A quadruped robot complex environment low-cost integrated navigation method and system

Abstract

The application provides a kind of quadruped robot complex environment low-cost combination navigation method and system, belong to robot technical field, specifically include: according to the stride of quadruped robot four legs and frequency, velocity fitting function is used to determine the velocity information of quadruped robot, based on the three attitude angles of real-time output of inertial measurement unit installed on quadruped robot, and the motion attitude information of quadruped robot is obtained by the heading error and magnetic declination compensation of attitude angle, the navigation position is calculated using the information of previous time of quadruped robot and the motion attitude information and velocity information of current time, the position information of current time is calculated, based on the position information and the compensation data in the preset time period of current, the attitude control of quadruped robot is carried out, until the positioning information of quality meeting the requirements is obtained, the navigation position is updated in real time, to correct the position error accumulated when navigation position is calculated, ensure the reliability of robot operation control.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, and in particular relates to a low-cost combined navigation method and system for quadruped robots in complex environments. Background Technology

[0002] To achieve navigation control of quadruped robots, existing technologies such as lidar / IMU / GNSS integrated navigation or depth camera / IMU / GNSS integrated navigation can provide high-quality navigation information. However, these technologies suffer from high sensor hardware costs and large computational demands. Furthermore, it is difficult for quadruped robots to achieve autonomous navigation directly based on non-perceptive reinforcement learning motion control, requiring the installation of a high-precision navigation system, which directly increases system cost and complexity.

[0003] To address the aforementioned technical problems, this invention provides a low-cost integrated navigation method and system for quadruped robots in complex environments. Summary of the Invention

[0004] To achieve the objectives of this invention, the following technical solution is adopted:

[0005] According to one aspect of the present invention, a low-cost combined navigation method for quadruped robots in complex environments is provided.

[0006] A low-cost integrated navigation method for quadruped robots in complex environments, characterized by:

[0007] S1 acquires the positioning information of the quadruped robot in real time, and proceeds to the next step when the signal quality of the positioning information does not meet the requirements.

[0008] S2 defines the periods when the signal quality does not meet the requirements as periods of poor signal quality, and when the positioning accuracy of the quadruped robot is determined to be controllable based on the distribution of periods of poor signal quality within the current preset time period of the quadruped robot, proceeds to the next step.

[0009] S3 determines the speed information of the quadruped robot by using a speed fitting function based on the stride and frequency of the quadruped robot's four legs. Based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot, the motion attitude information of the quadruped robot is obtained by compensating for heading error and magnetic declination through the attitude angles.

[0010] S4 uses the information from the previous moment and the motion posture and velocity information of the quadruped robot at the current moment to calculate the navigation position, calculate the position information at the current moment, and perform posture control of the quadruped robot based on the position information and the compensation data within the current preset time period until the positioning information that meets the quality requirements is obtained, and then updates the navigation position in real time.

[0011] A further technical solution is that the positioning information of the quadruped robot is determined based on the quadruped robot's satellite positioning equipment.

[0012] A further technical solution involves determining the signal quality of the positioning information using the following method:

[0013] Based on the location information, the feature quantities of the location data in different signal quality dimensions are determined, and the signal quality of the location information is determined by the weights of the feature quantities in different signal quality dimensions.

[0014] A further technical solution is that when the signal quality of the positioning information meets the requirements, the navigation position is updated based on the positioning information, and navigation management is performed based on the navigation position.

[0015] A further technical solution is that when the compensation amount for either the heading error or the magnetic declination at the specified time is greater than a preset compensation threshold, the specified time is determined to be the error compensation time.

[0016] A further technical solution is that when the change in position between the stated time and the previous time is not within a preset range, the stated time is determined to be a time of abnormal position change.

[0017] A further technical solution involves controlling the posture of the quadruped robot through a preset posture control strategy, specifically including:

[0018] The quadruped robot is controlled to pause its movement until the signal quality of the quadruped robot's positioning information meets the requirements.

