Robot obstacle avoidance method and system based on cooperation of joints and driving wheels

Abstract

The invention relates to the technical field of robot obstacle avoidance, and provides a robot obstacle avoidance method and system based on cooperation of joints and driving wheels, and the obstacle avoidance method comprises the steps: S1, an identification module identifies an obstacle on an advancing path; s2, according to the recognition result, a first motor is used for driving a driving wheel and / or a second motor is used for driving a lifting joint module to execute an obstacle avoidance action; and S3, adjusting target rotating speeds of the first motor and the second motor according to the obstacle avoidance action. Through cooperation of the joints and the driving wheels, the robot adjusts the obstacle avoidance action when encountering an obstacle, and the capacity of passing through a complex environment is improved; the target rotating speed of the motor is adjusted in real time to ensure accurate and efficient obstacle avoidance action; the motor performance is optimized through current control and parameter adjustment, and the stability and the response speed of the robot during obstacle avoidance are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of robot obstacle avoidance, and in particular to a robot obstacle avoidance method and system based on cooperation of joints and driving wheels. Background Art

[0002] With the rapid development of robotics, autonomous navigation and obstacle avoidance capabilities of intelligent robots in complex environments have become key research areas. Traditional obstacle avoidance methods usually rely on a single moving part, such as wheels or tracks, which may show limitations when facing various obstacles. To address this problem, more and more robotic systems are beginning to combine multiple moving parts and control mechanisms to achieve more efficient obstacle avoidance capabilities.

[0003] Therefore, it is necessary to propose a robot obstacle avoidance method based on the collaboration of joints and drive wheels, aiming to improve the robot's obstacle avoidance performance in complex environments. Summary of the invention

[0004] In view of the above-mentioned defects, the purpose of the present invention is to propose a robot obstacle avoidance method and system based on the collaboration of joints and drive wheels, aiming to flexibly adjust the robot's obstacle avoidance action according to the different distances between the robot and the obstacle, and use the feedback of the obstacle avoidance action to adjust the target speed of the motor.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A robot obstacle avoidance method based on cooperation of joints and driving wheels, the obstacle avoidance method is applied to a robot based on cooperation of joints and driving wheels, the robot comprising: an identification module, a driving wheel, a lifting joint module, a top body, a first motor and a second motor, the driving wheel is located at the bottom of the robot, the lifting joint module is installed above the driving wheel, and the lifting joint module is used to lift the top body up and down;

[0007] The obstacle avoidance method comprises:

[0008] Step S1: The recognition module recognizes obstacles on the travel path;

[0009] Step S2: using the first motor to drive the driving wheel and / or using the second motor to drive the lifting joint module to perform an obstacle avoidance action according to the recognition result;

[0010] Step S3: adjusting the target rotation speeds of the first motor and the second motor according to the obstacle avoidance action.

[0011] Preferably, in step S2, using the first motor to drive the driving wheel and / or using the second motor to drive the lifting joint module to perform the obstacle avoidance action according to the recognition result includes:

[0012] When the minimum distance between the obstacle on the travel path and the ground is greater than the distance between the top of the top body and the ground minus the current descent limit value of the lifting joint module, the second motor is used to control the lifting joint module to perform a corresponding obstacle avoidance action;

[0013] When the minimum distance between the obstacle on the travel path and the ground is less than the distance between the top of the top body and the ground minus the current descent limit value of the lifting joint module, if there is an obstacle within the preset range of the travel path or the distance between the obstacle and the ground is greater than the distance between the top body and the ground, the first motor is used to control the driving wheel to perform a corresponding obstacle avoidance action;

[0014] If the distance between an obstacle within a preset range of the travel path and the ground is less than the distance between the top body and the ground and the distance between the top of the top body and the ground minus the current descent limit value of the lifting joint module, the first motor and the second motor are used to respectively drive the driving wheel and the lifting joint module to perform corresponding obstacle avoidance actions.

[0015] Preferably, the obstacle avoidance action of the lifting joint module includes the lifting joint module extending and retracting according to the extension and retraction range and the extension and retraction speed to make the top body rise and fall;

[0016] The obstacle avoidance action of the driving wheel includes the driving wheel steering the robot according to the steering amplitude and the steering angular velocity.

[0017] Further, the step S3 includes: the second motor adjusts the corresponding target rotation speed according to the extension and retraction speed of the lifting joint module;

[0018] The first motor adjusts the corresponding target rotation speed according to the steering amplitude and steering angular velocity of the driving wheel.

