Series-parallel manipulator and trajectory planning method of manipulator

Abstract

The application discloses a hybrid serial-parallel manipulator and a trajectory planning method thereof, and belongs to the field of production line equipment.The technical scheme of the application is as follows: a hybrid serial-parallel manipulator comprises a connecting frame, a sliding swing lever mechanism and two first linear driving mechanisms are installed on the connecting frame, the first linear driving mechanisms jointly drive the sliding swing lever mechanism to move, a connecting rod mechanism is installed at a swing end of the sliding swing lever mechanism, the connecting rod mechanism comprises at least two rod bodies connected in series through rotary pairs and / or moving pairs, one end of the connecting rod mechanism is hinged to the swing end of the sliding swing lever mechanism, and a material taking executor is installed at the other end of the connecting rod mechanism.The application has the beneficial effects that: through the combination of the parallel module and the serial module, the stability of the overall installation end of the manipulator is ensured, the carrying capacity of the overall manipulator is improved, the operation range of the manipulator is improved, the overall manipulator has multiple redundant degrees of freedom, the movement is more flexible, the trajectory of the manipulator is optimized, and the manipulator can operate more efficiently.

Description

Technical Field

[0001] This invention relates to the field of production line equipment, and in particular to a hybrid robotic arm and a trajectory planning method for the robotic arm. Background Technology

[0002] In stamping production lines, with the increasing automation of industrial production, in order to meet the high-quality and efficient processing of high-end equipment parts, more and more processes are integrated on the production line. Due to the layout of the production line, workpieces often need to be transferred between multiple parallel production lines, which requires the use of more efficient workpiece handling equipment between production lines.

[0003] In workpiece handling equipment, robotic arms that move in a two-dimensional plane have a significant advantage in handling speed compared to multi-axis robotic arms. Therefore, by arranging production lines in parallel and using two-dimensional robotic arms to handle materials between adjacent lines, production efficiency can be greatly improved.

[0004] Currently, two-dimensional planar robots include two types: serial robots and parallel robots. While serial robots can achieve a large range of motion through multiple links connected in series, the length and weight of the robot increase significantly with the number of links. This results in a greater torque load on each joint closer to the mounting end, making high-speed operation difficult despite the large range of motion. Furthermore, errors in joint position gradually accumulate towards the moving end of the robot during movement, and the rigidity of the serial mechanism decreases with increasing length, leading to lower motion accuracy at the robot's end effector. Parallel robots, as described in patent document CN112917458B, drive the end effector through two kinematic chains. While they offer significant advantages in rigidity and accuracy, the characteristics of the parallel structure limit the range of motion of the end effector. Additionally, the larger operating space of parallel mechanisms makes them prone to interference with metal molds and other components on the production line. Moreover, the motion sequence of some handling robots prevents high-speed workpiece transport, limiting the production line's cycle time. Summary of the Invention

[0005] To address the problem of low handling efficiency of current two-dimensional planar robots due to structural limitations, this invention provides a hybrid robot for workpiece handling that can operate at high speeds while having a larger range of motion.

[0006] To address the aforementioned problems, the present invention provides a hybrid robotic arm, comprising a connecting frame on which a sliding swing arm mechanism and two first linear drive mechanisms are mounted. The first linear drive mechanisms are symmetrically arranged on both sides of the sliding swing arm mechanism, each comprising a fixed part and a moving part. The fixed part is hinged to the connecting frame, and the moving part is hinged to the sliding swing arm mechanism. A linkage mechanism is mounted at the swing end of the sliding swing arm mechanism, comprising at least two rods connected in series via a revolute joint and / or a prismatic joint. One end of the linkage mechanism is hinged to the swing end of the sliding swing arm mechanism, and the other end is equipped with a material-grabbing actuator. The two first linear drive mechanisms form a parallel drive for the sliding swing arm mechanism, ensuring stable support for the overall mounting end of the robotic arm and improving the overall load-bearing capacity. The linkage mechanism at the end of the parallel module, acting as a series module, increases the robotic arm's operating range. The multiple joints in the parallel and series modules provide multiple redundant degrees of freedom for the robotic arm, making its movement more flexible, facilitating trajectory optimization, and enabling more efficient operation.

