CN111758352A - Optimal track design method for transplanting robot actuating mechanism - Google Patents

Optimal track design method for transplanting robot actuating mechanism Download PDF

Info

Publication number
CN111758352A
CN111758352A CN202010830538.0A CN202010830538A CN111758352A CN 111758352 A CN111758352 A CN 111758352A CN 202010830538 A CN202010830538 A CN 202010830538A CN 111758352 A CN111758352 A CN 111758352A
Authority
CN
China
Prior art keywords
connecting rod
robot
hinged
transplanting
ball screw
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010830538.0A
Other languages
Chinese (zh)
Inventor
唐玉新
王士林
陆岱鹏
徐陶
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu Academy of Agricultural Sciences
Original Assignee
Jiangsu Academy of Agricultural Sciences
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiangsu Academy of Agricultural Sciences filed Critical Jiangsu Academy of Agricultural Sciences
Priority to CN202010830538.0A priority Critical patent/CN111758352A/en
Publication of CN111758352A publication Critical patent/CN111758352A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01C—PLANTING; SOWING; FERTILISING
    • A01C11/00—Transplanting machines
    • A01C11/02—Transplanting machines for seedlings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J11/00—Manipulators not otherwise provided for
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/16—Programme controls
    • B25J9/1656—Programme controls characterised by programming, planning systems for manipulators
    • B25J9/1664—Programme controls characterised by programming, planning systems for manipulators characterised by motion, path, trajectory planning
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/17—Mechanical parametric or variational design
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2111/00—Details relating to CAD techniques
    • G06F2111/04—Constraint-based CAD

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Geometry (AREA)
  • General Physics & Mathematics (AREA)
  • Robotics (AREA)
  • Mechanical Engineering (AREA)
  • Computer Hardware Design (AREA)
  • Evolutionary Computation (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental Sciences (AREA)
  • Soil Sciences (AREA)
  • Computational Mathematics (AREA)
  • Mathematical Analysis (AREA)
  • Mathematical Optimization (AREA)
  • Pure & Applied Mathematics (AREA)
  • Manipulator (AREA)

Abstract

The invention provides a method for designing an optimal track of a transplanting robot actuating mechanism, wherein the transplanting robot comprises the following components: the device comprises a rack, two-dimensional translation parallel mechanisms, a one-dimensional folding mechanism and a belt type conveying mechanism; the first servo motor is arranged at the top of the rack, and the two-dimensional translation parallel mechanisms are positioned on two independent Z-X planes through the ball screw mechanism; through the optimal design of the transplanting robot, the transplanted plants are evenly spaced, the field transplanting efficiency is effectively improved, and the labor and the time are saved.

Description

Optimal track design method for transplanting robot actuating mechanism
Technical Field
The application relates to the field of intelligent robots, in particular to an optimal track design method for a transplanting robot executing mechanism.
Background
Transplanting is an agricultural activity in which prepared seedlings are transplanted from a seedbed, a tray, onto a growth tray in a greenhouse, or onto a field prepared seedbed. In vegetable and horticultural production, manual transplanting of pot seedlings is labor intensive, time consuming, and sometimes results in uneven spacing between plants, a labor intensive, time consuming, and precision demanding activity. Because the manual operation is inconvenient and the precision is required in the seedling transplanting process, mechanized transplanting machines such as automation machines and devices are developed to solve the problems. Under the current situation, the production capacity of the automatic transplanter and the transplanter is low, and most of the automatic transplanter and the transplanter are suitable for greenhouse operation. That is to say that transplanting efficiency is lower for transplanting the robot, can not satisfy the demand, and most transplanting robot can only work in the greenhouse. In addition, in the transplanting process, the transplanting robot vibrates due to inaccurate design, and inaccurate movement may occur, so that the conditions of seedling injury and seedling clamping are caused.
