CN115344040A - Method and device for foot end trajectory planning of a legged robot and the legged robot - Google Patents

Abstract

The application discloses a method and a device for planning foot end tracks of a foot-type robot and the foot-type robot, which are used for enabling the robot to stably climb up and down steps and cross over obstacles, reducing collisions and improving the stability of the robot in the processes of ascending and descending steps and crossing over obstacles. The method comprises the following steps: determining the swing height and the swing length of the foot end of at least one leg, which is lifted from the first step to the second step in the first swing phase; if the tread of the second step is higher than that of the first step, determining a first series of track traction points corresponding to the foot end according to the swing height and the swing length; generating a first foot end track according to the first series of track traction points to control the foot end to fall on the second step; if the tread of the second step is lower than that of the first step, determining a second series of track traction points corresponding to the foot end according to the swing height and the swing length; and generating a second foot end track according to the second series of track traction points to control the foot end to fall on the second step.

Description

Method and device for foot end trajectory planning of a legged robot and the legged robot

technical field

The present application relates to the technical field of robot control, in particular to a method and device for foot trajectory planning of a legged robot and a legged robot.

Background technique

With the improvement of computer performance, the development of sensor technology, and the continuous improvement of robot technology, various robots have gradually appeared in human life to help humans complete specific tasks. Footed robots (bipedal, quadrupedal and multi-legged robots) Compared with traditional wheeled robots and tracked robots, the biggest advantage of footed robots is the wide range of their passable areas, which can go up, Descending stairs is an incomparable advantage of legged robots over other robots. How to make legged robots go up and down stairs reliably and safely is an urgent problem to be solved for legged robots.

In the prior art, legged robots widely use one-time Bezier curves for trajectory planning when the robot goes up and down stairs. However, due to its too simple curve shape, it is difficult to cope with the randomness of the foot end point in the stair position during the stair climbing process. For example, when the robot goes up and down the stairs, if the starting point or foothold is close to the edge of the stairs, the legs may collide with the stairs, which may further cause the robot to lose stability and fall.

Contents of the invention

This application provides a method and device for foot trajectory planning of a legged robot and a legged robot, which are used to enable the robot to smoothly go up and down steps and cross obstacles, reduce bumps, and improve the robot's ability to move up and down steps and cross obstacles. stability.

The first aspect of the present application provides a method for foot trajectory planning of a legged robot, including:

Determine the swing height and swing length of the foot end of at least one leg in the first swing phase from the first step to the second step, the first step being the foot end of the supporting leg in the first support phase The step where the time is, the first support phase and the first swing phase are continuous in time, and the first support phase is earlier than the first swing phase;

If the tread of the second step is higher than the tread of the first step, then determine the first series of trajectory traction points corresponding to the foot end according to the swing height and swing length;

generating a first foot end trajectory according to the first series of trajectory traction points, and controlling the foot end to land on the second step according to the first foot end trajectory;

If the tread of the second step is lower than the tread of the first step, then determine the second series of track traction points corresponding to the foot end according to the swing height and swing length;

A second foot end trajectory is generated according to the second series of trajectory traction points, and the foot end is controlled to land on the second step according to the second foot end trajectory.

Optionally, the first series of trajectory traction points include: at least one traction point of the first foot end retraction and at least one first foot end forward swing traction point;

The at least one first foot end retraction traction point is used to pull the foot end back during the lifting process of the foot end, so as to prevent the foot end from touching the kicking surface of the second step during the lifting process;

The at least one first foot end forward swing traction point is used to pull the foot end forward swing and bypass the edge of the second step after the foot end is raised higher than the tread height of the second step;

The second series of track traction points include: at least one second traction point for the forward swing of the foot end and at least one traction point for the second retraction of the second foot end;

The at least one second traction point for forward swing of the foot end is used for pulling the forward swing of the foot end during the lifting process of the foot end and bypassing the edge of the first step;

The at least one second foot-end retraction traction point is used for pulling the foot-end to retract during the falling process of the foot-end, so as to prevent the foot-end from touching the edge of the second step during the falling process.

Optionally, the first series of trajectory traction points further include: at least 1 first foot-end speed traction point, the at least 1 first foot-end speed traction point is used to connect the foot end with the second step When the distance of the tread on the second step is less than the preset distance, the traction foot end reduces the speed and/or acceleration of the tread on the second step;

The second series of track traction points also includes: at least one second foot-end speed traction point, the at least one second foot-end speed traction point is used for the distance between the foot end and the tread surface of the second step When the distance is less than the preset distance, the traction foot end reduces the speed and/or acceleration of the tread on the second step.

Optionally, before the determination of the first series of trajectory traction points corresponding to the foot end according to the swing height and swing length, the method further includes:

Judging whether there is an intersection between the original foot track and the riser or tread of the second step;

The determining the first series of track traction points corresponding to the foot end according to the swing height and swing length includes:

If there is an intersection, then determine the first series of trajectory traction points corresponding to the foot end according to the swing height and swing length;

or,

Before the determination of the second series of trajectory traction points corresponding to the foot end according to the swing height and swing length, the method further includes:

Judging whether there is an intersection between the original foot track and the riser or tread of the first step;

The determining the second series of track traction points corresponding to the foot end according to the swing height and swing length includes:

If there is an intersection, a second series of trajectory traction points corresponding to the foot end are determined according to the swing height and swing length.

Optionally, before the determination of the first series of trajectory traction points corresponding to the foot end according to the swing height and swing length, the method further includes:

judging whether the distance between the foot end and the rising surface of the second step is less than a preset distance;

The determining the first series of track traction points corresponding to the foot end according to the swing height and swing length includes:

If less, determine the first series of trajectory traction points corresponding to the foot end according to the swing height and swing length.

Optionally, the determination of the swing height and swing length of the foot end of at least one leg in the first swing phase from lifting from the first step to falling to the second step includes:

If the robot is in the blind climbing mode, receive an instruction to filter the target staircase size information in the preset staircase size table, and determine that the foot end of at least one leg is lifted from the first step in the first swing phase according to the target staircase size information The swing height and swing length to fall to the second step;

or,

If the robot is in the visual mode, then determine the swing height and swing length of the foot end of at least one leg in the first swing phase from lifting from the first step to falling to the second step according to the visual information of the robot.

The second aspect of the present application provides a method for foot trajectory planning of a legged robot, including:

When an obstacle is sensed, determine attribute information of the obstacle, where the attribute information includes shape and size information;

judging whether a preset track switching condition is met according to the attribute information;

If so, determine the swing height and length from the starting point to the foothold point of the foot end of at least one leg in the second swing phase according to the attribute information, and the starting point is that the foot end of the supporting leg is in the second support phase. time position, the second support phase and the second swing phase are continuous in time, and the second support phase is earlier than the second swing phase;

A third foot end trajectory is generated according to the third series of trajectory traction points, and the foot end is controlled to cross the obstacle according to the third foot end trajectory.

Optionally, the third series of trajectory traction points includes a first combined traction point and a second combined traction point;

The first combined traction point includes at least one traction point where the third foot end is lifted and retracted, at least one traction point where the third foot end is swung forward, and at least one traction point where the third foot end is dropped and retracted;

The second combined traction point includes at least one traction point for raising and retracting the third foot end and at least one traction point for swinging the third foot end forward;

The at least one third foot-end lifting and retracting traction point is used for pulling the foot-end to retract during the lifting process of the foot-end, so as to prevent the foot-end from touching the obstacle during the lifting process;

The at least one third foot end forward swing traction point is used to pull the foot end forward swing and bypass the edge of the obstacle after the foot end is lifted higher than the obstacle;

The at least one third foot-end retraction traction point is used for pulling the foot-end to retract during the falling process of the foot-end, so as to prevent the foot-end from touching the edge of the obstacle during the falling process.