[0019] On the other hand, the present invention provides a low-cost integrated navigation system for quadruped robots in complex environments, employing the aforementioned low-cost integrated navigation method for quadruped robots in complex environments, characterized in that it specifically includes:

[0020] Signal quality assessment module, positioning accuracy assessment module, motion attitude acquisition module, navigation processing module;

[0021] The signal quality assessment module is responsible for acquiring the positioning information of the quadruped robot in real time and determining whether the signal quality of the positioning information meets the requirements.

[0022] The positioning accuracy evaluation module is responsible for identifying periods when the signal quality does not meet the requirements as periods of poor signal quality, and determining whether the positioning accuracy of the quadruped robot is controllable based on the distribution of periods of poor signal quality within the current preset time period of the quadruped robot.

[0023] The motion attitude acquisition module is responsible for determining the speed information of the quadruped robot by using a speed fitting function based on the stride and frequency of the quadruped robot's four legs, and obtaining the motion attitude information of the quadruped robot by compensating for heading error and magnetic declination through the attitude angles based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot.

[0024] The navigation processing module is responsible for using the information of the quadruped robot in the previous moment and the motion posture and speed information in the current moment to calculate the navigation position, calculate the position information in the current moment, and perform posture control of the quadruped robot based on the position information and the compensation data in the current preset time period until the positioning information that meets the quality requirements is obtained, and then update the navigation position in real time.

[0025] The beneficial effects of this invention are as follows:

[0026] By fully utilizing the quadrupedal robot's quadrupedal motion characteristics, low-cost satellite positioning equipment, and the quadrupedal robot's built-in inertial measurement unit, a quadrupedal robot navigation system is formed, which can meet the autonomous navigation needs of quadrupedal robots. At the same time, it effectively solves the problems of high cost and system complexity of existing quadrupedal robot navigation systems.

[0027] Other features and advantages will be set forth in the following description, and the objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0029] The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0030] Figure 1 A flowchart of a low-cost integrated navigation method for quadruped robots in complex environments;

[0031] Figure 2 This is a flowchart illustrating the method for determining the positioning accuracy of a quadruped robot;

[0032] Figure 3 This is a flowchart illustrating the method for determining the speed information of a quadruped robot;

[0033] Figure 4 This is a flowchart of a method for determining the posture control of a quadruped robot;

[0034] Figure 5 This is a framework diagram of a low-cost integrated navigation system for quadruped robots in complex environments.

[0035] Figure 6 This is a diagram of the carrier coordinate system for a quadruped robot.

[0036] Figure 7 This is a graph showing the relationship between the navigation position error and time for a quadruped robot. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0038] (a) Existing technologies

[0039] Currently, quadruped robot navigation primarily employs LiDAR or depth cameras, integrating real-time information from the inertial measurement unit (IMU) installed on the quadruped robot for SLAM navigation. For tasks covering a large area, GNSS (Global Navigation Satellite System) equipment is often added for combined navigation. Both LiDAR / IMU / GNSS and depth camera / IMU / GNSS combined navigation can achieve precise real-time positioning of the quadruped robot, transmitting its precise position information to the control terminal for display and monitoring. With the rapid development of quadruped robot motion control technology, motion control is gradually shifting from traditional model control (relying on LiDAR / IMU or depth camera / IMU fusion information) to sensorless reinforcement learning-based motion control. Sensorless reinforcement learning can effectively improve the motion control capabilities of quadruped robots without relying on environmental perception sensors, but it requires the addition of high-precision navigation sensors for autonomous navigation.

[0040] (ii) Deficiencies of existing technologies

[0041] Both lidar / IMU / GNSS integrated navigation and depth camera / IMU / GNSS integrated navigation can provide high-quality navigation information, but they suffer from high sensor hardware costs and large computational loads on the integrated navigation software. Autonomous navigation of quadruped robots based on non-perceptive reinforcement learning motion control is difficult and requires the installation of a high-precision navigation system, which directly increases system cost and complexity. In summary, the shortcomings of existing technologies can be summarized as follows: 1) Existing lidar / IMU / GNSS integrated navigation or depth camera / IMU / GNSS integrated navigation is costly and computationally intensive; 2) Non-perceptive reinforcement learning motion control of quadruped robots requires additional navigation equipment, increasing system cost and complexity.

