robot 10 walks, a connecting section that is rotatably linked to the ground contact section via a joint, a hip joint section that is rotatably linked to the connecting section via a joint, and a plurality of actuators (not shown) that drive and control the rotation of each joint. The joint connected to the connecting section is configured according to the assumed walking motion with respect to its directions of rotation (i.e., directions of rotation about a roll axis and a pitch axis). It should be noted that the configuration of each leg section 11 is not limited to such an example.Furthermore, each hip joint segment is connected to a bottom surface of the main body segment 13 via a predetermined joint, allowing it to rotate relatively. This predetermined joint is configured to rotate about a yaw axis. The predetermined joint can also be configured to rotate about a roll axis and a pitch axis.

[0021] The leg sections 11, configured as described above, form a structure that enables the walking movement of the mobile robot 10 while supporting the robot's own weight against the contact surface FL during the walking movement. Therefore, the four leg sections 11 function as support sections of the present invention for realizing the walking movement, which is inherent in the type of movement. Furthermore, unlike flight, the movement of the mobile robot is performed in a state where at least one of the four leg sections 11 is in contact with the contact surface FL to support the main body section 13. Therefore, the walking movement is also a type of movement inherent in the contact movement. <Steuereinheit des mobilen Roboters 10>

[0022] Next, the control configuration of mobile robot 10 will be described using... Fig. 2. The mobile robot 10 has a control device comprising a first control unit 100, a second control unit 200, and a detection unit 300. The control device is a computer with a processing unit and memory. Each functional unit is formed by executing a predetermined control program in the mobile robot 10.

[0023] First, the first control unit 100 is described. The first control unit 100 is a functional unit for executing walking and flying movements in the mobile robot 10 using the leg sections 11 and the drive units 12. That is, the first control unit 100 controls the actuators provided on the leg sections 11 for walking movements and also controls the drive units 12 for flying movements. The first control unit 100 controls the driving forces of the four drive units 12 based on environmental information relating to the flight state of the mobile robot 10, which is acquired by the flight sensor 15.Such environmental information can include, for example, information about the angular velocity of the main body section 13, detected by a gyroscope along three axes not shown (a yaw axis, a pitch axis, and a roll axis); the tilt or inclination of the main body section 13, detected by an accelerometer along the same three axes not shown; and the like. The first control unit 100 performs feedback control using the environmental information detected by these sensors, ensuring that the tilt of the main body section 13 of the mobile robot 10 is in a state suitable for flight. Furthermore, the environmental information can include an azimuth angle, which determines the orientation of the main body section 13 (i.e.,the orientation of the main body section of the mobile robot 10) in the absolute coordinate system is when the orientation of the Earth's axis is set as a reference, and the azimuth angle can be detected by an azimuth angle sensor.

[0024] When the main body section 13 of the mobile robot 10 is to fly forward, backward, left, and right, the first control unit 100 reduces the rotational speed of the actuator of a drive unit 12 in the direction of travel and increases the rotational speed of the actuator of a drive unit 12 on the opposite side of the direction of travel, so that the main body section of the mobile robot 10 assumes a forward-tilted position relative to the direction of travel and thus moves in the desired direction. Similarly, when the main body section of the mobile robot 10 is rotated and made to fly, the first control unit 100 supplies the power to each propeller 21 according to its direction of rotation, based on the direction of rotation of the main body section 13 of the mobile robot 10.For example, if the main body section 13 of the mobile robot 10 is rotated to the right, the first control unit 100 reduces the power of the actuator corresponding to the propeller rotating to the right and increases the power of the actuator corresponding to the propeller rotating to the left.

[0025] Furthermore, a walking movement executed by the first control unit 100 is described. The first control unit 100 is also a functional unit that, when the mobile robot 10 is walking, controls an actuator provided for walking on each of the four leg sections 11. The first control unit 100 uses environmental information acquired by the contact sensors 16, which indicates whether the ground contact section of each leg section 11 is in contact with the contact surface FL when the walking movement is executed. It should be noted that, in the present embodiment, a predetermined walking control program for walking on the contact surface FL, used by the first control unit 100, utilizes the acquisition values ​​from the contact sensors 16 by minimizing the acquisition of information about the environment of the mobile robot 10, in order to simplify and facilitate the walking control of the mobile robot 10.

