Method and system for preventing inclination of robot based on PID (Proportion Integration Differentiation) control

Abstract

The invention provides a PID (Proportion Integration Differentiation) control-based robot anti-tilt method, which is characterized by comprising the following steps of: acquiring the current state information of a robot through a state acquisition unit; determining a control signal based on the state information; and the motion state of the robot is adjusted according to the control signal. By obtaining the current state information of the robot, the actual situation of the robot in the operation process can be known in real time, for example, whether the robot tends to incline or not. A control signal is determined based on the state information, and the motion state of the robot is further adjusted, so that the robot can correct the posture in time, the situation that the robot loses balance, falls down and the like due to abnormal conditions such as inclination is avoided, it is guaranteed that the robot can run stably under various working conditions, and the working efficiency is improved. When working on a flat road surface or an uneven ground with a certain gradient, the stable motion state can be maintained, and the reliability of the whole operation can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and in particular to a robot anti-tilt method and system based on PID control. Background Art

[0002] With the rapid development of robot technology in my country, robots have been widely used in various fields, such as service, logistics, inspection, etc. At present, how to ensure the stable movement of robots in complex outdoor environments has become an important research topic.

[0003] Traditional anti-tilt methods mainly rely on the design of mechanical structures, such as low center of gravity and wide chassis. However, these methods have obvious limitations. First, they mainly rely on the designer's presets and cannot adapt to environmental changes in real time; second, in actual application, these methods may produce some side effects due to the complexity and variability of the environment. Summary of the invention

[0004] The present invention provides a robot anti-tilt method and system based on PID control, which are used to solve the problem that the traditional robot anti-tilt method cannot adapt to the complexity and variability of the environment.

[0005] A robot anti-tilt method based on PID control, comprising:

[0006] Obtain the current status information of the robot through the status acquisition unit;

[0007] determining a control signal based on the state information;

[0008] Adjust the robot's motion state according to the control signal;

[0009] The state information includes one or more combinations of tilt angle, acceleration, load and posture information.

[0010] Furthermore, the calculation formula of the control signal is:

[0011] Where u(t) represents the control signal; e(t) represents the error; K p , K i , K d are proportional, integral and derivative gains respectively;

[0012] K p e(t): This is the proportional control part, which is based on the error e(t) multiplied by the proportional coefficient K p , directly affects the control output.

[0013] K i∫e(t)dt: This is the integral control part, which represents the total amount of accumulated error over a period of time. The integral symbol ∫e(t)dt represents the accumulation of the error e(t) over time t, that is, the sum of the errors in the time period [0, t]. Integral control is used to eliminate steady-state errors and help the system reach the target state after long-term operation.

[0014] This is the derivative control part, which represents the rate of change of the error over time. It represents the derivative of the error with respect to time, that is, the speed of change of the error at a certain moment. Derivative control helps to predict the trend of error change, thereby providing a counteracting effect when the error changes rapidly and preventing the system from oscillating.

[0015] Furthermore, the error calculation formula is: e(t) = θ set -θ current

[0016] Where: θset is the target tilt angle; θcurrent is the current tilt angle.

[0017] Further, determining a control signal based on the state information includes:

[0018] Determine a parameter set from a pre-configured parameter determination library based on acceleration, load and attitude information; parse the parameter set to determine proportional, integral and differential gains.

[0019] Furthermore, it also includes:

[0020] Obtain the robot's driving environment information;

[0021] Comprehensively analyze driving environment information and status information to determine the target tilt angle;

[0022] Among them, obtaining the robot's driving environment information includes:

[0023] The image acquisition device is used to collect ground images within a preset distance range in front of the robot's driving direction;

[0024] and / or,

[0025] The laser radar configured on the robot scans the ground within a preset distance range in the direction of travel of the robot.

[0026] A robot anti-tilt system based on PID control includes: a state acquisition unit, an analysis unit and an execution unit; wherein the state acquisition unit acquires the current state information of the robot; the analysis unit determines a control signal based on the state information; and the execution unit adjusts the motion state of the robot according to the control signal.

[0027] The state information includes: one or more combinations of tilt angle, acceleration, load and posture information;

[0028] The control signal is calculated as:

[0029] Further, the analysis unit determines a control signal based on the state information and performs the following operations:

[0030] Determine a parameter set from a pre-configured parameter determination library based on acceleration, load and attitude information;

[0031] Analyze the parameter set to determine the proportional, integral, and derivative gains.