[0007] Preferably, the sliding rocker arm mechanism includes a rocker arm body and a slider. The slider is slidably mounted on the rocker arm body and can move freely along the rocker arm body. The slider is hinged to the middle of the connecting frame, and the hinge axis between the slider and the connecting frame is perpendicular to the length direction of the rocker arm body.

[0008] Preferably, the first linear drive mechanism includes a drive rod with lead screws mounted on it. The lead screw nuts are respectively hinged to both ends of the connecting frame, and the hinge axis between the lead screw nuts and the connecting frame is perpendicular to the length direction of the drive rod.

[0009] The first linear drive mechanism and the sliding rocker mechanism only have two motion forms: rotation and translation. The mechanism operates smoothly and is easy to control.

[0010] Preferably, the linkage mechanism includes a first rod and a second rod. A first drive motor is mounted on the first rod, and the motor shaft of the first drive motor is fixedly connected to the swing end of the sliding rocker mechanism. A second drive motor is provided at one end of the second rod, and the motor shaft of the second drive motor is fixedly connected to one end of the first rod. The material handling actuator is provided at the other end of the second rod.

[0011] Preferably, the linkage mechanism includes a mounting plate and a third rod. The swing end of the sliding rocker mechanism is provided with a third drive motor. The mounting plate is fixedly mounted on the motor shaft of the third drive motor. A second linear drive mechanism is provided on the mounting plate. One end of the third rod is hinged to the moving part of the second linear drive mechanism. The material handling actuator is located at the other end of the third rod.

[0012] The linkage mechanism has two structures: multi-link and telescopic swing type, which can be flexibly selected and used. Through the series mechanism, a greater range of motion can be obtained, and multiple redundant degrees of freedom are available, which facilitates trajectory planning and load optimization.

[0013] Preferably, the material handling actuator includes multiple material handling suction cups arranged in an array, which together form a gripping surface perpendicular to the movement plane of the robot arm. This facilitates the handling of plate-shaped workpieces on the stamping line.

[0014] Preferably, multiple suction cups are evenly distributed on both sides of the robot's motion plane. This makes the load on the robot nearly symmetrical with respect to the motion plane, reducing the bending moment experienced by the robot and improving its stability and motion accuracy.

[0015] Preferably, a through motor is installed at the end of the linkage mechanism, and the material handling actuator also includes two suction cup mounting brackets. Multiple material handling suction cups are evenly distributed on the two suction cup mounting brackets, which are respectively installed at both ends of the through motor. By mounting the material handling actuator with a rotating pair, the degree of freedom of the robot is increased, ensuring that the gripping plane remains horizontal at all times, which facilitates the optimization of the robot's trajectory.

[0016] On the other hand, the present invention also provides a trajectory planning method for the above-mentioned hybrid robotic arm, comprising the following steps:

[0017] S1. Determine the K key points P that the robotic arm's end effector needs to pass through. n ,n=1,2,3,...,K,P n The coordinates are (x n y n Each key point is located in the same plane, and the end path of the robot arm is obtained by interpolating the coordinates of multiple key points.

[0018] S2. Extract the end path points at equal intervals from the end path, and obtain the joint path points of each joint through the end path points;

[0019] S3. Obtain the joint path of each joint by interpolating the joint path points, and send the joint path to the controller to perform motion control on each joint of the robot.

[0020] Furthermore, in step S1, the expression for the terminal path is:

[0021]

[0022] Furthermore, step S2 includes:

[0023] S2-1. At regular time intervals... Extract and obtain A sequence of terminal path points M>K;

[0024] S2-2. Convert the Cartesian space coordinates of the robot's end effector path points to joint space coordinates to obtain the joint path point sequence. ,in, The number of joints, , For the first The inverse solution corresponding to the terminal path point is the th Joint path points of each joint.