[0019] Furthermore, if the actual distance between the robot and the obstacle is less than a preset obstacle avoidance danger distance, the extension and retraction speed of the lifting joint module or the steering amplitude and steering angular velocity of the driving wheel are adjusted according to the obstacle avoidance danger distance and the actual distance;

[0020] The telescopic speed of the lifting joint module satisfies the relationship:

[0021] V extend =k extend ×(D safe -D obs );

[0022] Among them, V extend represents the extension and retraction speed of the lifting joint module, k extend It represents the adjustment coefficient of the extension and retraction speed determined by the lifting joint module, D safe Indicates the preset obstacle avoidance danger distance, D obsIndicates the actual distance between the robot and the obstacle;

[0023] The steering amplitude of the driving wheel satisfies the relationship:

[0024] θ steer =k steer ×(D safe -D obs ) / D safe ;

[0025] Among them, θ steer Indicates the steering range of the driving wheel, k steer Indicates the adjustment coefficient of the steering range determined by the driving wheel, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle;

[0026] ω steer =k ω ×(D safe -D obs ) / D safe ;

[0027] Among them, ω steer represents the steering angular velocity of the driving wheel, k ω Indicates the adjustment coefficient of the steering angular velocity determined by the driving wheel, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle.

[0028] Further, in step S3, adjusting the target speeds of the first motor and the second motor according to the avoidance action includes:

[0029] When the extension and retraction speed of the lifting joint module or the steering amplitude and steering angular velocity of the driving wheel change so that the target speed of the first motor or the second motor changes, it is determined whether the target speed of the first motor or the second motor is lower than the preset motor turning speed. If so, the current control method of MTPA is used to generate the corresponding d-axis and q-axis currents;

[0030] The d-axis current and the q-axis current are input into the controller to obtain the d-axis and q-axis voltages, and the first motor or the second motor is driven to operate according to the d-axis and q-axis voltages.

[0031] Further, in step S3, after adjusting the target speeds of the first motor and the second motor according to the avoidance action, the method further includes:

[0032] When the extension and retraction speed of the lifting joint module or the steering amplitude and steering angular velocity of the driving wheel change so that the target speed of the first motor or the second motor changes, it is determined whether the target speed of the first motor or the second motor is higher than the preset motor turning speed. If so, the current of the d-axis is obtained according to the operating parameters, design parameters and target speed of the motor, and the limit value of the q-axis current is obtained according to the maximum current and the current of the d-axis;

[0033] The d-axis current and the q-axis current are input into the controller to obtain the d-axis and q-axis voltages, and the first motor or the second motor is driven to operate according to the d-axis and q-axis voltages.

[0034] Preferably, the operating parameters include: a given current of the q-axis, a feedback current of the q-axis;

[0035] The design parameters include: rated current of the motor and rated speed of the motor.

[0036] Furthermore, the step of obtaining the current of the d-axis is as follows:

[0037] Get the given current I of the q axis in real time qRef , the given current I qRef Input to the low-pass filter to get the first parameter I q ′ Ref ;

[0038] Get the feedback current I of the q axis in real time q , the given current I q Input to the low-pass filter to obtain the second parameter I q ′ ;

[0039] Get the first parameter I q ′ Ref With the second parameter I q ′ The difference E is used as the input of the PI controller to obtain the current feedback given term D1;

[0040] According to the rated current I n and rated speed ω n Calculate the amplification factor Kc of the current feedforward given term;

[0041] Obtain the current speed increment, adjust the speed increment by the amplification factor Kc, and obtain the current feedback given item D2;

[0042] The d-axis current I is obtained by adding the feedback given term D1 and the feedforward given term D2. d .

[0043] A robot obstacle avoidance system based on cooperation between joints and driving wheels, the obstacle avoidance system is applied to a robot based on cooperation between joints and driving wheels, the robot comprises: an identification module, a driving wheel, a lifting joint module, a top body, a first motor and a second motor, the driving wheel is located at the bottom of the robot, the lifting joint module is installed above the driving wheel, and the lifting joint module is used to lift the top body up and down;

[0044] The obstacle avoidance system comprises:

[0045] An obstacle recognition module, used to control the recognition module to recognize obstacles on the travel path;

[0046] A control decision module, configured to use the first motor to drive the driving wheel and / or use the second motor to drive the lifting joint module to perform an obstacle avoidance action according to the recognition result;

[0047] A motor control module is used to adjust the target speeds of the first motor and the second motor according to the obstacle avoidance action.