[0026] More precisely, the actuator provided at each joint of the leg sections 11 is equipped with an encoder (not shown) that detects state variables (a rotational position, a rotational speed, and the like of a rotating shaft of the actuator) with respect to each rotational state. It should be noted that a sensor other than the encoder can be used. The first control unit 100 then performs feedback control of the actuators of the leg sections 11 based on the state variables of each actuator detected by the actuator's encoder, so that the walking movement of the mobile robot 10 is realized according to a motion instruction given to the mobile robot 10. As described above, in the present embodiment, the feedback control of the actuators relies as little as possible on environmental information outside the robot.This allows the sensors to be attached to the mobile robot 10 to be omitted as much as possible and the walking control itself to be simplified.

[0027] Furthermore, during walking control, the contact sensors 16 detect whether the ground contact sections of the respective leg sections 11 are in contact with the contact surface FL or not. The fact that a leg section 11 is not in contact with the contact surface FL means that the main body section 13 of the mobile robot 10 is not supported by a reaction force from the contact surface FL via this leg section 11. Thus, if the main body section 13 of the mobile robot 10 is not supported by the leg section 11, the stability of the main body section 13 can change, and in some cases, the possibility of the main body section 13 tipping over increases. In such a case, in the present embodiment, the assistance control is carried out by the second control unit 200 (corresponding to the "assistance control for walking control" according to the present invention). <assistenzsteuerung>

[0028] The following describes the assistance control provided by the second control unit 200. Here, a change in the stability of the main body section 13 during walking control (when the mobile robot 10 performs the walking movement) is described using... Fig. 3 described. For the sake of simplicity, it is assumed that the mobile robot 10 is in a static state. In a case where the mobile robot 10 is in a dynamic state, i.e., in a case where it is subject to acceleration / deceleration, disturbance, or the like, a required force and / or torque is taken into account in addition to gravity. The upper part (a) of Fig. Figure 3 shows a state in which the four leg sections 11 of the mobile robot 10 are in contact with the contact surface FL, and the lower part (b) shows a state in which one leg section 11a is separated or removed from the contact surface FL. The state in which leg section 11a is separated from the contact surface FL is detected by the contact sensor 16 of leg section 11a. Here, it is assumed that the mobile robot 10 is performing a walking motion with a workpiece W mounted on it.

[0029] Here, for the leg sections 11, whose ground contact sections are actually in contact with the contact surface FL, a closed area designed to encompass the contact points is defined as the actual support area SS. For example, the actual support area SS can be a polygonal area with the contact points as its vertices. In this case, Fig. 3 (a) the actual support area SS is formed in a square shape, and in Fig. 3 (b) the actual support area SS is formed in a triangular shape. Additionally, the actual support area SS can be formed in shapes that differ from those shown in Figure 3(b) to provide suitable support for the mobile robot 10. Fig. The shapes shown in 3 (a) and (b) are further reduced inwards. It should be noted that the second control unit 200 can determine the position of the contact point of each leg section 11 from the detection value of each contact sensor 16 and the state (position) of the actuator of each leg section 11 when its contact state is detected.

[0030] When the mobile robot 10 then executes a walking control using its four leg sections 11, a path along which the center of gravity of the mobile robot 10 should be located during the walking movement is given as a position command to the first control unit 100, and each leg section 11 is driven to follow the position command. At this point, the position of an ideal center of gravity, calculated from the path or similar of the mobile robot 10, is defined as the target pressure position PP. The load of the workpiece W carried by the mobile robot 10 is also taken into account for the target pressure position PP. Then, during the walking control, as described in Fig. 3 (a) shows that when the target pressure position PP is within the actual support area SS, the mobile robot 10 is stably supported by the four leg sections 11. However, if, as in Fig. As shown in Figure 3(b), if the target pressure position PP is not within the actual support area SS, the mobile robot 10 is not stably supported by the three leg sections 11b, 11c, 11d. Consequently, the mobile robot 10 may tip over in this case.

[0031] To prevent tipping, which can occur when the target pressure position PP deviates from the actual support region SS, four drive units 12 are used in the present embodiment to adjust the load via the leg sections 11 that are in contact with the contact surface FL. This load adjustment shifts the actual position of the pressure center of the mobile robot 10 relative to the contact surface FL, thereby moving the target pressure position PP into the actual support region SS and preventing the mobile robot 10 from tipping over. This load adjustment is achieved by means of Fig. 4 described. The state of the mobile robot 10, which is in the upper part (a) of Fig. The one shown in 4 is the same as the one in Fig. 3 (b) shown, and the leg sections 11b, 11c, 11d are in contact with the contact surface FL, and a triangular actual support area SS is formed by connecting the respective contact points 11b1, 11c1, 11d1. The intended pressure position PP is located outside the actual support area SS.