Disclosure of Invention
The invention provides an optimal track design method of a transplanting robot actuating mechanism, which enables transplanted plants to be uniformly spaced through the optimal design of a transplanting robot, effectively improves the field transplanting efficiency and saves labor and time.
A method for designing an optimal trajectory of a transfer robot actuator, wherein the transfer robot comprises:
the device comprises a rack, two-dimensional translation parallel mechanisms, a one-dimensional folding mechanism and a belt type conveying mechanism;
the first servo motor is arranged at the top of the rack, and the two-dimensional translation parallel mechanisms are positioned on two independent Z-X planes through the ball screw mechanism;
the two-dimensional translation parallel mechanism comprises a fixed plate, a ball screw nut, a servo motor spline shaft fixing seat, an outer driving connecting rod, an inner driving connecting rod, an outer driven connecting rod, an inner driven connecting rod, a moving platform and a triangular connecting frame; the ball screw nut and the servo motor spline shaft fixing seat are arranged on the fixing plate, and a through hole is formed in the outer side position of the ball screw nut; one end of the outer driving connecting rod is hinged to the fixing plate, the other end of the outer driving connecting rod is hinged to the triangular connecting frame, one end of the inner driving connecting rod is hinged to the fixing plate, the other end of the inner driving connecting rod is hinged to the triangular connecting frame, one end of the inner driven connecting rod is hinged to the triangular connecting frame, the other end of the inner driven connecting rod is hinged to the inner side area of the moving platform, one end of the outer driven connecting rod is hinged to the triangular connecting frame, the other end of the outer driven connecting rod is hinged to the outer side area of the moving platform, the second; the guide rail passes through the through hole; the first servo motor drives the lead screw to be in threaded connection with the ball screw nut.
The one-dimensional folding mechanism comprises a plurality of rectangular frames, a plurality of first connecting rods, a plurality of second connecting rods and a plurality of grabbing mechanisms, wherein the grabbing mechanisms are arranged at the bottoms of the rectangular frames; each rectangular frame is provided with a sliding chute, the middle parts of a first connecting rod and a second connecting rod are hinged, one end of the first connecting rod is hinged to the bottom of the rectangular frame, and one end of the second connecting rod is hinged to the bottom of the adjacent rectangular frame; the other end of the first connecting rod is hinged with one end of the adjacent second connecting rod through a hinge shaft, and bulges are arranged on two sides of the hinge shaft and slide in the upper sliding groove of the rectangular frame; the rectangular frames on the two outermost sides are provided with mounting plates which are fixedly connected with the moving platform.
When the two-dimensional translation parallel mechanism works, the spline shafts of the two second servo motors are used for mechanically synchronizing the motion of the end effectors of the two-dimensional translation parallel mechanism; the two-way ball screw with opposite threads on the left side and the right side, which is driven by the first servo motor, translates the two-dimensional translation parallel mechanism which is symmetrically arranged on the Y axis to enable the two-dimensional translation parallel mechanism to approach or separate from each other; fixing the mounting plate of the one-dimensional folding mechanism on a moving platform of the two-dimensional translation parallel mechanism to serve as a grabbing mechanism of the transplanting robot; conveying the pot seedlings to a proper grabbing position through a belt type conveying mechanism; the gripping mechanism grips, transfers and releases the pot seedlings from the conveying belt.
According to the optimal track design method of the transplanting robot actuating mechanism, through the structural design of the rack, the two-dimensional translation parallel mechanism and the one-dimensional folding mechanism of the transplanting robot and the reasonable planning of the working space analysis and the track planning, compared with other pot seedling transplanting robots, the angular velocity and the acceleration of the transplanting robot are zero at the starting point and the end point of each track, the curves of the angular displacement, the angular velocity and the angular acceleration of the two active connecting rods are smooth and continuous, the dynamic wear, vibration, noise and stress of a robot driver are greatly reduced, the service life is prolonged, the transplanted plants are uniformly spaced, the field transplanting efficiency is effectively improved, and the labor and the time are saved.