[0048] One of the above technical solutions has the following advantages or beneficial effects:

[0049] Through the collaboration of joints and drive wheels, the robot adjusts its obstacle avoidance actions when encountering obstacles, improving its ability to pass through complex environments; it adjusts the target speed of the motor in real time to ensure that the obstacle avoidance actions are accurate and efficient; it uses current control and parameter adjustment to optimize motor performance and improve the robot's stability and reaction speed when avoiding obstacles; it adjusts the robot's speed when avoiding obstacles according to the distance between the robot and the obstacle, allowing the robot to accurately avoid obstacles even when there is a delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0051] Figure 1 is a flow chart of a robot obstacle avoidance method based on cooperation between joints and driving wheels provided in an embodiment of the present invention;

[0052] Figure 2 is a schematic diagram of a robot obstacle avoidance system based on cooperation of joints and driving wheels provided in an embodiment of the present invention;

[0053] Figure 3 is a schematic diagram of the robot structure of the robot obstacle avoidance method based on the cooperation of joints and driving wheels provided in an embodiment of the present invention;

[0054] Among them, there are a driving wheel 10, a lifting joint module 20, a top body 30, a first motor 110, and a second motor 210. DETAILED DESCRIPTION

[0055] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0056] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0057] like Figure 1 As shown, a preferred embodiment of the present application is a robot obstacle avoidance method based on the cooperation of joints and driving wheels, the obstacle avoidance method is applied to a robot based on the cooperation of joints and driving wheels, the robot comprising: an identification module, a driving wheel 10, a lifting joint module 20, a top body 30, a first motor 110 and a second motor 210;

[0058] The obstacle avoidance method comprises:

[0059] Step S1: The recognition module recognizes obstacles on the travel path;

[0060] Step S2: using the first motor 110 to drive the driving wheel 10 and / or using the second motor 210 to drive the lifting joint module 20 to perform an obstacle avoidance action according to the recognition result;

[0061] Step S3: adjusting the target rotation speeds of the first motor 110 and the second motor 210 according to the obstacle avoidance action.

[0062] Specifically, in this embodiment, in order to further better illustrate the technical principle of this method, the following is provided: Figure 3 The schematic diagram corresponding to the existing structure of the robot based on the cooperation of joints and driving wheels is shown. In actual application, the adapted robot only needs to include an identification module, a driving wheel, a lifting joint module, a top body, a first motor and a second motor to adopt the obstacle avoidance method described in this application. Figure 3In the robot schematic diagram in FIG. 1 , the robot can be understood as comprising: an even number of driving wheels 10, the driving wheels 10 are arranged at the bottom of the robot, a lifting joint module 20 is arranged above the driving wheels 10, the lifting joint module 20 is coordinated by a number of joints to achieve lifting, and a top body 30 is arranged above the lifting joint module 20. The top body 30 can be replaced to adapt to various functions and scenarios. For example, the top body 30 can be configured to place or support objects, and the driving wheels 10 are used to realize functions such as conveying objects. The identification module ( Figure 3 The first motor 110 can provide power for the driving wheel 10 to drive it to perform corresponding obstacle avoidance actions, so that the robot as a whole can avoid obstacles. The second motor 210 can provide power for the lifting joint module 20 to drive the top body 30 to rise and fall, and make the top body 30 drop when obstacle avoidance is needed, and restore the original height after obstacle avoidance.

[0063] When the robot is traveling along the travel path, the recognition module detects obstacles on the robot's travel path through sensors (such as cameras, laser radars, ultrasonic sensors, etc.). After collecting data using the sensors, the recognition module determines the location of the obstacle through algorithms such as image processing and data analysis. If an obstacle is identified on the travel path, the first motor 110 can be used to drive the driving wheel 10 to change the travel direction of the robot to bypass the obstacle, or the second motor 210 can be used to drive the lifting joint module 20 to adjust the height of the top of the robot's top body 30 so that it can avoid the obstacle, or the two can be combined to coordinate and avoid the obstacle, and then continue to operate along the travel path. When working, the target speed of the motor needs to be adjusted according to the specific degree of realization of the obstacle avoidance action. The adjustment of the motor speed can provide sufficient power to support the robot's obstacle avoidance activities when obstacle avoidance is required. When obstacle avoidance is not required, the motor speed can be reduced to reduce the power consumption of the motor. Through the cooperation of the joints and the drive wheels 10, the robot adjusts the obstacle avoidance action when encountering obstacles and improves the ability to pass through complex environments; the target speed of the motor is adjusted in real time to ensure that the obstacle avoidance action is accurate and efficient; the current control and parameter adjustment are used to optimize the motor performance and improve the stability and reaction speed of the robot when avoiding obstacles.