[0032] Furthermore, the lower part (b) of Fig. Figure 4 shows a top view of the contact surface FL, illustrating the correlation between the actual support area SS and the target pressure position PP. During load adjustment for the assistance control, the drive control of the four drive units 12 is performed such that the target pressure position PP, which lies outside the actual support area SS, falls within the actual support area SS. Fig. Figure 4(b) shows the target pressure position after load adjustment by PP1. It should be noted that a certain margin of safety (stability margin) is preferably provided at this point so that the adjusted target pressure position PP1 does not immediately deviate from the actual bearing surface due to external disturbances or the like. That is, the load adjustment is carried out such that a section of a certain size, centered on the target pressure position itself, lies within the actual bearing surface SS.

[0033] More precisely, since the total sum of the reaction forces transmitted from the contact surface to the leg sections 11 and the load increased or decreased by the drive units 12 is equal to the force of gravity, the following formula applies: 1. The load increased or decreased by the drive units 12 is considered as an increase or decrease in the virtual weight (mass) of the mobile robot 10 and is referred to as the “gravitational load due to the virtual mass”. [Mat. 1] case=0=∑i=14fRi+∑i=1nfVgAi−mg=∑i=14fRi+∑i=14fri−mg where fRi represents a reaction force transferred to each leg section 11, fVgAi represents the gravitational load due to the above-mentioned virtual mass, and fRi represents a rotor thrust force.

[0034] Furthermore, the following formula 2 applies from the equilibrium of the moment about the center of gravity of the mobile robot 10. [Math. 2] Mall=0=∑i=14rRi×fRi+∑i=14rri×fri =∑i=14rRi×fRi+∑i=14rVgAi×fVgAi where rRi represents the position of the ground contact section of each leg section and rri represents the position of each drive unit 12. Furthermore, rVgAi represents the position of the virtual mass.

[0035] When the mobile robot 10 is in a static state, the average of the center of gravity (the center of gravity corresponding to the target pressure position PP) of the mobile robot 10 and the position of the virtual mass is the center of gravity of the mobile robot after load adjustment, and a point where it is projected onto the contact surface FL is the target pressure position PP1 after load adjustment. Thus, the load exerted on the target pressure position PP1 is the sum of the mobile robot 10's own weight and the gravitational load caused by the virtual mass. Based on the above, the gravitational load caused by the virtual mass and the position of the virtual mass are calculated such that Formula 1 and Formula 2 are satisfied and the target pressure position PP1 after load adjustment lies within the actual support area.Then, a rotor thrust force capable of realizing the virtual mass is calculated from formula 2, and a drive command is issued to each drive unit 12. As a result, the assistance control is executed by the second control unit 200, thereby improving the stability of the walking motion of the mobile robot 10 compared to the case where the assistance control is not executed.

[0036] Furthermore, as described above, a stable walking motion is achieved even though only a few sensors are used, as the use of environmental information for the walking control of the mobile robot 10 is suppressed as much as possible.

[0037] Next, the detection unit 300 is described. The detection unit 300 is a functional unit that detects frictional conditions on the contact surface FL and processes, for example, images of the contact surface FL taken by a camera on the mobile robot 10 to determine the dryness level and the condition of the surface of the contact surface FL, thus detecting the frictional conditions. Generally, if the contact surface FL is wet due to rain, snow, or the like, its coefficient of friction with the mobile robot 10 decreases, which can affect the stability of its walking motion. Conversely, if a highly viscous material is present on the contact surface FL, the coefficient of friction increases excessively due to the material's influence, which can also affect the stability of the walking motion.

[0038] Therefore, the assistance control is based on the friction state detected by the detection unit 300 with reference to Fig. 5 described. The in Fig. The assistance control shown in section 5 is executed repeatedly by the second control unit 200 at predetermined time intervals. First, S101 determines whether the current target print position PP is within the actual support area SS. If the determination is positive, the operation of S103 is executed; if negative, the operation of S102 is executed. Note that an example of a negative determination is shown in Fig. The state shown in 4(a) is present. Then, in S102, after a negative determination, a load adjustment is carried out using the drive units 12, as described above, so that the adjusted target pressure position PP1 lies within the actual support area SS, as shown in Fig. 4 (b) shown.