[0042] This invention relates to a low-cost integrated navigation system for quadruped robots in complex environments. This system achieves autonomous navigation in complex environments by utilizing the quadruped robot's gait, step frequency, inertial measurement unit, and satellite positioning equipment. Specifically, the sensor used in this invention is a WHEELTEC-type GPS / BD dual-mode GNSS positioning module, and the remaining equipment is a biomimetic quadruped robot. This robot includes a YIS320 inertial measurement unit, a customized RK3588 motion control board, and a navigation information processing board. The software deployment environment is Ubuntu 18.04 and ROS Melodic robot operating system. All devices are powered by the quadruped robot's battery pack via a pressure plate conversion board.

[0043] Specifically, a low-cost integrated navigation system for quadruped robots in complex environments is described, with the following implementation steps:

[0044] Step 1: Establish the quadruped robot's carrier coordinate system and navigation coordinate system. Using the quadruped robot's motion control model and external speed measuring equipment, measure and record the quadruped robot's actual movement speed, stride length, and frequency. Use the least squares method to fit the relationship between the quadruped robot's actual movement speed and its stride length and frequency.

[0045] Step 2: Based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot, perform precise error compensation for the installation attitude angle, and perform installation error angle and magnetic declination compensation for the heading angle.

[0046] Step 3: When the quadruped robot is working in a complex environment that prevents the satellite positioning device from outputting positioning information in real time, the navigation position is calculated by using the information of the quadruped robot at the previous moment and the posture and speed information at the current moment.

[0047] Step 4: When the quadruped robot's satellite positioning device can obtain high-quality positioning information, it can update the position calculated in dead reckoning step 3) in real time to correct the position error accumulated during navigation position calculation.

[0048] Step 5: Perform error analysis on the navigation solution model to evaluate the navigation error of the quadruped robot.

[0049] Step 6: Set up and debug the hardware and software environment to ensure that all devices are working properly; develop navigation software based on the above process and navigation calculation principle diagram, and verify the navigation capability on the quadruped robot.

[0050] Example 1

[0051] To solve the above problems, according to one aspect of the present invention, such as Figure 1As shown, a low-cost integrated navigation method for quadruped robots in complex environments is provided, characterized by:

[0052] S1 acquires the positioning information of the quadruped robot in real time, and proceeds to the next step when the signal quality of the positioning information does not meet the requirements.

[0053] Furthermore, the positioning information of the quadruped robot is determined based on the quadruped robot's satellite positioning equipment.

[0054] Specifically, the method for determining the signal quality of the positioning information is as follows:

[0055] Based on the location information, the feature quantities of the location data in different signal quality dimensions are determined, and the signal quality of the location information is determined by the weights of the feature quantities in different signal quality dimensions.

[0056] Furthermore, when the signal quality of the positioning information meets the requirements, the navigation position is updated based on the positioning information, and navigation management is performed based on the navigation position.

[0057] S2 defines the periods when the signal quality does not meet the requirements as periods of poor signal quality, and when the positioning accuracy of the quadruped robot is determined to be controllable based on the distribution of periods of poor signal quality within the current preset time period of the quadruped robot, proceeds to the next step.

[0058] Specifically, such as Figure 2 As shown, the method for determining the positioning accuracy of the quadruped robot is as follows:

[0059] The number of periods of poor signal for the quadruped robot within a preset time period is obtained based on the distribution of the periods of poor signal.

[0060] The impact of different signal-poor periods on positioning accuracy was determined by the duration of different signal-poor periods and the signal quality at different times during those periods.

[0061] The number of signal-poor periods for the quadruped robot within a preset time period is obtained, and the positioning accuracy of the quadruped robot is determined by combining the impact value of different signal-poor periods on positioning accuracy and the interval duration of different signal-poor periods.

[0062] Furthermore, the positioning accuracy of the quadruped robot ranges from 0 to 1, wherein when the positioning accuracy of the quadruped robot is not less than the preset accuracy, the positioning accuracy of the quadruped robot is determined to be controllable.

[0063] Specifically, when the positioning accuracy of the quadruped robot is uncontrollable, the quadruped robot is controlled to pause its movement until the signal quality of the positioning information of the quadruped robot meets the requirements.