[0032] Further, it also includes: an adaptation configuration unit;

[0033] The adaptation configuration unit performs the following operations:

[0034] Obtain the robot's driving environment information;

[0035] Comprehensively analyze driving environment information and status information to determine the target tilt angle;

[0036] Among them, obtaining the robot's driving environment information includes:

[0037] The image acquisition device is used to collect ground images within a preset distance range in front of the robot's driving direction;

[0038] and / or,

[0039] The laser radar configured on the robot scans the ground within a preset distance range in the direction of travel of the robot.

[0040] Beneficial effects of the present invention:

[0041] 1. By obtaining the current status information of the robot, the actual situation of the robot during operation can be known in real time, such as whether there is a tilting trend. Based on this status information, the control signal is determined, and the robot's motion state is further adjusted, so that the robot can correct its posture in time to avoid losing balance and falling due to abnormal conditions such as tilting, etc., to ensure that the robot can operate relatively smoothly under various working conditions, whether it is operating on a flat road or on a certain slope or uneven ground, it can maintain a stable motion state, which helps to improve its overall operation reliability.

[0042] 2. Using the PID control mechanism, the control signal can be adjusted dynamically according to different state information. PID control itself has the advantage of accurately adjusting the error. The proportional link can respond quickly according to the current error, the integral link can eliminate the steady-state error of the system, and the differential link responds to the rate of change of the error, predicting and adjusting in advance. This allows the robot to achieve accurate motion state adjustment for complex situations such as different loads, different motion accelerations, and posture changes, better adapt to diverse work scenarios and task requirements, and enhance the robot's ability to complete tasks in different environments.

[0043] 3. Reducing the impact and damage to the robot's mechanical structure, electronic components, etc. caused by abnormal situations such as tilting and falling will help reduce the robot's failure rate and enable the robot's components to operate under relatively stable and reasonable working conditions. In the long run, it can effectively extend the robot's service life and reduce its use and maintenance costs.

[0044] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0045] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0047] Figure 1 This is an example diagram of a robot anti-tilt method based on PID control in an embodiment of the present invention.

[0048] Figure 2 This is an example diagram of a robot anti-tilt system based on PID control in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0050] Example 1

[0051] This application comprehensively upgrades the robot's anti-tilt mechanism for the application of the robot in various complex working conditions, especially in scenarios where there may be a risk of tilting. In terms of the robot structure, various sensors are rationally arranged to achieve all-round monitoring of the robot's status, and tilt sensors, acceleration sensors, attitude sensors, and pressure sensors are set at key locations. Multiple pressure sensors are arrayed on the load-bearing components to accurately sense the robot's load condition.

[0052] In order to achieve real-time mastery and automatic control of the robot's status, a variety of sensor fusion methods are used to monitor the overall status of the robot, especially the use of gyroscopes to accurately track the posture changes of key parts of the robot.

[0053] In terms of balance control, the anti-tilt method based on PID control provided by the present application further deepens the control strategy on the basis of controlling the robot drive mechanism (such as the motor action of the joints on the wheel-leg mechanism) according to the monitoring status. When the robot is in different operating states, differentiated control means are adopted. For example, when unloaded, a specially configured balance control parameter data group corresponding to the unloaded is used for balance control. The balance control parameter data group covers: moving speed control parameters, working power control parameters of the motors of each joint on the wheel-leg mechanism corresponding to each state change, and control parameters of the motor rotation direction corresponding to each state change.

[0054] When the state information such as load, acceleration, posture, etc. changes, in order to better cope with this scenario, the robot anti-tilt method based on PID control provided in this application is as follows: Figure 1 As shown, including:

[0055] Obtain the current status information of the robot through the status acquisition unit;

[0056] determining a control signal based on the state information;

[0057] According to the control signal, the motion state of the robot is adjusted.

[0058] Further, the state information includes: one or more combinations of tilt angle, acceleration, load and posture information;

[0059] Furthermore, the calculation formula of the control signal is:

[0060] Where u(t) is the control output; e(t) is the error between the set value and the current value; K p , K i , K d are proportional, integral and differential gains respectively; K pe(t): This is the proportional control part, which is based on the error e(t) multiplied by the proportional coefficient K p , directly affects the control output; K i ∫e(t)dt: This is the integral control part, which represents the total amount of accumulated error over a period of time. The integral symbol ∫e(t)dt represents the accumulation of error e(t) over time t, that is, the sum of errors in the time period [0, t]. Integral control is used to eliminate steady-state errors and help the system reach the target state after long-term operation; This is the derivative control part, which represents the rate of change of the error over time. It represents the derivative of the error with respect to time, that is, the speed of change of the error at a certain moment. Derivative control helps to predict the trend of error change, thereby providing a counteracting effect when the error changes rapidly and preventing the system from oscillating.