[0025] Furthermore, step S2-2 includes:

[0026] S2-2-1. Take the sequence of angles between the forearm and the horizontal plane at each key point in step S1. and time series By interpolating using B-spline curves, the sequence of angles between the interpolated values ​​and the time intervals of the M terminal path points is obtained. , We obtain the angle of the rotation joint at the end of the robotic arm;

[0027] S2-2-2. Given the included angle value After assigning values ​​to the cascading motion joints, the joint path points of the remaining joints are accurately solved using an inverse kinematics model.

[0028] Furthermore, in step S2-2-2, the sum of the absolute values ​​of the differences between the angle values ​​of each joint at the current position and the angle values ​​of each joint at the previous position is minimized. The values ​​of the serially moving joints are iteratively optimized to obtain the optimal values ​​of the serially moving joints and the values ​​of the remaining non-redundant joints. The optimization objective is:

[0029]

[0030] In the formula, This represents the joint angle value at the current position. This is the joint angle value at the previous position; This represents the maximum position of each joint when the robotic arm reaches its farthest point during its work cycle. The weights for different joints.

[0031] Furthermore, in step S3, under the constraints of cycle time, joint velocities, acceleration, and driving capability, the time series is used. (in To optimize the variables, 5th-order B-spline curves were used to optimize the variables of each joint. Interpolation is performed on each joint path point, and the trajectory is optimized using a particle swarm optimization algorithm with the objective of minimizing the sum of the maximum impacts on each joint. .

[0032] As can be seen from the above technical solutions, the advantages of this invention are as follows: This robotic arm adopts a combination of parallel and series modules. While using parallel drive at the mounting end to ensure load-bearing capacity and rigidity, the linkage mechanism greatly improves the range of motion. The linkage mechanism has various structures, which can be flexibly selected according to material loading requirements. Moreover, the robotic arm as a whole has multiple redundant degrees of freedom, enabling more complex and flexible movements. Simultaneously, the movement of the robotic arm can be optimized and planned, optimizing the load on each joint to achieve faster and more flexible handling. Furthermore, the trajectory planning method provided by this invention, through precise calculation, can obtain the optimal movement trajectory of each joint of the robotic arm, greatly improving the operating speed of the robotic arm and thus improving online handling efficiency. Attached Figure Description

[0033] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0035] Figure 2 This is a schematic diagram of the parallel module in Embodiment 1 of the present invention.

[0036] Figure 3 This is a schematic diagram of the structure of the first linear drive mechanism in Embodiment 1 of the present invention.

[0037] Figure 4 This is a schematic diagram of the sliding rocker mechanism in Embodiment 1 of the present invention.

[0038] Figure 5 This is a schematic diagram of the linkage mechanism and material handling actuator in Embodiment 1 of the present invention.

[0039] Figure 6 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0040] Figure 7 This is a schematic diagram of the linkage mechanism and material handling actuator in Embodiment 2 of the present invention.

[0041] Figure 8 This is a schematic diagram of the motion state of Embodiment 1 of the present invention. Figure 1 .

[0042] Figure 9 This is a schematic diagram of the motion state of Embodiment 1 of the present invention. Figure 2 .

[0043] Figure 10This is a schematic diagram of the motion state of Embodiment 1 of the present invention. Figure 3 .

[0044] Figure 11 This is a flowchart of the particle swarm optimization algorithm in Embodiment 3 of the present invention.