[0064] In another embodiment, the method for determining the positioning accuracy of the quadruped robot is as follows:

[0065] Based on the distribution of the poor signal periods, the cumulative duration of the poor signal periods of the quadruped robot within a preset time period is obtained. It is then determined whether the cumulative duration of the poor signal periods of the quadruped robot within the preset time period meets the requirements. If yes, proceed to the next step; otherwise, it is determined that the positioning accuracy of the quadruped robot cannot meet the requirements.

[0066] The update time of the nearest navigation position is used as the position update time. It is then determined whether the interval between the position update time and the current time meets the requirements. If yes, proceed to the next step; otherwise, it is determined that the positioning accuracy of the quadruped robot cannot meet the requirements.

[0067] The current period of poor signal is determined based on the location update time, and the impact value of the positioning accuracy of the current period of poor signal is determined based on the duration of the current period of poor signal and the signal quality at different times of the current period of poor signal. It is then determined whether the impact value of the positioning accuracy of the current period of poor signal meets the requirements. If yes, proceed to the next step; otherwise, it is determined that the positioning accuracy of the quadruped robot cannot meet the requirements.

[0068] The impact of different signal-poor periods on positioning accuracy is determined by the duration of different signal-poor periods and the signal quality at different times during the signal-poor periods. The number of signal-poor periods for the quadruped robot within a preset time period is obtained, and the positioning accuracy of the quadruped robot is determined by combining the impact of different signal-poor periods on positioning accuracy and the interval duration of different signal-poor periods.

[0069] S3 determines the speed information of the quadruped robot by using a speed fitting function based on the stride and frequency of the quadruped robot's four legs. Based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot, the motion attitude information of the quadruped robot is obtained by compensating for heading error and magnetic declination through the attitude angles.

[0070] like Figure 6 The diagram shows the coordinate system of the quadruped robot's carrier. The coordinate system of the quadruped robot's carrier (denoted as O) is established. b X b Y b Z b The navigation coordinate system is the Northeast-Sky coordinate system (denoted as O). n Xn Y n Z n Based on the motion characteristics of quadruped robots, the stride length of a quadruped robot is S. i The frequency is F i The walking speed V of a quadruped robot bi Where i = 1, 2, 3, 4, representing the amplitude, frequency, and speed of the four legs (left, right, front, and rear) of the quadruped robot, and the stride length S of the quadruped robot. i The frequency is F i The walking speed V of the quadruped robot's legs can be obtained in real time from the quadruped robot's motion control system. bi for

[0071]

[0072] To simplify the walking speed of the quadruped robot, the walking speed V of the quadruped robot is... b for

[0073]

[0074] Based on the measured walking speed V of the quadruped robot b Corresponding to the recorded stride length S of the quadruped robot's legs i and frequency F i Using equations (1) and (2), the walking speed V of the quadruped robot is fitted using a third-order linear model and the least squares method. b With S i F i The relationship is

[0075] V b =f(S) i ,F i (3)

[0076] The quadruped robot is placed on a level ground and in a standard standing position. Error compensation is performed based on the attitude angle information output by the quadruped robot's inertial measurement unit. This ensures that the real-time output angles of the pitch and roll angles of the quadruped robot are close to 0 degrees when it is in a standard standing position on a level ground. At this point, the attitude error compensation for the pitch and roll angles of the quadruped robot is completed.

[0077] Using a high-precision GNSS differential positioning device, a straight line with a length of at least 200 meters is marked in an open horizontal environment. The quadruped robot is then controlled to walk in a straight line according to a motion model. The minimum distance deviation between the walking line and the actual target point is recorded as Δd. The magnetic declination corresponding to the latitude and longitude coordinates of the current location is then determined. Then, calculate the compensation angle for the quadruped robot's heading angle. for

[0078]

[0079] At this point, the compensation for the quadruped robot's attitude angle error, heading angle error, and magnetic declination angle has been completed.