[0061] Furthermore, the error calculation formula is: e(t) = θ set -θ current

[0062] Where: θset is the target tilt angle; θcurrent is the current tilt angle.

[0063] Further, determining a control signal based on the state information includes:

[0064] Determine a parameter set from a pre-configured parameter determination library based on acceleration, load and attitude information;

[0065] Analyze the parameter set to determine the proportional, integral, and derivative gains.

[0066] Among them, the parameter determination library is constructed in advance, and the parameter set and the state information in the parameter determination library are associated one by one; when the parameter determination library is applied, the corresponding parameter set can be directly called out through the state information obtained in the current state, and then the control output is calculated by bringing the parameter set into the calculation formula of the control signal.

[0067] The working principle of the above technical solution is as follows: First, the state acquisition unit collects the current state information of the robot through a variety of sensors. When the robot is in operation, the tilt sensor can detect in real time whether the robot is tilted and the tilt angle, just like our body senses whether it is tilted; the acceleration sensor can sense the speed change of the robot during movement, such as the acceleration during acceleration, deceleration or turning; the load sensor is used to measure the weight carried by the robot to understand its load condition; the posture sensor can determine the posture of the robot in space in all directions, such as whether it is upright, leaning forward or tilting sideways. The tilt angle, acceleration, load and posture information collected by these sensors, alone or in combination, accurately depict the operating state of the robot at this moment, providing basic data for subsequent control decisions.

[0068] Then, based on the collected state information, the control signal generation stage is entered. The present invention uses the PID control algorithm, the core of which is to calculate the control signal based on the error between the current state and the target state. First, the error e(t) is calculated, and the formula e(t) = θ set -θ current The result is the difference between the target tilt angle θset and the current tilt angle θcurrent. This error reflects the deviation between the actual tilt state of the robot and the expected tilt state.

[0069] Next, based on the acceleration, load and posture information, an adapted parameter set is selected from a pre-configured parameter determination library;

[0070] Then, use the calculation formula of PID control signal To determine the control signal u(t).

[0071] After obtaining the control signal u(t), the robot enters the stage of adjusting its motion state. The control signal is like the robot's "action command", which will be transmitted to the robot's actuator. If the control signal indicates that the robot is tilted to the left, the motor will adjust its speed, steering and other parameters according to the requirements of the control signal, and drive the corresponding joints or components of the robot to make actions, such as adjusting the angle of the leg joints, changing the rotation speed or direction of the wheels, etc. Through these actions, the robot can readjust its center of gravity, change its posture, gradually reduce the tilt angle, and finally return to the target tilt angle or maintain it within a stable posture range, thereby realizing the robot's anti-tilt control and ensuring its stable operation under various working conditions.

[0072] The beneficial effects of the above technical solution are:

[0073] 1. With the help of the status acquisition unit, the robot's status information is continuously acquired, and the robot's operating status is monitored in real time. This means that signs of the robot's possible tilt can be discovered as early as possible, rather than waiting until the tilt is serious or even falls over, so that preventive measures can be taken in advance, effectively reducing the risk of the robot losing balance due to accidental tilting, and improving the robot's stability and reliability in daily operation.

[0074] 2. Since the control signal is determined based on the collected multi-dimensional state information, the robot can respond flexibly according to its own different operating conditions. Whether it is due to a sudden increase in load, a change in acceleration caused by walking on an uneven road, or a slight change in its own posture, etc., it can generate appropriate control signals and adjust the motion state in a targeted manner, so that the robot can better adapt to the complex and changeable actual working environment and ensure that it can maintain a stable posture as much as possible under various working conditions.

[0075] 3. Reduce the impact and damage to the robot's mechanical structure and electronic components caused by abnormal situations such as tilting and falling. The robot's components can work under relatively stable and normal stress and operating conditions. In the long run, it helps to reduce the failure rate of the equipment, extend the service life of the robot, and reduce the cost of use and maintenance.

[0076] Example 2

[0077] For the robot anti-tilt method based on PID control in Example 1, according to the state information, the parameter determination library is queried to determine the parameter set. There may be a situation where the obtained parameter set is consistent with the currently used parameter set. In order to deal with this situation, the robot anti-tilt method based on PID control provided in this embodiment provides specific steps for obtaining the parameter set from the parameter determination library, as follows: from the parameter determination library, extract the state information corresponding to the currently used parameter set and match it with the currently obtained state information; when the match is consistent, do not obtain the parameter set; when it is not consistent, match the currently obtained state information with the state information data of the parameter determination library; extract the parameter set associated with the matched state information. That is, first determine whether the currently used is consistent with the determined one, thereby improving the reaction efficiency.