[0045] In the diagram: 1. Connecting frame, 2. First linear drive mechanism, 2-1. Drive rod, 2-2. Lead screw, 3. Sliding rocker arm mechanism, 3-1. Rocker arm body, 3-2. Slider, 4. Linkage mechanism, 4-1. First rod, 4-2. Second rod, 4-3. Third rod, 4-4. Mounting plate, 5-1. First drive motor, 5-2. Second drive motor, 5-3. Third drive motor, 6. Material handling actuator, 6-1. Material handling suction cup, 6-2. Suction cup mounting bracket, 7. Through motor. Detailed Implementation

[0046] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0047] Example 1

[0048] like Figure 1 As shown, a hybrid robot includes a connecting frame 1, which serves as the mounting component for the robot and is installed at a designated position on the production line. A sliding swing arm mechanism 3 and two first linear drive mechanisms 2 are mounted on the connecting frame 1. The first linear drive mechanisms 2 are symmetrically arranged on both sides of the sliding swing arm mechanism 3. Each first linear drive mechanism 2 includes a fixed part and a moving part. The fixed part is hinged to the connecting frame 1, and the moving part is hinged to the sliding swing arm mechanism 3. The two first linear drive mechanisms 2 can drive the sliding swing arm mechanism 3 to swing and extend relative to the connecting frame 1 in a plane, forming the parallel part of the hybrid robot. A linkage mechanism 4 is mounted on the swing end of the sliding swing arm mechanism 3, forming the series part of the hybrid robot. A material handling actuator 6 is mounted on the end of the linkage mechanism via a revolute joint. Specifically:

[0049] like Figure 2 , 4 As shown, the sliding rocker arm mechanism includes a rocker arm body 3-1 and a slider 3-2. The slider 3-2 is slidably mounted on the rocker arm body 3-1 and can move freely along the rocker arm body 3-1. The slider 3-2 is hinged to the middle of the connecting frame 1. Figure 3As shown, the first linear drive mechanism includes a drive rod 2-1, on which a lead screw 2-2 is mounted. The lead screw nuts of the two lead screws 2-2 are respectively hinged to the two ends of the connecting frame 1. The hinge axis between the lead screw nuts and the connecting frame is perpendicular to the length direction of the drive rod 2-1. The hinge axis between the slider 3-2 and the connecting frame 1 is perpendicular to the length direction of the swing arm body 3-1, so that the drive rod 2-1 and the swing arm body 3-1 can move in a plane.

[0050] like Figure 5 As shown, the linkage mechanism includes a first rod 4-1 and a second rod 4-2. A first drive motor 5-1 is mounted on the first rod 4-1, and the motor shaft of the first drive motor 5-1 is fixedly connected to the swing end of the sliding rocker mechanism. A second drive motor 5-2 is provided at one end of the second rod 4-2, and the motor shaft of the second drive motor 5-2 is fixedly connected to one end of the first rod 4-1. A through motor 7 is mounted at the other end of the second rod 4-2. The material handling actuator 6 includes two suction cup mounting frames 6-2 and multiple material handling suction cups 6-1. The multiple material handling suction cups 6-1 are evenly arranged on the two suction cup mounting frames 6-2 and distributed in an array. The two suction cup mounting frames 6-2 are respectively mounted at both ends of the through motor 7, that is, on both sides of the motion plane of the hybrid manipulator. The multiple material handling suction cups 6-1 together form a gripping surface, which is perpendicular to the motion plane of the manipulator. Through the through motor 7, the gripping surface can always be kept horizontal.

[0051] like Figure 8-10 As shown, the hybrid robot has multiple redundant degrees of freedom, enabling it to perform large-amplitude, highly flexible movements within the motion plane, thus achieving efficient workpiece handling.

[0052] Example 2

[0053] In this embodiment, the parallel module of the hybrid robotic arm is the same as in Embodiment 1. The difference is that in this embodiment, the structure of the serial module, i.e., the linkage mechanism 4, is as follows: Figure 6 , 7 As shown, the device includes a mounting plate 4-4 and a third rod 4-3. A third drive motor 5-3 is provided at the swing end of the swing arm body 3-1. The mounting plate 4-4 is fixedly mounted on the motor shaft of the third drive motor 5-3. The third drive motor can drive the mounting plate 4-4 to rotate relative to the swing arm body 3-1. A second linear drive mechanism 4-5 is provided on the mounting plate 4-4. The second linear drive mechanism 4-5 can be driven by a synchronous belt. One end of the third rod 4-3 is fixedly mounted on the moving part of the second linear drive mechanism 4-5. The material handling actuator 6 is located at the other end of the third rod 4-3.