[0080] Step 3 Features: When the quadruped robot's satellite navigation device cannot obtain effective latitude and longitude information, navigation calculation is required. The pitch angle θ, roll angle γ, and heading angle are then calculated and compensated in real time by combining equation (3) with the quadruped robot's inertial measurement unit. The velocity V in the carrier coordinate system b Transformation of navigation coordinate system velocity V n for

[0081]

[0082] Among them, V E V E V u These represent the quadruped robot's speeds in the east, north, and sky directions, respectively, under the navigation coordinates. for

[0083]

[0084] Integrating the velocity in the navigation coordinate system yields the current longitude λ and latitude L.

[0085]

[0086] Where λ0 and L0 are the longitude and latitude of the previous moment, respectively, h is the altitude, and R is the latitude. M R N These are the radii of curvature of the Earth's meridian and trochanter, respectively.

[0087]

[0088] Where a is the major radius of the Earth's ellipsoid; e is the first eccentricity of the Earth.

[0089] Combining equations (3) to (10) above, autonomous navigation of the quadruped robot can be achieved when satellite positioning signals fail in complex environments.

[0090] Specifically, such as Figure 3 As shown, the method for determining the speed information of the quadruped robot is as follows:

[0091] A speed measuring device is used to measure the walking speed of the quadruped robot under different time states and different time state frequencies. The walking stride and frequency are used as inputs to the speed fitting function, and the speed measured by the speed measuring device is used as the output of the speed fitting function.

[0092] The parameters of a velocity fitting function, which is a combination of the quadruped robot's walking speed and its stride length and frequency, are obtained by fitting the quadruped robot's walking speed using the least squares method. Based on the velocity fitting function and the quadruped robot's stride length and frequency, the walking speed information of the quadruped robot is determined.

[0093] Specifically, the steps for constructing the motion posture information are as follows:

[0094] Using a high-precision GNSS differential positioning device, a straight line with a distance of not less than 200 meters is marked in an open horizontal environment. The quadruped robot is controlled to walk in a straight line according to the motion model. The minimum distance deviation between the walking line and the actual target point is recorded. The compensation angles of magnetic declination and heading angle corresponding to the latitude and longitude coordinates of the location are checked.

[0095] Based on the minimum distance deviation between the walking straight line and the actual target point, the compensation angles for magnetic declination and heading angle corresponding to the latitude and longitude coordinates of the current location are consulted to compensate for the heading error and magnetic declination, thereby obtaining the motion posture information of the quadruped robot.

[0096] S4 uses the information from the previous moment and the motion posture and velocity information of the quadruped robot at the current moment to calculate the navigation position, calculate the position information at the current moment, and perform posture control of the quadruped robot based on the position information and the compensation data within the current preset time period until the positioning information that meets the quality requirements is obtained, and then updates the navigation position in real time.

[0097] When satellite signals fail, the quadruped robot can complete autonomous navigation using step 3), but long-term navigation will result in the position error diverging over time. To mitigate this divergence, when the quadruped robot's satellite positioning device can obtain positioning information, the positioning information output by the satellite positioning device should be used to update the position calculated in step 3) in a timely manner. This can effectively dampen the position error divergence during long-term navigation of the quadruped robot.

[0098] Step 5: Analyzing the errors of the navigation calculation algorithm and selected sensors, the attitude and heading errors are mainly due to sensor errors. According to the YIS320 inertial measurement unit manual, the roll and pitch angle errors of the quadruped robot's navigation output are approximately 0.05° (RMS), and the heading angle error is approximately 0.3° (RMS). The quadruped robot's navigation output speed error is directly related to gait measurement accuracy, step frequency measurement accuracy, fitting model error, and terrain conditions. This error needs to be verified in conjunction with the accuracy of the integrated navigation. The position error of the quadruped robot's navigation output consists of integrated navigation calculation errors and satellite positioning errors. Based on the output accuracy of the WHEELTEC GPS / BD dual-mode GNSS positioning module, when the satellite positioning module outputs valid positioning information, the quadruped robot's latitude and longitude errors can be controlled within 10 meters, and the satellite positioning error does not accumulate and diverge over time. Therefore, the quadruped robot's position error is mainly due to integrated navigation calculation errors.