[0039] Subsequently, the detection unit 300 in S103 detects the friction state at the contact surface FL. As described above, the friction state is detected by image processing of the camera's imaging results to determine whether there is water or snow on the contact surface FL that could cause the robot to tip over, or whether substances or similar materials are adhering to the contact surface FL that could lead to increased friction. Then, in S104, based on the friction state obtained from the imaging results, it is determined whether a load readjustment is necessary. That is, if the friction condition detected by the detection unit 300 deviates from an expected friction condition by a predetermined threshold or more, it is assumed that the deviation could have a non-negligible influence on the walking motion of the mobile robot 10.Therefore, in such a case, it is determined that not only the load adjustment in S102, but also the readjustment of the load is necessary (affirmative finding).

[0040] If a positive finding is made in S104, the process continues to S105, where the load readjustment is performed using the drive units 12. The load readjustment performed in S105 is a load adjustment superimposed on the load adjustment performed in S102. For example, based on the difference in friction conditions obtained as a result of the detection by the detection unit 300, the gravity load due to the virtual mass and the position of the virtual mass, which should be increased to ensure the expected frictional force, are calculated. At this point, it should be noted that the target pressure position after the readjustment is within the actual support area SS. When the processing in S105 is complete, the Fig. The assistance control described in section 5 is repeated from the beginning. Thus, according to the instructions in section 5, the assistance control is repeated from the start. Fig. The assistance control shown in Figure 5 supports the walking control of the mobile robot 10, taking into account the state of the contact surface FL, so that the stability of the walking movement of the mobile robot 10 is further improved. <Modifizierte Ausführungsform 1>

[0041] A first form of support state by the leg sections 11 during the walking movement of the mobile robot 10 is demonstrated by Fig. 6 described. It should be noted that in Fig. 6. The walking movement is performed on a contact surface that is not a flat surface, but is in a so-called uneven ground condition. The upper part (a) of Fig. Figure 6 shows a state in which the main body section 13 of the mobile robot 10 is supported using all four leg sections 11. Furthermore, the middle section (b) shows a state in which three of the four leg sections 11 are used to support the main body section 13 of the mobile robot 10, in particular, leg section 11a being separated from the contact surface and the main body section 13 being supported by the other leg sections 11b, 11c, and 11d. Additionally, the lower section (c) shows a state in which the main body section 13 of the mobile robot 10 is supported using two of the four leg sections 11, in particular, leg sections 11a and 11c being separated from the contact surface and the main body section 13 being supported by the other leg sections 11b and 11d.

[0042] The state in which the main body section 13 is supported by the four leg sections 11 is the most stable state. However, if the contact surface is uneven, as in the present configuration, the target pressure position PP may deviate from the actual support area SS due to an inclination or tilt of the mobile robot 10, or similar factors. In such a case, the assistance control for gait control described above can be performed by the second control unit 200. The same applies in this respect if three leg sections 11 are providing support.

[0043] Here's how in Fig. Figure 6(c) shows that, in the case of support by two leg sections 11, the actual support area SS, formed by the leg sections 11b and 11d in contact with the contact surface, is a straight line connecting their respective contact points. In such a case, if the target pressure position PP lies on the straight line, it is determined that the target pressure position PP is within the actual support area SS, and if the target pressure position PP deviates from the straight line, it is determined that the target pressure position PP is not within the actual support area SS. Then, in the latter case, the assistance control for the running control can be performed by the second control unit 200 described above.

[0044] The walking movement of the mobile robot 10 does not necessarily have to be performed using the four leg sections 11. For example, depending on the shape and inclination of the contact surface, two of the four leg sections 11a, 11c can always be kept separated from the contact surface, and the remaining two leg sections 11b, 11d can be used for walking. That is, the walking movement should be performed using the number of leg sections that is best suited to the nature of the contact surface, and if the mobile robot 10 cannot be stably supported by these leg sections, the assistance control for the walking movement should be performed by the second control unit 200 described above. <Modifizierte Ausführungsform 2>

[0045] Next, using Fig. 7 a second form of support state by the leg sections 11 at the time of the walking movement of the mobile robot 10 is described. The upper part (a) of Fig. Figure 7 shows a state in which the main body section 13 of the mobile robot 10 is supported using all four legs 11 and an end effector 20, which originally has a holding or gripping mechanism for holding or grasping an object. The number of contact points supporting the main body section 13 is increased by the contact between the end effector 20 and the contact surface, thus increasing the actual support area SS. This increases the probability that the target pressure position PP will fall within the actual support area SS, resulting in a more stable walking motion. Even in such a case, the assistance control for the walking control can be performed by the second control unit 200 described above if the target pressure position PP deviates from the actual support area SS.