[0054] Example 3

[0055] Based on the hybrid robotic arms provided in Embodiments 1 and 2, the present invention also provides a trajectory planning method for the above-mentioned robotic arms, comprising the following steps:

[0056] S1. Determine the K key points P that the robotic arm's end effector needs to pass through. n ,n=1,2,3,...,K,P n The coordinates are (x n y n Each key point is located in the same plane, and the end path of the robot arm is obtained by interpolating the coordinates of multiple key points.

[0057] S2. Extract the end path points at equal intervals from the end path, and obtain the joint path points of each joint through the end path points;

[0058] S3. Obtain the joint path of each joint by interpolating the joint path points, and send the joint path to the controller to perform motion control on each joint of the robot.

[0059] Step S1 is as follows:

[0060] S1-1. Locate the K key points in the plane. Separation in two directions, in time With xk as the independent variable and yk as the dependent variable, interpolation is performed to obtain functions of the position in the X and Y directions as a function of time. , When performing interpolation, a fifth-order B-spline curve is used to ensure that the acceleration and jerk have continuous and smooth curves, guaranteeing a smooth and reasonable path without abrupt changes. Based on the key points, node vectors, and basis functions, the control vertices of the B-spline curve are calculated inversely, and then the B-spline curve is plotted using these control vertices.

[0061] S1-1-1: The expression for the B-spline curve is as follows: (In the formula, These are the key points, i.e., the aforementioned critical points; To control the vertices, For node vectors; (For B-spline basis functions)

[0062] S1-1-2: B-spline curve The expression for the first derivative is:

[0063]

[0064]

[0065] In the formula, , , .

[0066] S1-1-3: When calculating the control vertices, the type points and node vectors are needed. The cumulative chord length parameterization method is used to normalize the time nodes to obtain the values ​​of the node vectors.

[0067]

[0068] This leads to the B-spline basis functions. :

[0069]

[0070] S1-1-4: +1 type value point can construct A 5th-order B-spline curve is needed. Five control points are used to control the curve shape. (For solving...) +5 control points need to be constructed Solve the equation with +5. Assume the sequence of joint path points of the robotic arm is... The starting time is The termination time is , No. A segment of a 5th-order B-spline curve can be represented as:

[0071]

[0072] Given the positions of the endpoints of each curve segment, and based on the requirement of continuity, the endpoints of two consecutive B-spline curve segments must satisfy the following conditions to form a continuous curve. -1 equation; since the motion at the initial and final positions is known, the start and stop speeds are specified as... , Start-stop acceleration , To allow for the addition of 6 equations, a total of +5 equations can be solved +5 control vertices Given the node vectors, basis functions, and control vertices, the equation of the B-spline curve can be solved.

[0073]

[0074]

[0075] S1-1-5: The velocity of a 5th-order B-spline curve can be obtained from the derivative of the B-spline curve. acceleration and accelerometer As shown in the following formula:

[0076]

[0077]

[0078]

[0079] The trajectories of each joint must satisfy the following kinematic constraints:

[0080]

[0081] In the formula, Indicates the joint number; , , These are the maximum speed, maximum acceleration, and maximum jerk of the joint movement, respectively.