[0099] When a quadruped robot operates in a complex environment that causes its satellite positioning module to malfunction, the main navigation position error ΔS of the quadruped robot is calculated as follows:

[0100]

[0101] Where, ΔS λ ΔS L These represent the positional errors of the quadruped robot in the longitude and latitude directions, ΔV. b V represents the velocity model error after fitting the gait and step frequency of the quadruped robot. b Δθ is the walking speed of the quadruped robot, Δθ is the heading angle error after compensation by the output of the quadruped robot's inertial measurement unit, and t is the walking time of the quadruped robot.

[0102] Set the speed error ΔV of the quadruped robot b The inertial measurement unit (IMU) of the quadruped robot has an angle error Δθ of 0.3° (RMS) of 0.05 m / s, and the walking time t of the quadruped robot is 600 s. The simulation calculates the walking speed V of the quadruped robot. b The relationship between navigation position error and time at speeds of 1 m / s, 2 m / s, and 3 m / s are as follows: Figure 7 .

[0103] Step 6 Features: Construct the hardware for the quadrupedal machine navigation system, according to equations (1) to (10) and Figure 1 Navigation software was developed based on the navigation calculation principle. After development, it was run on the navigation board of the quadruped robot, enabling the quadruped robot to navigate autonomously in complex environments.

[0104] Specifically, such as Figure 4 As shown, the method for determining the posture control of the quadruped robot is as follows:

[0105] The real-time position of the quadruped robot is determined by the position information, and the position accuracy of the quadruped robot is determined based on the change between the real-time position and the position at the previous moment.

[0106] The heading error and magnetic declination compensation data at different times within a preset time period are obtained, and the positional reliability of the quadruped robot at different times is determined by combining the positional changes at different times with the previous time.

[0107] The positional accuracy of the quadruped robot is corrected by the positional reliability of the quadruped robot at different times to obtain the comprehensive positional reliability, and the attitude control of the quadruped robot is performed based on the comprehensive positional reliability.

[0108] Furthermore, the attitude control of the quadruped robot based on the comprehensive position reliability specifically includes:

[0109] When the overall position reliability meets the requirements, the quadruped robot's posture control is performed based on the travel speed corresponding to the overall position reliability.

[0110] If the overall position reliability does not meet the requirements, the quadruped robot is controlled to pause its movement until the signal quality of the quadruped robot's positioning information meets the requirements.

[0111] It is understandable that the overall positional reliability is obtained by correcting the positional accuracy of the quadruped robot through the positional reliability of the quadruped robot at different times, specifically including:

[0112] The basic weight values ​​for different times are determined based on the time elapsed between different times and the current time, and the weights of the position positioning reliability of the quadruped robot are determined by combining the position positioning reliability of the quadruped robot at different times.

[0113] The reliability correction amount is obtained by normalizing the weighted sum of the positional reliability, and the overall positional reliability is determined by summing the reliability correction amount with the positional accuracy of the quadruped robot.

[0114] In another embodiment, the method for determining the posture control of the quadruped robot is as follows:

[0115] The real-time position of the quadruped robot is determined by the position information, and the position accuracy of the quadruped robot is determined based on the change between the real-time position and the position at the previous moment. It is then determined whether the position accuracy of the quadruped robot meets the requirements. If yes, the next step is performed; otherwise, the attitude control of the quadruped robot is performed by a preset attitude control strategy.

[0116] Obtain compensation data for heading error and magnetic declination at different times within a preset time period, and determine the error compensation time based on the compensation data. Determine whether the number of deviation compensation times meets the requirements. If yes, proceed to the next step; otherwise, perform attitude control of the quadruped robot through a preset attitude control strategy.

[0117] Based on the position changes between different times and the previous time, the abnormal time of position change of the quadruped robot is determined. It is then determined whether the number of abnormal time of position change of the quadruped robot meets the requirements. If yes, proceed to the next step; otherwise, the attitude control of the quadruped robot is performed through a preset attitude control strategy.

[0118] The heading error and magnetic declination compensation data at different times within a preset time period are obtained, and the position change at different times and the previous time are combined to determine the position positioning reliability of the quadruped robot at different times. It is determined whether the number of times when the position positioning reliability does not meet the requirements is met. If yes, proceed to the next step; otherwise, the attitude control of the quadruped robot is performed through a preset attitude control strategy.