Optionally, the judging whether a preset track switching condition is met according to the attribute information includes:

According to the attribute information, it is judged whether there is an intersection between the original foot track and the obstacle, and if there is, it is determined that the preset track switching condition is met;

or,

According to the attribute information, it is judged whether the distance between the starting point in the original foot-end trajectory and the obstacle is less than a preset distance, and if it is smaller, it is determined that the preset trajectory switching condition is met.

The third aspect of the present application provides a foot trajectory planning device for a legged robot, the device includes: a sensing unit and a control unit;

The sensing unit is used for:

Determine the swing height and swing length of the foot end of at least one leg in the first swing phase from the first step to the second step, the first step being the foot end of the supporting leg in the first support phase The step where the time is, the first support phase and the first swing phase are continuous in time, and the first support phase is earlier than the first swing phase;

The control unit is used for:

If the tread of the second step is higher than the tread of the first step, then determine the first series of trajectory traction points corresponding to the foot end according to the swing height and swing length;

generating a first foot end trajectory according to the first series of trajectory traction points, and controlling the foot end to land on the second step according to the first foot end trajectory;

If the tread of the second step is lower than the tread of the first step, then determine the second series of track traction points corresponding to the foot end according to the swing height and swing length;

A second foot end trajectory is generated according to the second series of trajectory traction points, and the foot end is controlled to land on the second step according to the second foot end trajectory.

The fourth aspect of the present application provides a device for planning foot trajectory of a legged robot, the device comprising: a sensing unit and a control unit;

The sensing unit is used for:

When an obstacle is sensed, determine attribute information of the obstacle, where the attribute information includes shape and size information;

The control unit is used for:

judging whether a preset track switching condition is met according to the attribute information;

The sensing unit is further configured to: when the control unit judges according to the attribute information that the preset trajectory switching condition is satisfied, determine according to the attribute information that the foot end of at least one leg is in the second swing phase, from the starting point The swing height and swing length to the foothold point, the starting point is the position where the foot end of the supporting leg is in the second support phase, the second support phase and the second swing phase are continuous in time, and the said second strut phase is earlier than said second swing phase;

The control unit is also used for:

Determine the third series of trajectory traction points corresponding to the foot end according to the swing height and swing length;

A third foot end trajectory is generated according to the third series of trajectory traction points, and the foot end is controlled to cross the obstacle according to the third foot end trajectory.

A fifth aspect of the present application provides a legged robot, the legged robot comprising:

Processor, memory, I/O unit and bus;

The processor is connected to the memory, the input and output unit and the bus;

The memory stores a program, and the processor invokes the program to execute the first aspect and any optional method for foot trajectory planning of the legged robot in the first aspect.

As can be seen from the above technical solutions, the present application has the following advantages:

When the legged robot goes up and down steps or crosses obstacles, the legged robot will design different types and variable number of trajectory traction points according to different obstacle types, and then generate the foot trajectory of the robot based on the designed trajectory traction points, so that The designed foot trajectory, that is, the first foot trajectory, the second foot trajectory and the third foot trajectory in this application, can avoid the collision between the robot foot and the steps or obstacles, so that the robot can go up smoothly. Go down steps and cross obstacles to improve the stability of the robot during travel.

Description of drawings

In order to illustrate the technical solutions in this application more clearly, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the application. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Figure 1-a and Figure 1-b are schematic diagrams of the hardware structure and mechanical structure of the legged robot provided by the present application;

Fig. 2-a is a schematic diagram of the upper step scene flow in the method for foot end trajectory planning of the legged robot provided by the present application;

Figure 2-b is a schematic diagram of the first series of trajectory traction points and the first foot end trajectory in the method for foot end trajectory planning of a legged robot provided by the present application;

Fig. 3-a is a schematic flow diagram of the step-down scene in the method for foot trajectory planning of the legged robot provided by the present application;

Figure 3-b is a schematic diagram of the second series of trajectory traction points and the second foot end trajectory in the method for foot end trajectory planning of a legged robot provided by the present application;

Figure 4-a is a schematic flow diagram of the obstacle-crossing scene in the method for foot trajectory planning of the legged robot provided by the present application;

Figure 4-b is a schematic diagram of the third series of trajectory traction points and the third foot end trajectory in the method for foot end trajectory planning of a legged robot provided by the present application;

Fig. 5 is a schematic structural diagram of an embodiment of a legged robot provided by the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the present invention, rather than all of them. example. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that the present application provides a method and device for foot trajectory planning of a legged robot, and the legged robot. The following will describe the hardware structure and mechanical structure of the robot provided by this application. In the following description, use of suffixes such as 'module', 'part' or 'unit' for denoting components is only for facilitating description of the present invention and has no specific meaning by itself. Therefore, 'module', 'part' or 'unit' may be used in combination.

Please refer to FIG. 1-a. FIG. 1-a is a schematic diagram of the hardware structure of a multi-legged robot 100 according to one embodiment of the present invention. In the embodiment shown in FIG. 1-a , the multi-legged robot 100 includes a mechanical unit 101 , a communication unit 102 , a sensing unit 103 , an interface unit 104 , a storage unit 105 , a control unit 110 , and a power supply 111 . The various components of the multi-legged robot 100 may be connected in any manner, including wired or wireless connections, and the like. Those skilled in the art can understand that the specific structure of the multi-legged robot 100 shown in FIG. Certain components are not essential components of the multi-legged robot 100 , and can be omitted or combined as required without changing the essence of the invention.

The various components of the multi-legged robot 100 are specifically introduced below in conjunction with FIG. 1-a:

The mechanical unit 101 is the hardware of the multi-legged robot 100 . As shown in Fig. 1-a, the mechanical unit 101 may include a driving board 1011, a motor 1012, and a mechanical structure 1013. As shown in Fig. part 1016, in other embodiments, the mechanical structure 1013 can also include an extendable mechanical arm (not shown), a rotatable head structure 1017, a swingable tail structure 1018, a loading structure 1019, and a saddle structure 1020 , camera structure 1021, etc. It should be noted that each component module of the mechanical unit 101 can be one or more, which can be set according to specific conditions. For example, there can be four legs 1015, and each leg 1015 can be equipped with three motors 1012, corresponding There are twelve motors 1012 .

The communication unit 102 can be used for receiving and sending signals, and can also communicate with the network and other devices, for example, after receiving the command information sent by the remote controller or other multi-legged robot 100 to move in a specific direction at a specific speed value according to a specific gait , transmitted to the control unit 110 for processing. The communication unit 102 includes, for example, a WiFi module, a 4G module, a 5G module, a Bluetooth module, an infrared module, and the like.