[0082] S1-1-6: B-spline curves have convex hull properties, and the kinematic constraints of each joint can be transformed into control vertex constraints of the spline curve. Therefore, the control vertices need to satisfy the following conditions:

[0083]

[0084] In the formula, Indicates the joint number; The first curve representing the joint velocity, acceleration, and jerk curves One control vertex;

[0085] During the fixed operating cycle of the robotic arm Within, in time series (in ) is the optimization variable, which is then optimized using the particle swarm optimization algorithm to achieve the desired result. X and Y The directional acceleration is minimized, i.e., the impact is minimized:

[0086] For this optimization problem, the optimization variable is a time series: The objective function is optimized as follows:

[0087]

[0088] In the formula, and These are the weighting coefficients; and for X and Y directional acceleration;

[0089] Considering the runtime requirements to satisfy time, velocity, and acceleration constraints, the constraint expressions are as follows:

[0090] st

[0091] In the formula, Indicates the first The key point and the first +1 time interval between key points: ; The sum of the time intervals represents the running period. ; , , and They are respectively X and Y Velocity and acceleration in the direction; , , and They are respectively X and Y The maximum permissible speed and maximum acceleration in the direction.

[0092] Through the above steps, the expression for the terminal path is obtained:

[0093]

[0094] Step S2 includes:

[0095] S2-1: At certain time intervals... Extract and obtain A sequence of terminal path points The number of path points M is greater than the number of key points K in S1;

[0096] S2-2: Convert the Cartesian space coordinates of the robot's end effector path points to joint space coordinates to obtain the joint path point sequence. ,in, The number of joints, , For the first The inverse solution corresponding to the terminal path point is the th Joint path points of each joint:

[0097] This hybrid robotic arm requires 3 degrees of freedom to move in a plane. The robot itself has 5 degrees of freedom, with 2 redundant degrees. Given the angle between the forearm and the horizontal plane, inverse kinematics modeling is performed using robot coordinate transformation and the closed-loop vector method. Since the robotic arm is redundant and multiple solutions exist, an approach of assigning joints, precise solution, and iterative optimization is used to solve the inverse kinematics.

[0098] S2-2-1: Take the sequence of angles between the forearm and the horizontal plane at each key point in step S1. (The included angle value is manually defined by the operator based on experience) and time series. By interpolating using a quintic B-spline curve, the sequence of angles between the interpolated values ​​and the time intervals of the M terminal path points is obtained. , The workpiece remains horizontal during the operation of the robotic arm, resulting in smoother operation. Therefore, the angle between the forearm and the horizontal plane is known. Then, the angle of the robotic arm's end joint is obtained, which is the angle of the third drive motor;

[0099] S2-2-2: Given the included angle value After assigning values ​​to the cascading motion joints, the joint path points of the remaining joints are accurately solved using an inverse kinematics model. Specifically, the cascading motion joint values ​​are iteratively optimized by minimizing the sum of the absolute values ​​of the differences between the angle values ​​of each joint at the current position and the angle values ​​of each joint at the previous position, to obtain the optimal cascading motion joint values ​​and the values ​​of the remaining non-redundant joints. The optimization objectives are as follows:

[0100]

[0101] In the formula, This represents the joint angle value at the current position. This is the joint angle value at the previous position; The maximum values ​​of each joint position when the robot arm reaches its farthest point during its work cycle are obtained through measurement and analysis by the operator. The weights for different joints.

[0102] Step S3 includes: under the constraints of cycle time, joint velocities, acceleration, and driving capability, using a time series... (in To optimize the variables, 5th-order B-spline curves were used to optimize the variables of each joint. Interpolation is performed on each joint path point, and the trajectory is optimized using a particle swarm optimization algorithm with the objective of minimizing the sum of the maximum impacts on each joint. Specifically:

[0103] The optimization variable is a time series: The objective function expression is optimized as follows:

[0104]

[0105] In the formula, Indicates the first The impact on each joint can be solved by taking the third derivative of the B-spline curve, i.e. ;

[0106] When a robotic arm performs material handling tasks, it must meet the limitations of the driving joints' own operational capabilities to ensure stable operation of each joint over a long period. The constraint expressions are as follows:

[0107]

[0108] In the formula, For the first robotic arm joint; Indicates the first The key point and the first +1 time interval between key points: ; , , The first The expressions for the position, velocity, and acceleration of each joint can be obtained by differentiating the B-spline curve; For the first The joint torque of each joint can be obtained through a dynamic model.