[0119] The positional accuracy of the quadruped robot is corrected by the positional reliability of the quadruped robot at different times to obtain the comprehensive positional reliability, and the attitude control of the quadruped robot is performed based on the comprehensive positional reliability.

[0120] Furthermore, when the compensation amount for either the heading error or the magnetic declination at the specified time is greater than a preset compensation threshold, the specified time is determined to be the error compensation time.

[0121] Specifically, when the change in position between the stated time and the previous time is outside the preset range, the stated time is determined to be an abnormal position change time.

[0122] It should be noted that the attitude control of the quadruped robot is achieved through a preset attitude control strategy, specifically including:

[0123] The quadruped robot is controlled to pause its movement until the signal quality of the quadruped robot's positioning information meets the requirements.

[0124] Example 2

[0125] On the other hand, such as Figure 5 As shown, this invention provides a low-cost integrated navigation system for quadruped robots in complex environments, employing the aforementioned low-cost integrated navigation method for quadruped robots in complex environments, characterized by specifically including:

[0126] Signal quality assessment module, positioning accuracy assessment module, motion attitude acquisition module, navigation processing module;

[0127] The signal quality assessment module is responsible for acquiring the positioning information of the quadruped robot in real time and determining whether the signal quality of the positioning information meets the requirements.

[0128] The positioning accuracy evaluation module is responsible for identifying periods when the signal quality does not meet the requirements as periods of poor signal quality, and determining whether the positioning accuracy of the quadruped robot is controllable based on the distribution of periods of poor signal quality within the current preset time period of the quadruped robot.

[0129] The motion attitude acquisition module is responsible for determining the speed information of the quadruped robot by using a speed fitting function based on the stride and frequency of the quadruped robot's four legs, and obtaining the motion attitude information of the quadruped robot by compensating for heading error and magnetic declination through the attitude angles based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot.

[0130] The navigation processing module is responsible for using the information of the quadruped robot in the previous moment and the motion posture and speed information in the current moment to calculate the navigation position, calculate the position information in the current moment, and perform posture control of the quadruped robot based on the position information and the compensation data in the current preset time period until the positioning information that meets the quality requirements is obtained, and then update the navigation position in real time.

[0131] Through the above embodiments, the present invention achieves the following beneficial effects:

[0132] By fully utilizing the quadrupedal robot's quadrupedal motion characteristics, low-cost satellite positioning equipment, and the quadrupedal robot's built-in inertial measurement unit, a quadrupedal robot navigation system is formed, which can meet the autonomous navigation needs of quadrupedal robots. At the same time, it effectively solves the problems of high cost and system complexity of existing quadrupedal robot navigation systems.

[0133] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, devices, and non-volatile computer storage media are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0134] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0135] The above description is merely one or more embodiments of this specification and is not intended to limit this specification. Various modifications and variations can be made to the one or more embodiments of this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of one or more embodiments of this specification should be included within the scope of the claims of this specification.

Claims

1. A low-cost integrated navigation method for quadruped robots in complex environments, characterized in that: The positioning information of the quadruped robot is acquired in real time, and when the signal quality of the positioning information does not meet the requirements, the process proceeds to the next step. The time period in which the signal quality does not meet the requirements is defined as the period of poor signal. When the positioning accuracy of the quadruped robot is determined to be controllable based on the distribution of the period of poor signal within the current preset time period of the quadruped robot, the next step is initiated. Based on the stride length and frequency of the quadruped robot, the velocity information of the quadruped robot is determined by a velocity fitting function. Based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot, the motion attitude information of the quadruped robot is obtained by compensating for heading error and magnetic declination through the attitude angles. Using the information from the previous moment and the motion posture and velocity information of the quadruped robot at the current moment, the navigation position is estimated, the current position information is calculated, and the attitude control of the quadruped robot is performed based on the position information and the compensation data within the current preset time period until the positioning information that meets the quality requirements is obtained, and the navigation position is updated in real time. The method for determining the positioning accuracy of the quadruped robot is as follows: The number of periods of poor signal for the quadruped robot within a preset time period is obtained based on the distribution of the periods of poor signal. The impact of different signal-poor periods on positioning accuracy was determined by the duration of different signal-poor periods and the signal quality at different times during those periods. The number of signal-poor periods for the quadruped robot within a preset time period is obtained, and the positioning accuracy of the quadruped robot is determined by combining the impact value of different signal-poor periods on positioning accuracy and the interval duration of different signal-poor periods. When the positioning accuracy of the quadruped robot becomes uncontrollable, the quadruped robot is controlled to pause its movement until the signal quality of the positioning information of the quadruped robot meets the requirements.