The sensing unit 103 is used to acquire information data of the surrounding environment of the multi-legged robot 100 and monitor parameter data of various components inside the multi-legged robot 100 , and send them to the control unit 110 . The sensing unit 103 includes a variety of sensors, such as sensors for acquiring surrounding environment information: laser radar (for long-range object detection, distance determination and/or speed value determination), millimeter-wave radar (for short-range object detection, distance determination and/or or speed value), camera, infrared camera, Global Navigation Satellite System (GNSS, Global Navigation Satellite System), etc. Sensors such as monitoring the various parts inside the multi-legged robot 100: inertial measurement unit (IMU, Inertial Measurement Unit) (for measuring the value of velocity value, acceleration value and angular velocity value), plantar sensor (for monitoring the position of plantar force point , foot posture, ground contact force size and direction), temperature sensor (used to detect component temperature). As for other sensors such as load sensors, touch sensors, motor angle sensors, and torque sensors that can be configured on the multi-legged robot 100 , details will not be repeated here.

Interface unit 104 may be used to receive input (e.g., data information, power, etc.) For example, data information, power, etc.). The interface unit 104 may include a power port, a data port such as a USB port, a memory card port, a port for connecting a device with an identification module, an audio input/output (I/O) port, a video I/O port, and the like.

The storage unit 105 is used to store software programs and various data. The storage unit 105 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system program, a motion control program, an application program (such as a text editor), etc.; The data generated in (such as various sensing data acquired by the sensing unit 103, log file data) and the like. In addition, the storage unit 105 may include a high-speed random access memory, and may also include a non-volatile memory, such as a magnetic disk memory, a flash memory, or other volatile solid-state memory.

The display unit 106 is used to display information input by the user or information provided to the user. The display unit 106 may include a display panel 1061, and the display panel 1061 may be configured in the form of a liquid crystal display (Liquid Crystal Display, LCD), an organic light-emitting diode (Organic Light-Emitting Diode, OLED), or the like.

The input unit 107 can be used to receive input numeric or character information. Specifically, the input unit 107 may include a touch panel 1071 and other input devices 1072 . The touch panel 1071, also referred to as a touch screen, can collect user's touch operations (such as the user's operation on the touch panel 1071 or near the touch panel 1071 with the palm, fingers or suitable accessories), and The program drives the corresponding connected device. The touch panel 1071 may include two parts, a touch detection device 1073 and a touch controller 1074 . Among them, the touch detection device 1073 detects the user's touch orientation, detects the signal brought by the touch operation, and transmits the signal to the touch controller 1074; the touch controller 1074 receives the touch information from the touch detection device 1073, and converts it into a touch signal. The point coordinates are sent to the control unit 110, and the commands sent by the control unit 110 can be received and executed. In addition to the touch panel 1071 , the input unit 107 may also include other input devices 1072 . Specifically, other input devices 1072 may include, but are not limited to, one or more of remote control handles, etc., which are not specifically limited here.

Further, the touch panel 1071 can cover the display panel 1061, and when the touch panel 1071 detects a touch operation on or near it, it sends it to the control unit 110 to determine the type of the touch event, and then the control unit 110 according to the touch event The type provides a corresponding visual output on the display panel 1061 . Although in FIG. 1-a, the touch panel 1071 and the display panel 1061 are used as two independent components to realize the input and output functions respectively, but in some embodiments, the touch panel 1071 and the display panel 1061 can be integrated. The implementation of the input and output functions is not specifically limited here.

The control unit 110 is the control center of the multi-legged robot 100. It uses various interfaces and lines to connect the various parts of the whole multi-legged robot 100, and runs or executes the software program stored in the storage unit 105, and calls the software program stored in the storage unit 105. data, so as to control the multi-legged robot 100 as a whole.

The power supply 111 is used to supply power to various components. The power supply 111 may include a battery and a power control board. The power control board is used to control functions such as battery charging, discharging, and power consumption management. In the embodiment shown in Fig. 1-a, the power supply 111 is electrically connected to the control unit 110. sexual connection. It should be noted that each component may be connected to different power sources 111 , or powered by the same power source 111 .

On the basis of the above embodiments, specifically, in some embodiments, the terminal device can be used to communicate with the multi-legged robot 100, and when the terminal device communicates with the multi-legged robot 100, the terminal device can be used to communicate with The multi-legged robot 100 sends instruction information, and the multi-legged robot 100 can receive the instruction information through the communication unit 102, and can transmit the instruction information to the control unit 110 when receiving the instruction information, so that the control unit 110 can be based on the instruction information. Process to get the target speed value. Terminal devices include, but are not limited to: mobile phones, tablet computers, servers, personal computers, wearable smart devices, and other electrical equipment with image capture functions.

The instruction information can be determined according to preset conditions. In one embodiment, the multi-legged robot 100 may include a sensing unit 103, and the sensing unit 103 may generate instruction information according to the current environment where the multi-legged robot 100 is located. The control unit 110 can determine whether the current speed value of the multi-legged robot 100 satisfies a corresponding preset condition according to the instruction information. If satisfied, the current velocity value and current gait movement of the multi-legged robot 100 will be maintained; if not satisfied, the target velocity value and the corresponding target gait will be determined according to the corresponding preset conditions, so that the multi-legged robot can be controlled 100 moves at a target velocity value and corresponding target gait. Environmental sensors may include temperature sensors, air pressure sensors, visual sensors, sound sensors. The instruction information may include temperature information, air pressure information, image information, and sound information. The communication mode between the environment sensor and the control unit 110 may be wired communication or wireless communication. Ways of wireless communication include but are not limited to: wireless network, mobile communication network (3G, 4G, 5G, etc.), Bluetooth, and infrared.

The hardware structure and mechanical structure of the legged robot provided by the present application are described above, and the method of foot end trajectory planning of the legged robot provided by the present application will be described below.

This application provides a method and device for foot trajectory planning of a legged robot and a legged robot, which are used to enable the robot to smoothly go up and down steps and cross obstacles, reduce bumps, and improve the robot's ability to move up and down steps and cross obstacles. stability. The legged robot in this application may be a robot with two legs, three legs, four legs, six legs, eight legs, etc., which is not limited in detail. For the convenience of description, they are collectively referred to as legged robots or robots hereinafter. The coordinates of the foot end position in this application may be the coordinates of the center point of the foot end, or the coordinates of any point on the surface of the foot end, or the coordinates of the foot end touching the ground, which is not limited here.

In this application, different trajectory traction points need to be designed for different obstacle types. For the convenience of description, this application divides the obstacle types into three types of descriptions: one is the scene where the robot goes up the steps; the other is the scene where the robot goes down the steps; It is the scene where the robot crosses obstacles, which will be described separately below.

1. The scene where the robot goes up the stairs:

Please refer to Fig. 2-a, Fig. 2-a is an embodiment of the method for foot trajectory planning of the legged robot provided by the present application. This embodiment corresponds to the scene where the robot goes up the steps. The method includes:

201. Determine the swing height and swing length of the foot end of at least one leg in the first swing phase from lifting from the first step to falling to the second step. The first step is where the foot end of the supporting leg is in the first support phase step, the first support phase and the first swing phase are continuous in time, and the first support phase is earlier than the first swing phase;

The walking cycle of a legged robot refers to the time elapsed from when the foot end of a certain leg touches the ground to when the foot end heel touches the ground again. The foot end trajectory in a single walking cycle mainly includes two stages. One stage is The time period when the foot end is in contact with the ground to generate force, this stage is called the support phase or support phase, which refers to the continuous phase change process of the leg during the period from when the foot end of a single leg touches the ground to when the foot end of the leg is lifted off the ground again; the other stage is The time period during which the foot end swings in the air, which is called the swing phase or swing phase, refers to the continuous phase change process of the leg during the period from when the foot end leaves the ground when the leg is lifted, to when the foot end lands on the ground after the leg is stepped. During the walking process of the robot, the gait of each leg switches back and forth between the stance phase and the swing phase.