Drawings
Fig. 1 is a schematic structural view of a transfer robot of the present invention.
Fig. 2 is a schematic structural view of a two-dimensional translation parallel mechanism of the transplanting robot of the present invention.
Fig. 3 is a schematic structural view of a one-dimensional folding mechanism of the transplanting robot of the present invention.
Fig. 4 is a schematic view of a kinematic model of a two-dimensional translational parallel mechanism of the transplanting robot of the present invention.
Fig. 5 is a schematic view of a pot seedling transplanting process of the transplanting robot of the present invention.
Reference numerals: the seedling pot seedling,
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
The invention provides an optimal track design method of a transplanting robot actuating mechanism, which enables transplanted plants to be uniformly spaced through the optimal design of a transplanting robot, effectively improves the field transplanting efficiency and saves labor and time.
A method for designing an optimal trajectory of a transfer robot actuator, wherein the transfer robot comprises:
the device comprises a frame 1, two-dimensional translation parallel mechanisms 2, a one-dimensional folding mechanism 3 and a belt type conveying mechanism 4;
the first servo motor 5 is arranged at the top of the rack 1, and the two-dimensional translation parallel mechanisms 2 are positioned on two independent Z-X planes through the ball screw mechanism 6;
as shown in fig. 2, the two-dimensional translation parallel mechanism 2 comprises a fixed plate 10, a ball screw nut 11, a servo motor spline shaft fixing seat 12, an outer driving connecting rod 13, an inner driving connecting rod 14, an outer driven connecting rod 15, an inner driven connecting rod 16, a moving platform 17 and a triangular connecting frame 18; the ball screw nut 11 and the servo motor spline shaft fixing seat 12 are arranged on the fixing plate 10, and a through hole 18 is formed in the outer side position of the ball screw nut 11; one end of an outer driving connecting rod 13 is hinged to the fixing plate 10, the other end of the outer driving connecting rod is hinged to the triangular connecting frame 18, one end of an inner driving connecting rod 14 is hinged to the fixing plate 10, the other end of the inner driving connecting rod is hinged to the triangular connecting frame 18, one end of an inner driven connecting rod 16 is hinged to the triangular connecting frame 18, the other end of the inner driven connecting rod is hinged to the inner side area of the moving platform 17, one end of an outer driven connecting rod 15 is hinged to the triangular connecting frame 18, the other end of the outer driven connecting rod is hinged to the outer side area of the moving platform 17, a second servo motor 19; the guide rail 7 passes through the through hole 18; the first servomotor 5 drives a screw threaded connection to the ball screw nut 11.
As shown in fig. 3, the one-dimensional folding mechanism 3 includes a plurality of rectangular frames 20, a plurality of first links 21 and a plurality of second links 22, and a plurality of grasping mechanisms 23, wherein the grasping mechanisms 23 are provided at the bottom of the rectangular frames 20; each rectangular frame 20 is provided with a sliding chute 24, the middle parts of a first connecting rod 21 and a second connecting rod 22 are hinged, one end of the first connecting rod 21 is hinged at the bottom of the rectangular frame 20, and one end of the second connecting rod 22 is hinged at the bottom of the adjacent rectangular frame 20; the other end of the first connecting rod 21 is hinged with one end of the adjacent second connecting rod 22 through a hinge shaft 25, two sides of the hinge shaft are provided with bulges 25, and the bulges 25 slide in an upper sliding groove 24 of the rectangular frame 20; the rectangular frames 20 at the two outermost sides are provided with mounting plates 26, and the mounting plates 26 are fixedly connected with the moving platform 17.