[0064] Preferably, in step S2, using the first motor 110 to drive the driving wheel 10 and / or using the second motor 210 to drive the lifting joint module 20 to perform the obstacle avoidance action according to the recognition result includes:

[0065] When the minimum distance between the obstacle on the travel path and the ground is greater than the distance between the top of the top body 30 and the ground minus the current descent limit value of the lifting joint module 20, the second motor 210 is used to control the lifting joint module 20 to perform a corresponding obstacle avoidance action;

[0066] When the minimum distance between an obstacle on the travel path and the ground is less than the distance between the top of the top body 30 and the ground minus the current descent limit value of the lifting joint module 20, if there is no obstacle within the preset range of the travel path or the distance between the obstacle and the ground is greater than the distance between the top body 30 and the ground, the first motor 110 is used to control the drive wheel 10 to perform a corresponding obstacle avoidance action; if the distance between the obstacle within the preset range of the travel path and the ground is less than the distance between the top body 30 and the ground and the distance between the top of the top body 30 and the ground minus the current descent limit value of the lifting joint module 20, the first motor 110 and the second motor 210 are used to respectively drive the drive wheel 10 and the lifting joint module 20 to perform a corresponding obstacle avoidance action.

[0067] Specifically, when the minimum distance between the obstacle on the travel path and the ground is greater than the distance between the top of the top body 30 and the ground minus the current descent limit value of the lifting joint module 20, that is, the obstacle is in a suspended state, when the robot encounters this obstacle, the robot can lower the position of the top body 30 so that the robot can pass through the bottom of the obstacle according to the travel path. For example, the distance between the top of the top body 30 and the ground is 50 cm, and the descent limit value of the lifting joint module 20 is 10 cm. This means that in a normal state, the distance between the top body 30 and the ground is 50 cm, and the lifting joint module 20 can lower the top of the top body 30 of the robot by 10 cm. In the lowest case, the robot can pass through an obstacle with a height of 40 cm. Assuming that there is an obstacle on the travel path, its minimum distance from the ground is 45 cm. Because the height of the obstacle (45 cm) is greater than the lowest passing height of the robot (40 cm), that is, the obstacle can be passed in the current state, the second motor 210 is used to control the lifting joint module 20 to adjust the position of the top body 30 to avoid collision with the obstacle.

[0068] If it is not possible to avoid obstacles on the travel path by controlling the lifting joint module 20 to lift and lower, it is determined that there are no obstacles within the preset range of the travel path or the robot can pass through without adjusting the lifting joint module 20. For example, the distance between the top of the top body 30 and the ground is assumed to be 60 cm, and the descent limit value of the lifting joint module 20 is assumed to be 15 cm. If there are no other obstacles within the preset range of the travel path, or the height of the obstacle is greater than the overall height of the robot (60 cm), this indicates that these obstacles have no effect on the passage of the robot, and the first motor 110 is controlled to drive the driving wheel 10 to turn to avoid the obstacle; if the height of the obstacle within the preset range of the travel path is greater than 45 cm and less than 60 cm, this means that the obstacles within the preset range will hinder the robot, that is, the first motor 110 can be used to drive the driving wheel 10 to turn, and then the second motor 210 can be used to control the lifting joint module 20 to lower the top body 30 to complete the avoidance of the obstacle.

[0069] Preferably, the obstacle avoidance action of the lifting joint module includes the lifting joint module 20 extending and retracting according to the extension and retraction range and the extension and retraction speed to make the top body 30 rise and fall;

[0070] The obstacle avoidance action of the driving wheel 10 includes the driving wheel 10 steering the robot according to the steering amplitude and the steering angular velocity.

[0071] Specifically, the lifting joint module 20 can avoid obstacles with the lowest power consumption by adjusting the telescopic range, and can avoid obstacles in the shortest time within a limited distance by adjusting the telescopic speed, thereby improving the speed and success rate of obstacle avoidance.

[0072] By adjusting the steering amplitude of the driving wheel 10, the robot can accurately control the direction of travel and bypass obstacles. The precise steering ability enables the robot to move forward smoothly in narrow or complex environments and reduce the risk of collision. Different obstacles or paths require different steering amplitudes. According to the size and position of the obstacle, adjusting the steering amplitude helps the robot better adapt to the environment and avoid obstacles. At the same time, adjusting the steering angular velocity can enable the robot to change direction quickly, avoid dynamic obstacles or adjust the path in time. High angular velocity helps the robot complete sharp turns in a short time and improves obstacle avoidance efficiency. By optimizing the steering angular velocity, the robot can quickly respond to changing environments while maintaining stability. Reasonable steering speed can avoid loss of control or tilting caused by turning too fast.