In this embodiment, during the process of the robot going up and down the steps, the control unit determines the swing height and swing length of the foot end of at least one supporting leg of the robot from lifting from the first step to falling to the second step. The foot end is lifted from the first step, and after the first swing phase, it lands on the second step. The first step is the step where the foot end is in the first support phase. The first step leaves, the step where the foot end falls again after the first swing phase. The swing height depends on the height difference between the first step and the second step in the vertical direction, and the swing length depends on the horizontal distance from the starting point of the support leg on the first step to the foothold point on the second step .

In some specific embodiments, the swing height and swing length can be determined by the coordinates of the starting point of the foot end and the coordinates of the foothold point, wherein the coordinates of the starting point are the coordinates when the foot end is on the first step, and the coordinates of the foothold point are are the coordinates of the foot end at the second step. The swing height is the coordinate difference between the starting point and the foothold point in the vertical direction, which depends on the height difference between the first step and the second step in the vertical direction, and the swing length is the coordinate difference between the starting point and the foothold point in the horizontal direction. The difference in coordinates, related to the tread widths of the first and second steps.

It should be noted that the steps in this application include single-level, multi-level steps and house stairs, which are not specifically limited. For the convenience of description, they are collectively referred to as steps. The kicking surface in this application refers to the vertical surface of the steps, and the tread refers to the steps level.

202. If the tread surface of the second step is higher than the tread surface of the first step, then determine the first series of track traction points corresponding to the foot end according to the swing height and swing length;

If the tread of the second step is higher than the tread of the first step, it specifically means that the tread of the second step is higher than the tread of the first step in the vertical direction, corresponding to the scene where the robot goes up the steps. The distance between the foot end and the second step is relatively short, and the foot end is easy to hit the vertical kick surface of the second step when it is lifted, and the foot end is easy to hit the edge of the second step during the forward swing process, which will cause the robot to become unstable. , or even fall.

In order to avoid collision between the foot end and the second step during the step-up process, the control unit determines the first series of trajectory traction points of the foot end of the support leg according to the swing height and swing length of the above-mentioned support leg, wherein the first series of trajectory traction points include: At least 1 first foot-end retraction traction point and at least 1 first foot-end-swing forward traction point, the first foot-end retraction traction point is used to pull the foot-end retraction during the lifting process of the foot-end to prevent The end of the foot hits the riser of the second step during lift; the first end-of-foot traction point is used to pull the end of the foot forward and around the first step after the end of the foot is raised above the tread of the second step The edge of the second step.

Furthermore, since the control performance of different legged robots is quite different, the execution ability of the planned foot trajectory is also different. In order for most robots to execute the planned trajectory, the trajectory speed, Acceleration characteristics are softer. Based on the above reasons, in some specific embodiments, the first series of trajectory traction points may further include: at least one first foot-end speed traction point, the first foot-end speed traction point is used for When the distance between the treads of the second step is less than the preset distance, the traction foot reduces the speed and/or acceleration of the tread on the second step, reducing the impact of the foot when it lands, so as to ensure that the foot is stable enough when it lands.

203. Generate a first foot end trajectory according to the first series of trajectory traction points, and control the foot end to land on the second step according to the first foot end trajectory.

The control unit generates the first foot end trajectory according to the first series of trajectory traction points corresponding to the scene of going up stairs, that is, at least one first foot end retraction traction point and at least one first foot end forward swing traction point, which needs to be explained What is more interesting is that the track traction points in this application only play a role of traction on the foot track, and the actual track of the foot end does not necessarily pass through these track traction points. The purpose of these track traction points is to change the track. The first foot end trajectory generated by the first series of trajectory traction points can make the foot end bypass the step (second step) during the lifting process, and prevent the robot from kicking or bumping into the vertical plane of the step when going up the step And the edge of the step, so that the robot can smoothly complete the action of going up the step.

Please refer to Figure 2-b for details. Figure 2-b is a schematic diagram of the first series of trajectory traction points and the first foot end trajectory corresponding to the scene where the robot goes up the steps, where c1 (x1, y1) is the starting point and is located on the first step;

c2(x1-0.1*L, y1+0.3*h) and c3(x1-0.2*L, y1+1.1*h) correspond to the traction point of the first foot end in this embodiment, and its purpose is to make the foot end There is a backward displacement in the x direction, and the foot end is pulled back during the lifting process to avoid touching the kicking surface of the second step during the lifting process of the foot end;

c4(x1, y1+1.2*h) corresponds to the traction point of the first foot end forward swing in this embodiment, and is used to draw the foot end forward swing and bypass the second step after the height of the foot end exceeds the tread height of the second step. the edge of the step, making sure that the end of the foot does not touch the edge of the second step when swinging forward;

c5(x1+L,y1+h) is the foothold, located on the second step, and has a certain safety distance from the edge of the second step;

The foot-end speed traction point is specifically to reduce the foot-end landing speed by setting 1 to 3 speed traction points near the foothold point of the trajectory or at the overlap of the foothold points. Take setting two speed traction points as an example: add two control points c5_2 and c5_3 near or at the overlap of c5, so that the speed and acceleration when the foot reaches the foothold point can be close to or reduced to 0, so that In the process of going up the steps, the end of the foot can smoothly land on the second step, so that the robot can control and track the entire trajectory more smoothly.

In some specific embodiments, before determining the traction points of the first series of trajectories, the control unit may first judge whether there is an intersection between the original foot end trajectory and the riser or tread of the second step: when it is determined that there is no intersection, then the foot There will be no collision between the foot end and the second step, and there is no need to intervene at this time; when it is determined that there is an intersection, the foot end may collide with the second step, and it is necessary to intervene on the original foot end trajectory of the robot, that is, through the above steps 202 and 203 determine the first series of trajectory traction points corresponding to the foot end, and generate the first foot end trajectory according to the first series of trajectory traction points.

In some other specific embodiments, since in the stair climbing scene, if the starting point is relatively close to the riser of the second step, the foot end is likely to collide with the second step during the lifting process, so when determining Before the first series of trajectory traction points, the control unit can first judge whether the distance between the foot end and the rising surface of the second step is less than the preset distance: when it is not less than the preset distance, you can choose not to intervene at this time; when it is less than the preset distance distance, the foot end is likely to collide with the second step. At this time, it is necessary to intervene on the original foot end trajectory of the robot, that is, determine the first series of trajectory traction points corresponding to the foot end through the above steps 202 and 203, and A series of trajectory traction points generate a first foot end trajectory.

2. The scene where the robot goes down the stairs:

Please refer to Fig. 3-a, Fig. 3-a is another embodiment of the method for foot trajectory planning of a legged robot provided by the present application. This embodiment corresponds to the scene where the robot descends steps. The method includes:

301. Determine the swing height and swing length of the foot end of at least one leg in the first swing phase from lifting from the first step to falling to the second step. The first step is where the foot end of the supporting leg is in the first support phase step, the first support phase and the first swing phase are continuous in time, and the first support phase is earlier than the first swing phase;

In this embodiment, step 301 is similar to step 201 in the foregoing embodiment, and will not be repeated here.