[0078] For the matching of the state information extracted from the parameter determination library and the current state information, the two state information data can be standardized and normalized to obtain a data set, and then the similarity between the two data sets is calculated. When the similarity between the two is less than a preset threshold, it is determined that the match does not match; when the similarity between the two is greater than or equal to the preset threshold, it is determined that the match matches; if the match matches, there is no need to re-acquire the parameter set; when the match does not match, the parameter set is re-acquired.

[0079] The present invention first compares the state information corresponding to the currently used parameter set with the currently obtained state information, and does not re-acquire the parameter set when the two match, thereby avoiding unnecessary repeated queries and data processing. This can greatly reduce the number of visits to the parameter determination library and the consumption of computing resources when the robot is running continuously and the state information changes are not very frequent, so that the system can use more computing resources for other key control links, such as more accurately adjusting the motion state, etc., which improves the overall computing efficiency of the robot's anti-tilt control mechanism and makes the system run more smoothly and efficiently.

[0080] Example 3

[0081] On the basis of Example 2, the robot anti-tilt method based on PID control further includes: acquiring the driving environment information of the robot;

[0082] Comprehensively analyze driving environment information and status information to determine the target tilt angle;

[0083] Among them, obtaining the robot's driving environment information includes:

[0084] The image acquisition device is used to collect ground images within a preset distance range in front of the robot's driving direction;

[0085] and / or,

[0086] The laser radar configured on the robot scans the ground within a preset distance range in the direction of travel of the robot.

[0087] During the actual movement process, the robot uses the image acquisition device to obtain the ground image within a preset distance range in front of it, emits a laser beam through the lidar, and measures the time delay of the reflected light, thereby obtaining the precise three-dimensional coordinate information of the ground within a preset range in front of the robot's travel direction.

[0088] The ground feature information obtained by the image acquisition device and the point cloud data of the LiDAR are fused to build a detailed model of the robot's driving environment. This model not only includes the geometry of the ground, but also evaluates the stability of different areas. For example, areas with steep slopes are marked as high-risk areas, while flat areas are marked as low-risk areas.

[0089] At the same time, the robot's state acquisition unit continuously obtains its own state information, including tilt angle, acceleration, load and posture information.

[0090] According to the pre-set algorithm, the driving environment model and the robot's state information are comprehensively analyzed. On a relatively flat road with a few small bumps, if the robot is slow and has a light load, the algorithm may set the target tilt angle to ≤2° to ensure that the robot can smoothly transition when passing through small bumps, considering the need to maintain an efficient driving speed while avoiding the impact of bumps caused by small bumps on the cargo. When the robot is about to enter a slope area with a slope of 15°, the algorithm will adjust the target tilt angle to 6°-7° based on factors such as the current speed, load, and the length and angle of the slope, so that the robot can climb the slope in the best posture, ensuring that it does not tilt backward and can effectively use power.

[0091] By using image acquisition devices and lidar to obtain all-round driving environment information, the robot can know the road conditions ahead in advance. Whether it is complex terrain such as small bumps, potholes or slopes, the robot can adjust its posture in advance to avoid tilting out of control and always maintain a stable driving posture.

[0092] Example 4

[0093] The present invention also provides a robot anti-tilt system based on PID control, such as Figure 2 As shown, it includes: a state acquisition unit, an analysis unit and an execution unit; wherein the state acquisition unit obtains the current state information of the robot through the state acquisition unit; the analysis unit determines the control signal based on the state information; and the execution unit adjusts the motion state of the robot according to the control signal.

[0094] The state information includes: one or more combinations of tilt angle, acceleration, load and posture information;

[0095] The control signal is calculated as:

[0096] The analysis unit determines the control signal based on the state information and performs the following operations:

[0097] Determine a parameter set from a pre-configured parameter determination library based on acceleration, load and attitude information;

[0098] Analyze the parameter set to determine the proportional, integral, and derivative gains.