[0073] Further, the step S3 includes: the first motor 110 adjusts the corresponding target rotation speed according to the extension and retraction speed of the lifting joint module 20;

[0074] The second motor 210 adjusts the corresponding target rotation speed according to the steering amplitude and steering angular velocity of the driving wheel 10 .

[0075] Among them, the second motor 210 is responsible for driving the lifting joint module 20. According to the extension and retraction speed of the lifting joint module 20, the motor needs to adjust its target speed to ensure that the lifting joint module 20 can be extended and retracted at an appropriate speed. The extension and retraction speed determines the rate of height change that the robot can achieve during the lifting process. By adjusting the target speed of the second motor 210, the motor can accurately control the movement of the lifting joint to ensure that the lifting task is completed within the specified time.

[0076] The first motor 110 is responsible for driving the driving wheel 10. According to the steering amplitude and steering angular velocity of the driving wheel 10, the motor needs to adjust its target speed to ensure that the wheel can turn at the correct speed. The steering amplitude and angular velocity determine the accuracy and rapidity of the robot's steering. By adjusting the target speed of the first motor 110, the motor can ensure that the driving wheel 10 turns at an appropriate speed, thereby achieving precise movement and path adjustment.

[0077] Furthermore, if the actual distance between the robot and the obstacle is less than the preset obstacle avoidance danger distance, the extension and retraction speed of the lifting joint module 20 or the steering amplitude and steering angular velocity of the driving wheel 10 are adjusted according to the obstacle avoidance danger distance and the actual distance;

[0078] The telescopic speed of the lifting joint module 20 satisfies the relationship:

[0079] V extend =k extend ×(D safe -D obs );

[0080] Among them, V extend represents the extension and retraction speed of the lifting joint module, k extend It represents the adjustment coefficient of the extension and retraction speed determined by the lifting joint module, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle;

[0081] The steering amplitude of the driving wheel 10 satisfies the relationship:

[0082] θ steer =k steer ×(D safe -D obs ) / D safe ;

[0083] Among them, θ steer Indicates the steering range of the driving wheel, k steer Indicates the adjustment coefficient of the steering range determined by the driving wheel, D safe Indicates the preset obstacle avoidance danger distance, Dobs Indicates the actual distance between the robot and the obstacle;

[0084] ω steer =k ω ×(D safe -D obs ) / D safe ;

[0085] Among them, ω steer represents the steering angular velocity of the driving wheel, k ω Indicates the adjustment coefficient of the steering angular velocity determined by the driving wheel, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle.

[0086] Specifically, there may be a delay in the actual obstacle avoidance process, that is, when the robot starts to avoid obstacles, the distance from the obstacle has entered the dangerous distance. The extension and retraction speed of the lifting joint module 20 is determined by the difference between the preset obstacle avoidance dangerous distance and the actual distance, and the adjustment coefficient is determined by the lifting joint module 20 itself. The steering amplitude and angular velocity of the driving wheel 10 are also adjusted in a similar manner to ensure that the robot can maintain a stable steering when avoiding obstacles and can quickly and effectively change the travel path. For example, assuming the preset obstacle avoidance dangerous distance D safe is 1m, the actual distance between the robot and the obstacle is D obs is 0.6m, the adjustment coefficient k of the telescopic speed extend The adjustment coefficient of the steering range and the adjustment coefficient of the steering angular velocity are set to 0.5 and 0.3 respectively according to the conditions of the lifting joint module 20. When the lifting joint module 20 is required to operate, the extension speed V extend is 0.32 m / s. When the driving wheel 10 needs to turn to avoid obstacles, the turning amplitude θ of the driving wheel 10 is steer is 0.2 radians, and the steering angular velocity ω steer The specific motion states of the lifting joint module 20 and the driving wheel 10 during different obstacle avoidance actions are adjusted according to different distances to achieve precise obstacle avoidance.

[0087] Furthermore, in step S3, because the target speed of the motor needs to be continuously adjusted according to the obstacle avoidance action, the greater the degree of execution of the obstacle avoidance action at the next moment, such as a larger steering amplitude or a larger steering angular velocity, the target speed of the motor will increase, and the smaller the degree of execution of the obstacle avoidance action at the next moment, the target speed of the motor will decrease.