302. If the tread of the second step is lower than the tread of the first step, determine the traction points of the second series of tracks corresponding to the foot end according to the swing height and swing length;

If the tread of the second step is lower than the tread of the first step, it specifically means that the height of the tread of the second step in the vertical direction is lower than that of the first step. It is easy to hit the edge of the first step when the end falls, and if the end of the foot steps on the edge of the second step after falling, it may cause the robot to lose stability or even fall.

In order to prevent the foot end from colliding with the first step during the step-down process, and to prevent the foot end from stepping on the edge of the second step when it falls, the control unit determines the second series of the foot end of the support leg according to the swing height and swing length of the above-mentioned support leg. Trajectory pull point. The second series of trajectory traction points include: at least one second traction point for the forward swing of the foot end and at least one second traction point for the retraction of the second foot end; the second traction point for the forward swing of the foot end is used for lifting the foot end The middle traction foot end swings forward and bypasses the edge of the first step; the second foot end retraction traction point is used to pull the foot end back during the fall of the foot end to prevent the foot end from touching the second step during the fall the edge of.

Furthermore, since the control performance of different legged robots is quite different, the execution ability of the planned foot trajectory is also different. In order for most robots to execute the planned trajectory, the trajectory speed, Acceleration characteristics are softer. Based on the above reasons, in some specific embodiments, similar to the foot-end speed traction points in the first series of trajectory traction points, the second series of trajectory traction points may further include: at least one second foot-end speed traction point , the second foot end speed traction point is used to pull the foot end to reduce the speed and/or acceleration of the tread on the second step when the distance between the foot end and the tread surface of the second step is less than a preset distance, so as to reduce the speed and/or acceleration of the foot end The impact force when landing, so as to ensure that the foot is stable enough when landing.

303. Generate a second foot end trajectory according to the second series of trajectory traction points, and control the foot end to land on the second step according to the second foot end trajectory.

The control unit generates the second foot end trajectory according to the second series of trajectory traction points corresponding to the scene of going up stairs, that is, at least one second foot end forward swing traction point and at least one second foot end retraction traction point, which needs to be explained What is more interesting is that the track traction points in this application only play a role of traction on the foot track, and the actual track of the foot end does not necessarily pass through these track traction points. The purpose of these track traction points is to change the track. The second foot end trajectory generated by the second series of trajectory traction points can make the foot end avoid the edge of the step (first step) during the falling process, and prevent the robot from kicking or bumping into the edge of the first step when going down the step. and ensure that the landing point has a certain safety distance from the edge of the second step, so that the robot can smoothly complete the step-down action.

In some specific embodiments, before determining the traction points of the second series of trajectories, the control unit may first judge whether there is an intersection between the original foot end trajectory and the riser or tread of the first step: when it is determined that there is no intersection, then the foot There will be no collision between the foot end and the first step, and no intervention is required at this time; when it is determined that there is an intersection, the foot end may collide with the first step, and it is necessary to intervene on the original foot end trajectory of the robot, that is, through the above steps Steps 302 and 303 determine a second series of trajectory traction points corresponding to the foot end, and generate a second foot end trajectory according to the second series of trajectory traction points.

For details, please refer to Figure 3-b. Figure 3-b is a schematic diagram of the second series of trajectory traction points and the second foot end trajectory corresponding to the scene where the robot descends steps, where c1 (x1, y1) is the starting point and is located on the first step;

c2(x1+1.0*L, y1+0.2*h) and c3(x1+1.2*L, y1+0.1*h) correspond to the traction point of the second foot end forward swing in this embodiment, which are used to lift the foot end During the lifting process, pull the foot to swing forward and avoid the edge of the first step, so as to ensure that the foot will not touch the edge of the first step during the forward swing;

c4(x1+1.1*L, y1-0.7*h) corresponds to the second foot end retraction traction point in this embodiment, which is used to pull the foot end back during the fall of the foot end to ensure that the foot end does not fall. step on the edge of the second step;

c5(x1+L, y1-h) is the foothold, which is located on the second step and has a certain safety distance from the edge of the second step.

The speed traction point at the foot end is specifically set by setting 1 to 3 speed traction points near the foothold point of the trajectory or at the overlapping place of the foothold point. Take setting two speed traction points as an example: add two control points c5_2 and c5_3 near or at the overlap of c5, so that the speed and acceleration when the foot reaches the foothold point can be close to or reduced to 0, so that In the process of going down the steps, the end of the foot can smoothly land on the second step, so that the robot can control and track the entire trajectory more smoothly.

In some specific embodiments, for determining that the foot end of at least one leg is in the first swing phase in step 201 and step 301, the swing height and swing length from the first step to the second step can be divided into two Cases discussed:

1) If the robot is in the blind climbing mode, receive an instruction to filter the target stair size information in the preset stair size table, and determine that the foot end of at least one leg is in the first swing phase and lift from the first step according to the target stair size information. The swing height and swing length to fall to the second step;

The blind climbing mode specifically means that the robot can go up and down stairs without using sensor technology and visual information. Therefore, corresponding to the above-mentioned blind climbing mode, this application also proposes an adaptive judgment method for the up and down steps in the blind climbing model of the robot: by calculating the pitch angle between the robot support leg plane and the ground horizontal plane to judge the robot's current Whether it is an up-step scene or a down-step scene. When the pitch angle pitch between the support leg plane and the horizontal plane is greater than the preset angle θ (for example, 15°), it is judged as a step-up scene. At this time, the robot receives the step-up instruction and adopts the step-up strategy corresponding to the embodiment in Figure 2-a. If the pitch angle pitch is less than -preset angle θ (eg -15°), it is judged as a step-down scene. At this time, the robot receives the step-down command and adopts the step-down strategy corresponding to the embodiment in Fig. 3-a.

Specifically, take the trot double-leg support gait of a quadruped robot as an example. During the movement, the front and rear legs are always in contact with the ground. The control unit obtains the front support leg plane foot_front(x1,y1,z1), and the rear support leg plane foot_hind( x2, y2, z2), the simplified method of pitch angle pithch is as follows:

In this blind climbing mode, it is difficult for the robot to cope with the obstacles caused by the randomness of the foot position in the process of going up and down the steps. However, for some standard steps, especially the stairs in conventional buildings, the inclination angle of such stairs , step height and step width are based on the standard size under the building code, the preset stair size table stores the relationship between the standard stair inclination angle, step height and step width, so the robot can calculate the pitch angle according to the above, Determine the standard stair inclination angle similar to it, and then filter the corresponding target stair size information in the preset stair size table according to the standard stair inclination angle, and then determine the foot end according to the target stair size information (step height and step width). The swing height and swing length are used to realize the up and down steps in the blind climbing mode, and the foot track is pulled through the first series of trajectory traction points and the second series of trajectory traction points, so that the robot can move up and down even in the blind climbing mode. Go up and down steps smoothly.

2) If the robot is in visual mode, determine the swing height and swing length of the foot end of at least one leg in the first swing phase from lifting from the first step to falling to the second step according to the visual information of the robot.

The visual mode of the robot specifically means that the robot can obtain visual information through sensing devices such as cameras, lasers or infrared sensors mounted on the body. If the robot is in the visual mode, the control unit can directly obtain visual information based on the relevant sensing devices Information to determine the step height and step width, so as to plan the foot end trajectory, and obtain the coordinates of the starting point and the foothold point of the foot end of at least one leg in the first swing phase, and then according to the coordinates of the starting point and the foothold Point coordinates determine the swing height and swing length of the foot end, wherein the swing height is the coordinate difference between the starting point and the foothold point in the vertical direction, and the swing length is the coordinate difference between the starting point and the foothold point in the horizontal direction.