2. The low-cost integrated navigation method for quadruped robots in complex environments as described in claim 1, characterized in that, The positioning information of the quadruped robot is determined based on the quadruped robot's satellite positioning equipment.

3. The low-cost integrated navigation method for quadruped robots in complex environments as described in claim 1, characterized in that, The method for determining the signal quality of the location information is as follows: Based on the location information, the feature quantities of the location data in different signal quality dimensions are determined, and the signal quality of the location information is determined by the weights of the feature quantities in different signal quality dimensions.

4. The low-cost integrated navigation method for quadruped robots in complex environments as described in claim 1, characterized in that, When the signal quality of the positioning information meets the requirements, the navigation position is updated based on the positioning information, and navigation management is performed based on the navigation position.

5. The low-cost integrated navigation method for quadruped robots in complex environments as described in claim 1, characterized in that, The method for determining the speed information of the quadruped robot is as follows: A speed measuring device is used to measure the walking speed of the quadruped robot under different time states and different time state frequencies. The walking stride and frequency are used as inputs to the speed fitting function, and the speed measured by the speed measuring device is used as the output of the speed fitting function. The parameters of a velocity fitting function, which is a combination of the quadruped robot's walking speed and its stride length and frequency, are obtained by fitting the quadruped robot's walking speed using the least squares method. Based on the velocity fitting function and the quadruped robot's stride length and frequency, the walking speed information of the quadruped robot is determined.

6. The low-cost integrated navigation method for quadruped robots in complex environments as described in claim 1, characterized in that, The specific steps for constructing the motion posture information are as follows: Using a high-precision GNSS differential positioning device, a straight line with a distance of not less than 200 meters is marked in an open horizontal environment. The quadruped robot is controlled to walk in a straight line according to the motion model. The minimum distance deviation between the walking line and the actual target point is recorded. The compensation angles of magnetic declination and heading angle corresponding to the latitude and longitude coordinates of the location are checked. Based on the minimum distance deviation between the walking straight line and the actual target point, the compensation angles for magnetic declination and heading angle corresponding to the latitude and longitude coordinates of the current location are consulted to compensate for the heading error and magnetic declination, thereby obtaining the motion posture information of the quadruped robot.

7. A low-cost integrated navigation system for quadruped robots in complex environments, employing the low-cost integrated navigation method for quadruped robots in complex environments as described in any one of claims 1-6, characterized in that, Specifically, it includes: Signal quality assessment module, positioning accuracy assessment module, motion attitude acquisition module, navigation processing module; The signal quality assessment module is responsible for acquiring the positioning information of the quadruped robot in real time and determining whether the signal quality of the positioning information meets the requirements. The positioning accuracy evaluation module is responsible for identifying periods when the signal quality does not meet the requirements as periods of poor signal quality, and determining whether the positioning accuracy of the quadruped robot is controllable based on the distribution of periods of poor signal quality within the current preset time period of the quadruped robot. The motion attitude acquisition module is responsible for determining the speed information of the quadruped robot by using a speed fitting function based on the stride and frequency of the quadruped robot's four legs, and obtaining the motion attitude information of the quadruped robot by compensating for heading error and magnetic declination through the attitude angles based on the three attitude angles output in real time by the inertial measurement unit installed on the quadruped robot. The navigation processing module is responsible for using the information of the quadruped robot in the previous moment and the motion posture and speed information in the current moment to calculate the navigation position, calculate the position information in the current moment, and perform posture control of the quadruped robot based on the position information and the compensation data in the current preset time period until the positioning information that meets the quality requirements is obtained, and then update the navigation position in real time.

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