[0088] When the extension and retraction speed of the lifting joint module 20 or the steering amplitude and steering angular velocity of the driving wheel 10 change so that the target speed of the first motor 110 or the second motor 210 changes, it is determined whether the target speed of the first motor 110 or the second motor 210 is lower than the preset motor turning speed. If so, the MTPA current control method is used to generate the corresponding d-axis and q-axis currents;

[0089] The d-axis current and the q-axis current are input into the controller to obtain the d-axis and q-axis voltages, and the first motor 110 or the second motor 210 is driven to operate according to the d-axis and q-axis voltages.

[0090] Specifically, in order to use the minimum current to generate the maximum motor speed, the MTPA current control method is adopted, in which the output current I is divided into the current I output to the d-axis d And the current I output to the q axis q , where the current I q The main control is the current in the torque direction, where the current I d The main control is the current in the direction of the magnetic field. This embodiment is mainly to weaken the motor magnetic field and reduce the back electromotive force when the power input voltage is limited, so as to achieve the purpose of increasing the motor speed. For this reason, in the present invention, it is first determined whether the current speed is lower than the turning speed. Because when the current speed is lower than the turning speed, it means that the motor is still running in the constant torque area, and there is no need to reduce the motor back electromotive force or increase the speed by weakening the magnetic flux. At this time, the MTPA method is used to reduce the current I d Set it to 0 and then calculate the minimum current I q To generate as much torque as possible, so that the motor can quickly increase the speed, so that the current speed rises rapidly, because in I d = 0, the motor's d-axis current is always zero, reducing the electromagnetic interference and vibration caused by the change of d-axis current, which helps to maintain the stable operation of the motor. q ,I d Inverse PARK transformation is performed to generate Ua and Ub control signals, which are then sent to the SVPWM module to generate drive signals to control the motor.

[0091] In another embodiment, in step S3, adjusting the target speeds of the first motor 110 and the second motor 210 according to the avoidance action includes:

[0092] When the extension and retraction speed of the lifting joint module 20 or the steering amplitude and steering angular velocity of the driving wheel 10 change so that the target speed of the first motor 110 or the second motor 210 changes, it is determined whether the target speed of the first motor 110 or the second motor 210 is higher than the preset motor turning speed. If so, the current of the d-axis is obtained according to the operating parameters, design parameters and target speed of the motor, and the limit value of the q-axis current is obtained according to the maximum current and the current of the d-axis;

[0093] The d-axis current and the q-axis current are input into the controller to obtain the d-axis and q-axis voltages, and the first motor 110 or the second motor 210 is driven to operate according to the d-axis and q-axis voltages.

[0094] Specifically, when the target speed of the first motor 110 or the second motor 210 is higher than the preset motor turning speed, the output of the motor will increase, resulting in an increase in the magnetic flux level inside the motor, and the motor will consume more energy to maintain the magnetic field. Therefore, in order to reduce the magnetic flux, when the target speed of the first motor 110 or the second motor 210 is higher than the preset motor turning speed, the d-axis current is controlled and the q-axis current is limited based on the operating parameters and design parameters, which can accelerate the achievement of the target stride and step frequency requirements, and at the same time limit the q-axis current. If the q-axis current I d If the current command is too high, the motor may generate large torque fluctuations during dynamic response, affecting the stable operation of the motor. By limiting the q-axis current command, the torque fluctuation can be reduced and the stability of the motor can be enhanced. q ,I d Inverse PARK transformation is performed to generate Ua and Ub control signals, which are then sent to the SVPWM module to generate drive signals to control the motor.

[0095] Preferably, the operating parameters include: a given current of the q-axis, a feedback current of the q-axis;

[0096] The design parameters include: rated current of the motor and rated speed of the motor.

[0097] The steps of obtaining the current of the d-axis are as follows:

[0098] Get the given current I of the q axis in real time qRef , the given current I qRef Input to the low-pass filter to get the first parameter I q ′ Ref ;

[0099] Get the feedback current I of the q axis in real time q , the given current I q Input to the low-pass filter to obtain the second parameter I q ′ ;

[0100] Get the first parameter I q ′ Ref With the second parameter I q ′ The difference E is used as the input of the PI controller to obtain the current feedback given term D1;

[0101] According to the rated current I n and rated speed ω n Calculate the amplification factor Kc of the current feedforward given term;

[0102] Obtain the current speed increment, adjust the speed increment by the amplification factor Kc, and obtain the current feedback given item D2;

[0103] The d-axis current I is obtained by adding the feedback given term D1 and the feedforward given term D2. d .