3. The scene where the robot crosses obstacles:

Please refer to Fig. 4-a, Fig. 4-a is another embodiment of the method for foot trajectory planning of a legged robot provided by the present application. This embodiment corresponds to the scene where the robot crosses obstacles. The method includes:

401. When an obstacle is sensed, determine attribute information of the obstacle, where the attribute information includes shape and size information;

When the sensor unit of the robot senses an obstacle, the obstacle in this application specifically refers to an obstacle that the robot can cross, such as a threshold, a stone, and other obstacles, and the control unit determines the obstacle according to the sensing information of the sensor unit. The attribute information of the obstacle includes the shape and size information of the obstacle. For example, the control unit determines the shape and size information of the obstacle according to the robot's visual information (ultrasonic, infrared, laser, etc.).

402. Judging whether the preset track switching condition is satisfied according to the attribute information, and if so, execute step 403;

The control unit judges whether the preset trajectory switching conditions are met according to the attribute information of the obstacle. The purpose is to determine whether the robot may collide when crossing the obstacle according to the original foot trajectory. If there is a possibility of collision, it is determined to meet the preset The track switching condition.

In some specific embodiments, the preset track switching condition may be that there is an intersection between the original foot track and the obstacle, that is, the control unit judges whether there is an intersection between the original foot track and the obstacle according to the attribute information of the obstacle, and if not If there is an intersection, control is performed according to the original foot-end trajectory; if there is an intersection, it is determined that the preset trajectory switching condition is met, and step 403 is continued. This is because if there is an intersection between the original foot trajectory and the obstacle, the robot will inevitably collide with the obstacle when swinging its legs across the obstacle. Therefore, it is necessary to perform subsequent steps to intervene on the original foot trajectory to ensure that the robot Able to move smoothly over obstacles.

In some other specific embodiments, the preset trajectory switching condition can also be that the distance between the starting point of the original foot end trajectory and the obstacle is less than the preset distance, that is, the control unit judges the original foot end according to the attribute information of the obstacle. Whether the distance between the starting point and the obstacle in the trajectory is less than the preset distance, if it is greater than or equal to the preset distance, then control according to the original foot end trajectory; if it is less than the preset distance, then determine that the preset trajectory switching condition is met, and continue Execute step 403 . This is because if the starting point of the original foot trajectory is close to the obstacle, it is very likely that the robot will collide with the obstacle during the leg lifting process. Therefore, it is necessary to perform subsequent steps to intervene on the original foot trajectory to ensure that the robot Able to move smoothly over obstacles.

403. Determine the swing height and length of the foot end of at least one leg in the second swing phase from the starting point to the foot landing point according to the attribute information. The starting point is the position where the foot end of the supporting leg is in the second support phase. The two support phases and the second swing phase are continuous in time, and the second support phase is earlier than the second swing phase;

The walking cycle of a legged robot refers to the time elapsed from when the foot end of a certain leg lands on the ground to when the foot end heel touches the ground again. The foot end trajectory in a single walking cycle mainly includes two stages. One stage is The time period when the foot end is in contact with the ground to generate force, this stage is called the support phase or support phase, which refers to the continuous phase change process of the leg during the period from when the foot end of a single leg touches the ground to when the foot end of the leg is lifted off the ground again; the other stage is The time period during which the foot end swings in the air, this stage is called the swing phase or swing phase, refers to the continuous phase change process of the leg during the period from when the foot end leaves the ground when the leg is lifted, to when the foot end falls to the ground after the leg is stepped. During the walking process of the robot, the gait of each leg switches back and forth between the stance phase and the swing phase.

When the control unit determines that the preset trajectory switching condition is satisfied, the foot end of at least one leg is obtained from the swing height and the swing length from the starting point to the foothold point in the second swing phase according to the attribute information of the obstacle. The starting point is raised, and after the second swing phase, the obstacle is crossed and then dropped at the footing point. The swing height and swing length can be determined according to the coordinates of the starting point and the foothold point, where the coordinates of the starting point are the coordinates before the foot end crosses the obstacle, and the coordinates of the foothold point are the coordinates after the foot end crosses the obstacle , the swing height is the coordinate difference between the starting point and the foothold point in the vertical direction, which is related to the height of the obstacle, and the swing length is the coordinate difference between the starting point and the foothold point in the horizontal direction, which is related to the width of the obstacle.

404. Determine the third series of trajectory traction points corresponding to the foot end according to the swing height and swing length;

The control unit determines a third series of trajectory traction points of the foot end of the supporting leg according to the determined swing height and swing length, and the third series of trajectory traction points correspond to a scene where the robot crosses obstacles.

There are two types of traction points in the third series of tracks, the first combination traction point and the second combination traction point, wherein the first combination traction point includes: at least one traction point with the third foot end raised and retracted, at least one first combination traction point The traction point of the front swing of the three-foot end and at least one traction point of the third foot end falling and retracting; the second combined traction point includes at least one traction point of the third foot end lifting and retracting point and at least one third foot end swinging forward Traction point; the difference between the second combination traction point and the first combination traction point is that there is no third foot end retraction traction point, because if there is enough space in front of the foot end when the foot end is dropped, there is no need to retract the foot end when it is dropped , you can select the second combined pull point.

The third foot end lifts and retracts the traction point for pulling the foot end and retracting it in the process of lifting the foot end to prevent the foot end from running into obstacles during the lifting process; After the height of the foot end is lifted beyond the obstacle, the foot end is pulled forward to swing forward and around the edge of the obstacle; the third foot end is retracted after the fall of the third foot end, which is used to pull the foot end to retract during the fall of the foot end to avoid The end of the foot hits the edge of the obstacle during the fall.

Furthermore, since the control performance of different legged robots is quite different, the execution ability of the planned foot trajectory is also different. In order for most robots to execute the planned trajectory, the trajectory speed, Acceleration characteristics are softer. Based on the above reasons, in some specific embodiments, the third series of track traction points may further include: at least one third foot-end speed traction point, the third foot-end speed traction point is used to connect the foot end with the ground When the distance is less than the preset distance, the traction foot end reduces the speed and/or acceleration of the foot landing on the ground, and reduces the impact force when the foot end lands, so as to ensure that the foot end is sufficiently stable when landing.

405 . Generate a third foot end trajectory according to the third series of trajectory traction points, and control the foot end to cross the obstacle according to the third foot end trajectory.

The control unit is based on the third series of trajectory traction points corresponding to the obstacle crossing scene, that is, at least one third foot end lifts and retracts traction point, at least one third foot end swings forward traction point, and at least one third foot end To generate the third foot-end trajectory, or at least 1 third foot-end lift-back traction point and at least 1 third foot-end forward swing traction point to generate the third foot-end trajectory. What is more interesting is that the track traction points in this application only play a role of traction on the foot track, and the actual track of the foot end does not necessarily pass through these track traction points. The purpose of these track traction points is to change the track. The third foot end trajectory generated by the third series of trajectory traction points can prevent the foot end from colliding with the obstacle in the process of crossing the obstacle, so that the robot can smoothly complete the action of crossing the obstacle.