[0099] Example 5

[0100] In order to ensure the stability of the robot's operation and its adaptability to complex terrain, on the basis of Example 4, the robot anti-tilt system based on PID control further includes: an adaptation configuration unit;

[0101] The adaptation configuration unit performs the following operations:

[0102] Obtain the robot's driving environment information;

[0103] Comprehensively analyze driving environment information and status information to determine the target tilt angle;

[0104] Among them, obtaining the robot's driving environment information includes:

[0105] The image acquisition device is used to collect ground images within a preset distance range in front of the robot's driving direction;

[0106] and / or,

[0107] The laser radar configured on the robot scans the ground within a preset distance range in the direction of travel of the robot.

[0108] Example 6

[0109] In order to further ensure the stability of the robot's operation and its adaptability to complex terrain, based on Example 5, the robot's limb joints are connected by flexible materials with certain elasticity and damping properties. During the robot's movement, this flexible joint can automatically produce a certain deformation according to the force conditions, playing a role in buffering and adaptive adjustment. When the robot encounters an uneven ground or is impacted by external forces and has a tendency to tilt, the flexible joint can absorb part of the energy through its own deformation, reduce the impact on the overall structure, and buy time for posture adjustment.

[0110] The robot chassis is made of special deformable materials, such as a composite material of shape memory alloy and flexible rubber. The chassis surface is designed with multiple adjustable raised and recessed areas. Under normal conditions, the chassis remains flat to ensure stable support. When the sensor detects that the ground condition is poor or the robot is at risk of tilting, the deformable chassis can quickly change shape according to the command, and by adjusting the position and height of the protrusions and depressions, increase the friction and contact stability with the ground, thereby effectively preventing tilting.

[0111] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A robot anti-tilt method based on PID control, characterized in that: include: Obtain the current status information of the robot through the status acquisition unit; determining a control signal based on the status information; According to the control signal, the motion state of the robot is adjusted.

2. The robot anti-tilt method based on PID control as claimed in claim 1, characterized in that: The status information includes one or more combinations of tilt angle, acceleration, load and posture information.

3. The robot anti-tilt method based on PID control as claimed in claim 1, characterized in that: The calculation formula of the control signal is: Where u(t) represents the control signal; e(t) represents the error; K p , K i , K d are proportional, integral and derivative gains respectively; The error calculation formula is: e(t) = θ set -θ current Where: θset is the target tilt angle; θcurrent is the current tilt angle.

4. The robot anti-tilt method based on PID control as claimed in claim 3, characterized in that: A control signal is determined based on the state information, including: Determine a parameter set from a pre-configured parameter determination library based on acceleration, load and attitude information; Analyze the parameter set to determine the proportional, integral, and derivative gains.

5. The robot anti-tilt method based on PID control as claimed in claim 1, characterized in that: Also includes: Obtain the robot's driving environment information; Comprehensively analyze driving environment information and status information to determine the target tilt angle; Among them, obtaining the robot's driving environment information includes: The image acquisition device is used to collect ground images within a preset distance range in front of the robot's driving direction; and / or, The laser radar configured on the robot scans the ground within a preset distance range in the direction of travel of the robot.

6. A robot anti-tilt system based on PID control, characterized in that: include: A state acquisition unit, an analysis unit and an execution unit; wherein the state acquisition unit acquires the current state information of the robot through the state acquisition unit; The analysis unit determines a control signal based on the state information; the execution unit adjusts the motion state of the robot according to the control signal.

7. The robot anti-tilt system based on PID control as claimed in claim 6, characterized in that: The status information includes one or more combinations of tilt angle, acceleration, load and posture information.

8. The robot anti-tilt system based on PID control as claimed in claim 6, characterized in that: The calculation formula of the control signal is: Where u(t) represents the control signal; e(t) represents the error; K p , K i , K d are proportional, integral and derivative gains respectively; The error calculation formula is: e(t) = θ set -θ current Where: θset is the target tilt angle; θcurrent is the current tilt angle.

9. The robot anti-tilt system based on PID control as claimed in claim 8, characterized in that: The analysis unit determines the control signal based on the status information and performs the following operations: Determine a parameter set from a pre-configured parameter determination library based on acceleration, load and attitude information; Analyze the parameter set to determine the proportional, integral, and derivative gains.

10. The robot anti-tilt system based on PID control according to claim 6, characterized in that: Also includes: Adaptation configuration unit; The adaptation configuration unit performs the following operations: Obtain the robot's driving environment information; Comprehensively analyze driving environment information and status information to determine the target tilt angle; Among them, obtaining the robot's driving environment information includes: The image acquisition device is used to collect ground images within a preset distance range in front of the robot's driving direction; and / or, The laser radar configured on the robot scans the ground within a preset distance range in the direction of travel of the robot.

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