[0104] Specifically, when the motor-driven robot performs obstacle avoidance, by obtaining the given current and feedback current of the q-axis in real time and applying a low-pass filter for processing, a more stable and accurate current parameter can be obtained. This method helps to accurately control the operation of the motor and improve stability and reliability. By calculating the difference E between the given current and the feedback current and using it as the input of the PI controller, a feedback given item D1 for adjusting the current can be obtained. The PI controller can effectively reduce errors and improve the accuracy of current control. The determination of the calculated amplification factor Kc is based on the rated current and rated speed of the motor. The speed increment is adjusted by the amplification factor Kc, which can ensure that the motor runs in an efficient and stable state. In the present invention, feedback control and feedforward control are combined, and the current of the d-axis is obtained by a simple addition operation. The d-axis current can also be accurately obtained without relying on a complex algorithm, and the feedforward given item D1 of the current can improve the speed response of the motor speed during rapid switching, and the feedback given item of the current ensures the speed stability of the motor under heavy load conditions. The method has a small amount of calculation, a simple structure, and high operating stability.

[0105] like Figure 2 As shown, a robot obstacle avoidance system based on cooperation of joints and driving wheels, the obstacle avoidance system is applied to a robot based on cooperation of joints and driving wheels, the robot comprises: an identification module, a driving wheel 10, a lifting joint module 20, a top body 30, a first motor 110 and a second motor 210, the driving wheel 10 is located at the bottom of the robot, the lifting joint module 20 is installed above the driving wheel 10, and the lifting joint module 20 is used to lift the top body 30 up and down;

[0106] The obstacle avoidance system comprises:

[0107] The obstacle recognition module 1 is used to control the recognition module to recognize obstacles on the travel path;

[0108] A control decision module 2, configured to use the first motor 110 to drive the driving wheel 10 and / or use the second motor 210 to drive the lifting joint module 20 to perform an obstacle avoidance action according to the recognition result;

[0109] The motor control module 3 is used to adjust the target rotation speeds of the first motor 110 and the second motor 210 according to the obstacle avoidance action.

[0110] This embodiment implements a robot obstacle avoidance method and implementation process based on the collaboration of joints and driving wheels. Please refer to the above embodiments and will not go into details here.

[0111] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0112] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A robot obstacle avoidance method based on cooperation between joints and driving wheels, the obstacle avoidance method being applied to a robot based on cooperation between joints and driving wheels, the robot comprising: An identification module, a driving wheel, a lifting joint module, a top body, a first motor and a second motor, wherein the driving wheel is located at the bottom of the robot, the lifting joint module is installed above the driving wheel, and the lifting joint module is used to lift the top body up and down; Characterized in that the obstacle avoidance method comprises: Step S1: The recognition module recognizes obstacles on the travel path; Step S2: using the first motor to drive the driving wheel and / or using the second motor to drive the lifting joint module to perform an obstacle avoidance action according to the recognition result; Step S3: adjusting the target rotation speeds of the first motor and the second motor according to the obstacle avoidance action.

2. The robot obstacle avoidance method according to claim 1, characterized in that: In step S2, using the first motor to drive the driving wheel and / or using the second motor to drive the lifting joint module to perform an obstacle avoidance action according to the recognition result includes: When the minimum distance between the obstacle on the travel path and the ground is greater than the distance between the top of the top body and the ground minus the current descent limit value of the lifting joint module, the second motor is used to control the lifting joint module to perform a corresponding obstacle avoidance action; When the minimum distance between the obstacle on the travel path and the ground is less than the distance between the top of the top body and the ground minus the current descent limit value of the lifting joint module, if there is an obstacle within the preset range of the travel path or the distance between the obstacle and the ground is greater than the distance between the top body and the ground, the first motor is used to control the driving wheel to perform a corresponding obstacle avoidance action; If the distance between an obstacle within a preset range of the travel path and the ground is less than the distance between the top body and the ground and the distance between the top of the top body and the ground minus the current descent limit value of the lifting joint module, the first motor and the second motor are used to respectively drive the driving wheel and the lifting joint module to perform corresponding obstacle avoidance actions.

3. The robot obstacle avoidance method according to claim 1, characterized in that: The obstacle avoidance action of the lifting joint module includes the lifting joint module extending and retracting according to the extension and retraction range and the extension and retraction speed to make the top body rise and fall; The obstacle avoidance action of the driving wheel includes the driving wheel steering the robot according to the steering amplitude and the steering angular velocity.

4. The robot obstacle avoidance method according to claim 3, characterized in that: The step S3 includes: the second motor adjusts the corresponding target rotation speed according to the extension and retraction speed of the lifting joint module; The first motor adjusts the corresponding target rotation speed according to the steering amplitude and steering angular velocity of the driving wheel.