Please refer to Figure 4-b for details. Figure 4-b is a schematic diagram of the third series of trajectory traction points and the third foot end trajectory corresponding to the robot crossing the obstacle scene, where c1 (x1, y1) is the starting point;

c2(x1-0.1*L, y1+0.3*h) and c3(x1-0.2*L, y1+1.1*h) correspond to the traction point after the third foot end is lifted in this embodiment, the purpose is to make the foot During the lifting process, the foot end has a backward displacement in the x direction to ensure that the foot end is retracted to avoid encountering obstacles during the foot end lifting process;

c4(x1, y1+1.2*h), c5(x1+1*L, y1+1.2*h) and c6(x1+1.2*L, y1+1.1*h) correspond to the third foot end in this embodiment The forward swing traction point is used to pull the forward swing of the foot and bypass the edge of the obstacle during the lifting of the foot, so as to ensure that the edge of the obstacle will not be touched during the forward swing of the foot;

c7(x1+1.1*L, y1+0.3*h) corresponds to the traction point after the third foot end falls in this embodiment, and the purpose is to ensure that the foot end does not collide with the edge of the obstacle during the falling process;

c8(x1+L,y1) is the foothold.

The speed traction point at the foot end is specifically set by setting 1 to 3 speed traction points near the foothold point of the trajectory or at the overlapping place of the foothold point. Take setting two speed traction points as an example: add two control points c8_2 and c8_3 near c8 or at the coincident place, so that the speed and acceleration when the foot reaches the foothold point can be close to or reduced to 0, so that After the foot end crosses the obstacle, it can land smoothly, which makes the robot's control and tracking of the entire trajectory more stable.

都是基于摆腿相位

信息所参数化描述的：It should be noted that the first foot end trajectory, the second foot end trajectory and the third foot end trajectory in this application

It's all based on leg swing phase

Information parametrically described by:

是n阶贝塞尔多项式；具有n+1个轨迹牵引点；C_k是第k轨迹牵引点点，其中k∈{0,...8}。在摆腿的垂直平面内，以向前为x轴，向上或向下为y轴建立摆腿规划平面，摆腿面临的台阶信息或障碍物信息来设计轨迹牵引点，以牵引足端轨迹应对障碍物。对于不同的上、下台阶以及跨越障碍物场景，设计可变数量的轨迹牵引点，再基于设计的轨迹牵引点生成机器人的贝塞尔摆腿曲线，即本申请中的第一足端轨迹、第二足端轨迹以及第三足端轨迹，使机器人能够平稳地上下台阶以及跨越障碍物，减少磕碰，提高机器人在上下台阶以及跨越障碍物过程中的稳定性。in

is an n-order Bessel polynomial; there are n+1 trajectory traction points; C _k is the kth trajectory traction point, where k∈{0,...8}. In the vertical plane of the leg swing, set the forward as the x-axis, and the upward or downward as the y-axis to establish the leg swing planning plane, and design the trajectory traction point based on the step information or obstacle information that the leg swing faces, and use the traction foot trajectory to deal with it. obstacle. For different scenes of going up and down steps and crossing obstacles, design a variable number of trajectory traction points, and then generate the Bezier leg swing curve of the robot based on the designed trajectory traction points, that is, the first foot end trajectory in this application, The second foot end trajectory and the third foot end trajectory enable the robot to smoothly go up and down steps and cross obstacles, reduce bumps, and improve the stability of the robot in the process of going up and down steps and crossing obstacles.

The method for planning the trajectory of the foot end of the legged robot in this application has been described above, and the device for trajectory planning of the foot end of the legged robot provided in this application will be described below.

The present application also provides an embodiment of a device for foot trajectory planning of a legged robot, which includes:

Sensing unit 103 and control unit 110;

The sensing unit 103 is used for:

Determine the swing height and swing length of the foot end of at least one leg in the first swing phase from the first step to the second step, the first step is the step where the foot end of the supporting leg is in the first support phase, The first strut phase and the first swing phase are continuous in time, and the first strut phase is earlier than the first swing phase;

The control unit 110 is used for:

If the tread surface of the second step is higher than the tread surface of the first step, the first series of trajectory traction points corresponding to the foot end are determined according to the swing height and swing length;

Generate a first foot end trajectory according to the first series of trajectory traction points, and control the foot end to fall on the second step according to the first foot end trajectory;

If the tread of the second step is lower than the tread of the first step, then determine the traction points of the second series of tracks corresponding to the foot end according to the swing height and swing length;

A second foot end trajectory is generated according to the second series of trajectory traction points, and the foot end is controlled to land on the second step according to the second foot end trajectory.

In the device of this embodiment, the sensing unit 103 and the control unit 110 are as shown in Figure 1-a, and the functions of each unit correspond to the steps in the method embodiment shown in Figure 2-a and Figure 3-a, which are not described here Let me repeat.

The present application also provides another embodiment of the device for foot trajectory planning of a legged robot, which includes: a sensing unit 103 and a control unit 110;

The sensing unit 103 is used for:

When an obstacle is sensed, attribute information of the obstacle is determined, and the attribute information includes shape and size information;

The control unit 110 is used for:

Judging whether the preset track switching conditions are met according to the attribute information;

The sensing unit 103 is also used for:

When the control unit judges according to the attribute information that the preset trajectory switching condition is satisfied, the foot end of at least one leg is determined according to the attribute information in the second swing phase, the swing height and the swing length from the starting point to the foothold point, the starting point is The foot end of the supporting leg is at the position of the second supporting phase, the second supporting phase and the second swinging phase are continuous in time, and the second supporting phase is earlier than the second swinging phase;

The control unit 110 is also used for:

According to the swing height and swing length, determine the traction points of the third series of tracks corresponding to the foot end;

A third foot end trajectory is generated according to the third series of trajectory traction points, and the foot end is controlled to cross the obstacle according to the third foot end trajectory.

In the device of this embodiment, the sensing unit 103 and the control unit 110 are shown in FIG. 1-a, and the functions of each unit correspond to the steps in the aforementioned method embodiment shown in FIG. 4-a, and will not be repeated here.

This application also provides a legged robot, please refer to Figure 5, Figure 5 is an embodiment of the legged robot provided by this application, the legged robot includes:

Processor 501, memory 502, input and output unit 503, bus 504;

The processor 501 is connected to the memory 502, the input and output unit 503 and the bus 504;

The memory 502 stores a program, and the processor 501 invokes the program to execute any of the above methods for foot trajectory planning of a legged robot.

The present application also relates to a computer-readable storage medium, on which a program is stored, which is characterized in that, when the program is run on the computer, the computer is made to execute the method for planning the foot end trajectory of any legged robot.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), magnetic disk or optical disk, and other media that can store program codes.

Claims (12)

1. A method for foot end trajectory planning of a legged robot, the method comprising:

determining the swing height and the swing length of the foot end of at least one leg, which is lifted from a first step to a second step in a first swing phase, wherein the first step is the step where the foot end of the support leg is located in a first support phase, the first support phase and the first swing phase are continuous in time, and the first support phase is earlier than the first swing phase;

if the tread of the second step is higher than the tread of the first step, determining a first series of track traction points corresponding to the foot end according to the swing height and the swing length;

generating a first foot end track according to the first series of track traction points, and controlling the foot end to fall on the second step according to the first foot end track;

if the tread of the second step is lower than the tread of the first step, determining a second series of track traction points corresponding to the foot end according to the swing height and the swing length;

and generating a second foot end track according to the second series of track traction points, and controlling the foot end to fall on a second step according to the second foot end track.