[0109] The specific process of the particle swarm optimization algorithm is as follows: Figure 11 As shown: First, determine the initial parameters of the particle swarm optimization algorithm, and set them with respect to t. i The type value points and node vectors are then used to construct the vectors about t. i The fifth-order B-spline curve and its derivatives are used to set constraints and an objective function. The velocity and position of the particles are initialized, and then the particle fitness is calculated. The particle with the best individual fitness value is obtained, and then the particle with the best global fitness value is obtained. The position and velocity of the particles are then updated sequentially, and the iteration is checked to determine whether it has ended.

[0110] If the process is not completed, the particle fitness will be re-selected.

[0111] If it ends, then obtain the optimal time interval series {t}. i Then, solve for the fifth-order B-spline function and its derivatives, outputting graphs of the spline curve's position, velocity, and acceleration over time, and determining whether the solution meets the requirements.

[0112] If satisfied, the solution is complete;

[0113] If not satisfied, reset the settings for t. i The type value points and node vectors are then recalculated.

[0114] As can be seen from the above embodiments, the beneficial effects of this invention are as follows: This robotic arm adopts a combination of parallel and series modules. While using parallel drive at the mounting end to ensure load-bearing capacity and rigidity, it greatly improves the range of motion by utilizing a linkage mechanism. The linkage mechanism has various structures that can be flexibly selected according to material loading requirements. Moreover, the robotic arm as a whole has multiple redundant degrees of freedom, enabling more complex and flexible movements. At the same time, it can optimize and plan the movement of the robotic arm, optimize the load of each joint, and achieve faster and more flexible handling. In addition, the trajectory planning method provided by this invention can obtain the optimal movement trajectory of each joint of the robotic arm through precise calculation, greatly improving the operating speed of the robotic arm and thus improving the efficiency of online handling.

[0115] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hybrid robotic arm, comprising a connecting frame (1), characterized in that, The connecting frame (1) is equipped with a sliding rocker arm mechanism (3) and two first linear drive mechanisms (2). The first linear drive mechanisms (2) are symmetrically arranged on both sides of the sliding rocker arm mechanism (3). The first linear drive mechanism (2) includes a fixed part and a moving part. The fixed part is hinged to the connecting frame (1), and the moving part is hinged to the sliding rocker arm mechanism (3). The swing end of the sliding rocker mechanism (3) is equipped with a linkage mechanism. The linkage mechanism includes at least two rods connected in series by a rotary joint and / or a sliding joint. One end of the linkage mechanism is hinged to the swing end of the sliding rocker mechanism, and the other end of the linkage mechanism is equipped with a material handling actuator (6). The sliding rocker arm mechanism includes a rocker arm body (3-1) and a slider (3-2). The slider (3-2) is slidably mounted on the rocker arm body (3-1) and can move freely along the rocker arm body (3-1). The slider (3-2) is hinged to the middle of the connecting frame (1). The hinge axis between the slider (3-2) and the connecting frame (1) is perpendicular to the length direction of the rocker arm body (3-1). The first linear drive mechanism includes a drive rod (2-1), on which a lead screw (2-2) is mounted. The lead screw nuts of the two lead screws (2-2) are respectively hinged to the two ends of the connecting frame (1). The hinge axis between the lead screw nuts and the connecting frame is perpendicular to the length direction of the drive rod (2-1). The linkage mechanism includes a first rod (4-1) and a second rod (4-2). A first drive motor (5-1) is mounted on the first rod (4-1), and the motor shaft of the first drive motor (5-1) is fixedly connected to the swing end of the sliding rocker mechanism. A second drive motor (5-2) is provided at one end of the second rod (4-2), and the motor shaft of the second drive motor (5-2) is fixedly connected to one end of the first rod (4-1). The material handling actuator is located at the other end of the second rod (4-2). Alternatively, the linkage mechanism includes a mounting plate (4-4) and a third rod (4-3). The swing end of the sliding rocker mechanism (3) is provided with a third drive motor (5-3). The mounting plate (4-4) is fixedly mounted on the motor shaft of the third drive motor (5-3). A second linear drive mechanism (4-5) is provided on the mounting plate (4-4). One end of the third rod (4-3) is hinged to the moving part of the second linear drive mechanism (4-5). The material handling actuator is located at the other end of the third rod (4-3).