5. The robot obstacle avoidance method according to claim 3, characterized in that: If the actual distance between the robot and the obstacle is less than the preset obstacle avoidance danger distance, the extension and retraction speed of the lifting joint module or the steering amplitude and steering angular velocity of the driving wheel are adjusted according to the obstacle avoidance danger distance and the actual distance; The telescopic speed of the lifting joint module satisfies the relationship: V extend =k extend ×(D safe -D obs ); Among them, V extend represents the extension and retraction speed of the lifting joint module, k extend It represents the adjustment coefficient of the extension and retraction speed determined by the lifting joint module, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle; The steering amplitude of the driving wheel satisfies the relationship: θ steer =k steer ×(D safe -D obs ) / D safe ; Among them, θ steer Indicates the steering range of the driving wheel, k steer Indicates the adjustment coefficient of the steering range determined by the driving wheel, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle; ω steer =k ω ×(D safe -D obs ) / D safe ; Among them, ω steer represents the steering angular velocity of the driving wheel, k ω Indicates the adjustment coefficient of the steering angular velocity determined by the driving wheel, D safe Indicates the preset obstacle avoidance danger distance, D obs Indicates the actual distance between the robot and the obstacle.

6. The robot obstacle avoidance method according to claim 5, characterized in that: In step S3, adjusting the target speeds of the first motor and the second motor according to the avoidance action includes: When the extension and retraction speed of the lifting joint module or the steering amplitude and steering angular velocity of the driving wheel change so that the target speed of the first motor or the second motor changes, it is determined whether the target speed of the first motor or the second motor is lower than the preset motor turning speed. If so, the current control method of MTPA is used to generate the corresponding d-axis and q-axis currents; The d-axis current and the q-axis current are input into the controller to obtain the d-axis and q-axis voltages, and the first motor or the second motor is driven to operate according to the d-axis and q-axis voltages.

7. The robot obstacle avoidance method according to claim 5, characterized in that: In step S3, adjusting the target speeds of the first motor and the second motor according to the avoidance action includes: When the extension and retraction speed of the lifting joint module or the steering amplitude and steering angular velocity of the driving wheel change so that the target speed of the first motor or the second motor changes, it is determined whether the target speed of the first motor or the second motor is higher than the preset motor turning speed. If so, the current of the d-axis is obtained according to the operating parameters, design parameters and target speed of the motor, and the limit value of the q-axis current is obtained according to the maximum current and the current of the d-axis; The d-axis current and the q-axis current are input into the controller to obtain the d-axis and q-axis voltages, and the first motor or the second motor is driven to operate according to the d-axis and q-axis voltages.

8. The robot obstacle avoidance method according to claim 7, characterized in that: The operating parameters include: given current of q axis, feedback current of q axis; The design parameters include: rated current of the motor and rated speed of the motor.

9. The robot obstacle avoidance method according to claim 8, characterized in that: The steps of obtaining the current of the d-axis are as follows: Get the given current I of the q axis in real time qRef , the given current I qRef Input to the low-pass filter to get the first parameter I' qRef ; Get the feedback current I of the q axis in real time q , the given current I q Input to the low-pass filter to obtain the second parameter I' q ; Get the first parameter I' qRef and the second parameter I′ q The difference E is used as the input of the PI controller to obtain the current feedback given term D1; According to the rated current I n and rated speed ω n Calculate the amplification factor Kc of the current feedforward given term; Obtain the current speed increment, adjust the speed increment by the amplification factor Kc, and obtain the current feedback given item D2; The d-axis current I is obtained by adding the feedback given term D1 and the feedforward given term D2. d .

10. A robot obstacle avoidance system based on cooperation between joints and driving wheels, characterized in that: The obstacle avoidance system is applied to a robot based on the cooperation of joints and driving wheels, the robot comprising: an identification module, a driving wheel, a lifting joint module, a top body, a first motor and a second motor, the driving wheel is located at the bottom of the robot, the lifting joint module is installed above the driving wheel, and the lifting joint module is used to lift the top body up and down; The obstacle avoidance system comprises: An obstacle recognition module, used to control the recognition module to recognize obstacles on the travel path; A control decision module, used for using the first motor to drive the driving wheel and / or using the second motor to drive the lifting joint module to perform obstacle avoidance action according to the recognition result; A motor control module is used to adjust the target speeds of the first motor and the second motor according to the obstacle avoidance action.

Images