When the two-dimensional translation parallel mechanism 2 works, the spline shafts of the two second servo motors 19 are used for mechanically synchronizing the motion of the end effectors of the two-dimensional translation parallel mechanism 2; the two-way ball screw shafts with opposite threads on the left side and the right side, which are driven by the first servo motor 5, translate the two-dimensional translation parallel mechanism 2 which is symmetrically arranged on the Y axis to enable the two-dimensional translation parallel mechanism to approach or separate from each other; fixing the mounting plate 26 of the one-dimensional folding mechanism on the moving platform 17 of the two-dimensional translation parallel mechanism 2 to serve as a grabbing mechanism of the transplanting robot; conveying the pot seedlings to a proper grabbing position through a belt type conveying mechanism 4; the gripping mechanism grips, transfers and releases the pot seedlings from the conveying belt.
In order to realize high-speed transplanting of pot seedlings, two identical translation parallel devices are adopted. Each device consists of a fixed platform, a mobile platform and two identical kinematic chains, as shown in fig. 2. Each kinematic chain comprises two sets of parallelogram linkages, namely an active inner linkage and a passive outer linkage, connected by a revolute joint. This configuration allows for static and dynamic stiffness in the direction perpendicular to the plane of motion. The stiffness is sufficient to support the reaction forces generated by the one-dimensional folding mechanism perpendicular to the plane of motion of the parallel device. The one-dimensional foldable mechanism can grab seedlings of a plurality of flowerpots in one tray at the same time.
The biplanar foldable scissors mechanism shown in fig. 3 is connected by a multi-rectangular frame with revolute joints and sliding grooves. The rectangular frame is used for increasing the rigidity of the shearing mechanism and keeping the fixing direction of the clamp. This scissor mechanism maintains equal spacing between the pincers from the unfolded to the folded seedling. Thus, it allows proper spacing when picking up seedlings from the tray and transplanting the seedlings in the field. Therefore, this scissor mechanism allows the seedlings transplanted from the flowerpot seedlings in a row to be used as a clamp from the tray to the field. The spacing between pot seedlings in the seedling tray is 5-10cm, and the growth field is 30-90 cm.
As shown in fig. 2, the parallelogram linkage has equal lengths of the outer and inner active links and equal lengths of the outer and inner passive links, simplifying the kinematic model of the translational parallel device into a 5-bar plane link as shown in fig. 4. The position vector q of point P on the motion platform relative to coordinate system OXZ is as follows:
Figure BDA0002635875740000051
wherein q is [ x z ]]T，
Figure BDA0002635875740000052
When i is 1, sgn (i) is 1, when i is 2, sgn (i) is-1, d is the offset distance between O and Ai, and L is1And L2Is the length of the active and passive links, viAnd wiIs the velocity of the active and passive links, where vi＝[cosθ1isinθ1i]T，wi＝[cosθ2isinθ2i]T，θ1iAnd theta2iIs the position angle of the active and passive links, as shown in FIG. 4, the transmission angle βiIs the angle between the active and passive links.
For inverse kinematics, the position x, z of the moving platform is known, and the active angle θ is known11And theta12Can be calculated. By equation (1), the kinematic equation can be given as:
Figure BDA0002635875740000053
wherein M isi＝-2L1z，Ni＝-2L1(x-sgn(i)d)；
Figure BDA0002635875740000054
Design parameters and acute angles βiCan be expressed as:
Figure BDA0002635875740000055
and the active joint angular velocity vector of the parallel robot is related to the linear velocity vector of the end effector by the matrix. The speed relationship is as follows:
Figure BDA0002635875740000056
wherein the content of the first and second substances,
Figure BDA0002635875740000057
the speed mapping function is of the form:
Figure BDA0002635875740000058
wherein the content of the first and second substances,
Figure BDA0002635875740000059
the transformation matrix is:
Figure BDA0002635875740000061
the linear velocity of the gripper mechanism in the Y direction is related to the angular velocity of the servo motor driving the bidirectional ball screw as follows:
v＝ny (6)
where v is the linear velocity of the grasping mechanism, n is the angular velocity of the lead screw, and y is the linear distance traversed by the grasping mechanism.