2. The hybrid robotic arm according to claim 1, characterized in that, The material handling actuator (6) includes multiple material handling suction cups (6-1), which are arranged in an array. The multiple material handling suction cups (6-1) together form a gripping surface, which is perpendicular to the motion plane of the robot arm.

3. The hybrid robotic arm according to claim 2, characterized in that, Multiple material-grabbing suction cups are evenly arranged on both sides of the robot's motion plane.

4. The hybrid robotic arm according to claim 2, characterized in that, The linkage mechanism is equipped with a through motor (7) at its end. The material handling actuator (6) also includes two suction cup mounting brackets (6-2). Multiple material handling suction cups (6-1) are evenly arranged on the two suction cup mounting brackets (6-2). The two suction cup mounting brackets (6-2) are respectively installed at both ends of the through motor (7).

5. A trajectory planning method for a hybrid robotic arm according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Determine the K key points P that the robotic arm's end effector needs to pass through. n ,n=1,2,3,...,K,P n The coordinates are (x n y n Each key point is located in the same plane, and the end path of the robot arm is obtained by interpolating the coordinates of multiple key points. S2. Extract the end path points at equal intervals from the end path, and obtain the joint path points of each joint through the end path points; S3. Obtain the joint path of each joint by interpolating the joint path points, and send the joint path to the controller to perform motion control on each joint of the robot.

6. The robotic arm trajectory planning method according to claim 5, characterized in that, In step S1, the expression for the terminal path is: ； In the formula, t represents time.

7. The robotic arm trajectory planning method according to claim 6, characterized in that, Step S2 includes: S2-1. At certain time intervals... Extract and obtain A sequence of terminal path points M>K; S2-2. Convert the Cartesian space coordinates of the robot's end effector path points to joint space coordinates to obtain the joint path point sequence. ,in, The number of joints, , For the first The inverse solution corresponding to the terminal path point is the th... Joint path points of each joint.

8. The robotic arm trajectory planning method according to claim 7, characterized in that, Step S2-2 includes: S2-2-1. Take the sequence of angles between the forearm and the horizontal plane at each key point in step S1. and time series By interpolating using B-spline curves, the sequence of angles between the interpolated values ​​and the time intervals of the M terminal path points is obtained. , We obtain the angle of the rotation joint at the end of the robotic arm; S2-2-2. Given the included angle value After assigning values ​​to the cascading motion joints, the joint path points of the remaining joints are accurately solved using an inverse kinematics model.

9. The robotic arm trajectory planning method according to claim 8, characterized in that, In step S2-2-2, the sum of the absolute values ​​of the differences between the angle values ​​of each joint at the current position and the angle values ​​of each joint at the previous position is minimized. The values ​​of the serially moving joints are iteratively optimized to obtain the optimal values ​​of the serially moving joints and the values ​​of the remaining non-redundant joints. The optimization objective is: In the formula, This represents the joint angle value at the current position. This is the joint angle value at the previous position; This represents the maximum position of each joint when the robotic arm reaches its farthest point during its work cycle. The weights for different joints.

10. The robotic arm trajectory planning method according to claim 9, characterized in that, In step S3, under the constraints of cycle time, joint velocities, acceleration, and driving capability, the time series is used. ,in To optimize the variables, 5th-order B-spline curves were used to optimize the variables of each joint. Interpolation is performed on each joint path point, and the trajectory is optimized using a particle swarm optimization algorithm with the objective of minimizing the sum of the maximum impacts on each joint. .

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