2. The method of claim 1, wherein the first series of trajectory tow points comprises: at least 1 first foot end backward-retracting traction point and at least 1 first foot end forward-swinging traction point;

the at least 1 first foot end backward-retracting traction point is used for drawing the foot end backward-retracting in the foot end lifting process so as to prevent the foot end from touching the kicking surface of the second step in the lifting process;

the at least 1 first foot end forward swing traction point is used for drawing the foot end forward swing to bypass the edge of the second step after the lifting height of the foot end exceeds the tread height of the second step;

the second series of trajectory traction points comprises: at least 1 second foot end forward swing traction point and at least 1 second foot end backward retraction traction point;

the at least 1 second foot end forward swing traction point is used for drawing the foot end forward swing and winding off the edge of the first step in the foot end lifting process;

and the at least 1 second foot end backward-retracting traction point is used for drawing the foot end backward-retracting in the falling process of the foot end and avoiding the foot end from touching the edge of the second step in the falling process.

3. The method of claim 2, wherein the first series of trajectory traction points further comprises: at least 1 first foot end speed traction point, wherein the at least 1 first foot end speed traction point is used for reducing the speed and/or the acceleration of the traction foot end falling on the tread of the second step when the distance between the foot end and the tread of the second step is smaller than a preset distance;

the second series of trajectory traction points further comprises: and the at least 1 second foot end speed traction point is used for reducing the speed and/or the acceleration of the tread of the second step when the distance between the foot end and the tread of the second step is smaller than the preset distance.

4. The method of claim 2 or 3, wherein prior to said determining a first series of trajectory traction points for said foot end from said swing height and swing length, said method further comprises:

judging whether the original foot end track is crossed with a kick surface or a tread of the second step;

the determining a first series of trajectory traction points corresponding to the foot end according to the swing height and the swing length comprises:

if the intersection exists, determining a first series of track traction points corresponding to the foot end according to the swing height and the swing length;

or the like, or, alternatively,

before the determining a second series of trajectory traction points corresponding to the foot end according to the swing height and the swing length, the method further comprises:

judging whether the original foot end track is crossed with a kick surface or a tread of the first step;

the determining a second series of trajectory traction points corresponding to the foot end according to the swing height and the swing length comprises:

and if the intersection exists, determining a second series of track traction points corresponding to the foot end according to the swing height and the swing length.

5. The method of claim 2 or 3, wherein prior to said determining a first series of trajectory traction points for said foot end from said swing height and swing length, said method further comprises:

judging whether the distance between the foot end and the kick surface of the second step is smaller than a preset distance;

the determining a first series of trajectory traction points corresponding to the foot end according to the swing height and the swing length comprises:

if it is less than the above range, the film is formed, determining a first series of track traction points corresponding to the foot end according to the swing height and the swing length.

6. The method of claim 1, wherein determining the swing height and swing length of the foot end of the at least one leg rising from the first step to falling to the second step in the first swing phase comprises:

if the robot is in a blind climbing mode, receiving an instruction to screen target stair size information in a preset stair size table, determining that the foot end of at least one leg is in a first swing phase according to the target stair size information, and lifting the first leg from a first step to a swing height and a swing length of a second step;

or the like, or, alternatively,

and if the robot is in a visual mode, determining the swing height and the swing length of the foot end of at least one leg in the first swing phase, lifting from the first step to the second step according to the visual information of the robot.

7. A method for foot end trajectory planning of a legged robot, the method comprising:

when an obstacle is sensed, determining attribute information of the obstacle, wherein the attribute information comprises shape and size information;

judging whether a preset track switching condition is met or not according to the attribute information;

if so, determining the foot end of at least one leg in a second swing phase, the swing height and the swing length from a starting point to a foot falling point according to the attribute information, wherein the starting point is the position of the foot end of the support leg in the second support phase, the second support phase and the second swing phase are continuous in time, and the second support phase is earlier than the second swing phase;

determining a third series of track traction points corresponding to the foot end according to the swing height and the swing length;

and generating a third foot end track according to the third series of track traction points, and controlling the foot end to cross the obstacle according to the third foot end track.

8. The method of claim 7, wherein the third series of trajectory tow points comprises a first combined tow point and a second combined tow point;

the first combined traction point comprises at least 1 third foot end lifting rear-retracting traction point, at least 1 third foot end front-swinging traction point and at least 1 third foot end falling rear-retracting traction point;

the second combined traction point comprises at least 1 third foot end lifting rear-retracting traction point and at least 1 third foot end front-swinging traction point;

the at least 1 third foot end drawing point which is drawn back after being lifted is used for drawing the foot end to be drawn back in the foot end lifting process, to prevent the foot end from hitting the obstacle during lifting;

the at least 1 third foot end forward swing traction point is used for drawing the foot end forward swing and winding the edge of the obstacle after the foot end is lifted to a height exceeding the obstacle;

and the at least 1 third foot end is drawn after falling and used for drawing the foot end to retract in the falling process of the foot end so as to avoid the foot end from touching the edge of the obstacle in the falling process.

9. The method according to claim 7 or 8, wherein the determining whether a preset track switching condition is met according to the attribute information comprises:

judging whether the original foot end track is crossed with the barrier or not according to the attribute information, and if so, determining that a preset track switching condition is met;

or the like, or, alternatively,

and judging whether the distance between the starting point in the original foot end track and the obstacle is smaller than a preset distance or not according to the attribute information, and if so, determining that a preset track switching condition is met.

10. An apparatus for foot end trajectory planning for a legged robot, the apparatus comprising: a sensing unit and a control unit;

the sensing unit is used for:

determining the swing height and the swing length of the foot end of at least one leg, which is lifted from a first step to a second step in a first swing phase, wherein the first step is the step where the foot end of the support leg is located in a first support phase, the first support phase and the first swing phase are continuous in time, and the first support phase is earlier than the first swing phase;

the control unit is used for:

if the tread of the second step is higher than that of the first step, determining a first series of track traction points corresponding to the foot end according to the swing height and the swing length;

generating a first foot end track according to the first series of track traction points, and controlling the foot end to fall on the second step according to the first foot end track;

if the tread of the second step is lower than the tread of the first step, determining a second series of track traction points corresponding to the foot end according to the swing height and the swing length;

and generating a second foot end track according to the second series of track traction points, and controlling the foot end to fall on a second step according to the second foot end track.

11. An apparatus for foot end trajectory planning for a legged robot, the apparatus comprising: a sensing unit and a control unit;

the sensing unit is used for:

when an obstacle is sensed, determining attribute information of the obstacle, wherein the attribute information comprises shape and size information;

the control unit is used for:

judging whether a preset track switching condition is met or not according to the attribute information;

the sensing unit is further configured to: when the control unit judges that a preset track switching condition is met according to the attribute information, determining that the foot end of at least one leg is in a second swing phase according to the attribute information, and the swing height and the swing length from a starting point to a foot falling point, wherein the starting point is the position of the foot end of the support leg in the second support phase, the second support phase and the second swing phase are continuous in time, and the second support phase is earlier than the second swing phase;

the control unit is further configured to:

determining a third series of track traction points corresponding to the foot end according to the swing height and the swing length;

and generating a third foot end track according to the third series of track traction points, and controlling the foot end to cross the obstacle according to the third foot end track.

12. A legged robot, characterized in that it comprises:

the device comprises a processor, a memory, an input and output unit and a bus;

the processor is connected with the memory, the input and output unit and the bus;

the memory holds a program that the processor calls to perform the method of any of claims 1 to 6 or claims 7 to 9.

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