[0046] Furthermore, the middle section (b) discloses a condition in which the main body section 13 of the mobile robot 10, in addition to all four leg sections 11, is supported by an object 20a grasped or held by the end effector 20. In this case, an actual support area SS is formed using a contact point between the object 20a held by the end effector 20 and the contact surface. For example, when the mobile robot 10 walks with the object 20a, stable walking motion can be achieved using the object. Even in such a case, the assistance control for walking control by the second control unit 200, as described above, can be performed if the target pressure position PP deviates from the actual support area SS.

[0047] Furthermore, the lower part (c) discloses a state in which the main body section 13 of the mobile robot 10, in addition to two leg sections 11c, 11d, is supported beneath the four leg sections 11 by a support section 11e. Unlike the leg sections 11, the support section 11e is not used directly for walking but is configured to support the main body section 13 during walking. The auxiliary support section 11e is a structure that does not have a joint or an actuator for driving the joint, as in the leg sections 11, but is configured to maintain contact with the contact surface by applying a specific load to it. Again, an actual support area SS is formed by using a contact point between the auxiliary support section 11e and the contact surface.The support force of the auxiliary support section 11e may in some cases be weaker than the support force provided by the leg sections 11, but if, for example, one compares the case of walking with the two leg sections 11c and 11d with the case of walking with the auxiliary support section 11e added, the actual support area SS can be increased in the latter case, thereby achieving a stable walking motion. Even in such a case, if the target pressure position PP deviates from the actual support area SS, the assistance control for gait control can be performed by the second control unit 200 described above. [List of reference symbols]

[0048] 10 ... mobile robot; 11, 11a, 11b, 11c, 11d ... leg sections; 11e ... auxiliary support section; 12, 12a, 12b, 12c, 12d ... drive units; 13 ... main body section; 14 ... bridge elements; 15 ... flight sensor; 16 ... contact sensor; 17 ... battery; 20 ... end effector; 20a ... object; 100 ... first control unit; 200 ... second control unit; FL ... contact area; PP ... target pressure position; SS ... actual support area. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2018-000015

[0003] WO 2016 / 193666

[0003] JP 6733965

[0003] < / assistenzsteuerung>

Claims

[1] Mobile robot, comprehensive: a main body section with a multitude of drive units, each configured to generate a driving force by driving a rotary wing; a multitude of support sections provided on the main body section and configured to come into contact with a predetermined contact surface in order to support at least part of the main body section; a first control unit configured to perform motion control for moving the main body section on the predetermined contact surface through the plurality of support sections, while the main body section is supported by the plurality of support sections; and a second control unit configured to perform assistive control of the motion control by the first control unit using some or all of the drive units; wherein the second control unit drives the plurality of drive units in the assistance control to adapt a load which is exerted on the predetermined contact surface under the plurality of support sections via predetermined support sections that are in contact with the predetermined contact surface. [2] The mobile robot according to claim 1, wherein the second control unit adjusts the load such that if a target pressure position relating to a displacement of the center of gravity of the main body section in the motion control is not within an actual support area in which the main body section is actually supported by the predetermined support sections, the target pressure position is shifted within the actual support area. [3] The mobile robot according to claim 2, further comprising a detection unit configured to detect a friction state at the predetermined contact surface, wherein the second control unit adjusts the load based on the friction state detected by the detection unit. [4] The mobile robot according to any one of claims 1 to 3, wherein In a case where the number of predetermined support sections in contact with the predetermined contact area among a plurality of support sections is three or more, the actual support area is a polygonal area formed by connecting contact points between each of the predetermined support sections and the predetermined contact area; and In a case where the number of predetermined support sections in contact with the predetermined contact surface among a plurality of support sections is two, the actual support area is a straight-line area formed by connecting contact points between each of the two predetermined support sections and the predetermined contact surface. [5] The mobile robot according to any one of claims 1 to 3, wherein the plurality of drive units are arranged in line symmetry or point symmetry with respect to the main body section when viewed from the direction of gravity of the main body section. [6] The mobile robot according to any one of claims 1 to 3, wherein the plurality of support sections are a plurality of leg sections attached to the main body section in such a way that they can bear the weight of the main body section. [7] The mobile robot according to claim 6, wherein the plurality of support sections further comprises a holding section which can hold an object, or the object held by the holding section in such a way that it can come into contact with the predetermined contact surface.