The transplanting robot of the invention does not take out and transplant seedlings in the main working process, and expects a working space WtB and h, respectively. From the formula (1), when the position of the mobile platform is given, the two-dimensional translation robot can be represented by L1、L2And d. Given the design parameters, the reachable workspace of the robot may be determined, with the desired workspace being a subset of the reachable workspace of the robot. Therefore, another design parameter H is introduced to describe the upper boundary of the desired workspace in the Z-direction as shown in FIG. 4. The constraints comprise geometric constraints and kinematic constraints, and for the two-dimensional translation parallel device, the constraint relation is as follows:
Figure BDA0002635875740000062
where it is a factor representing the size of the desired workspace relative to the size of the robot. When becoming large, the operability of the robot eventually decreases. Otherwise, if it becomes smaller, the robot volume is larger than the desired workspace. For pot seedlings, transplanting and taking out are set in the range of 0.7-1.2.
In addition, in order to have enough space for mounting two servo motors on the frame of the transplanting robot, it is necessary to satisfy:
d≥dmax＝0.100m (8)
in order to avoid singularities in the whole working space and with a favourable force transmission during the operation of the transplanting robot, kinematic constraints also need to be considered, the inequality constraints being:
(L1 2+L2 2-2L1L2cos[β])-H2≤0 (9)
(b/2+e)2+(H+h)2-(L1 2+L2 2-2L1L2cos[β])≤0 (10)
through experiments, beta is set to be more than or equal to 35 and less than 180, so that the force transmission is facilitated and the singularity is avoided.
Since the transplanting robot is designed to operate at high speed with high accuracy and high rigidity during its operation, the following can be used in the overall compression performance index η:
Figure BDA0002635875740000071
wherein
Figure BDA0002635875740000072
Is the index of the global operational performance (p-i-p),
Figure BDA0002635875740000073
is a condition of wηIs that
Figure BDA0002635875740000074
The factor of (2). However, it is preferable that, in the case of,
Figure BDA0002635875740000075
and
Figure BDA0002635875740000076
is a function of k, k beingCondition number of jacobian matrix. For better performance of the manipulator, 1/k is 0.5 ≦ 1/k ≦ 1. Therefore, the size of the pot seedling transplanting robot can be obtained by optimizing the formula (11) given the constraint conditions.
η(X)→min，X∈R4(12)
Wherein X is (L)1L2d H)TRepresenting the design parameters.
In the size synthesis, the pot seedling tray is considered to have a height of 100mm and less. The task work space Wt is considered as a rectangle with a width b of 760mm and a height h of 600mm to match the size of a standard pot seedling tray and the level between the pick point and the planting point. Other constraints considered during the analysis are set as follows: d is more than or equal to 100 and less than or equal to 120, wη1, β -45 the optimal dimensional synthesis is considered to minimize the constrained cost function given in (11)1＝400mm，L2＝921mm，d＝120mm，H＝788mm.
Workspace analysis is important for investigating workspace utilization. The workspace may be determined by direct or reverse motion using a parallel mechanism. Since the direct kinematics of the parallel robot under study are complex. Thus, a reverse motion solution is used to create the reachable workspace of the robot. For the inverse kinematics solution present in (2),
Figure BDA0002635875740000077
the condition should hold when i is 1, 2. Using this condition with the optimal geometry of the robot, MATLAB based algorithms were developed to generate the reachable workspace of the manipulator.
In a complete cycle of pot seedling transplanting, the robot goes through three motion stages; namely a seedling taking stage, a seedling transplanting stage and a seedling returning stage. In the seedling taking stage, the robot moves its end effector horizontally from P0 to P1, then down in the Z-X plane from P1 to P2, at P2 the robot picks up the seedlings and then begins the transplanting stage. At this stage, the robot moves its end effector gripping the seedling up from P2 to P1, then from P1 to P3 in N Z-X planes; when at P3, the two manipulators underwent another motion in the Z-Y plane from the Y direction to P4 before moving downward in the Z-X plane to release the seedlings at P5 (on the ground in an open field) for planting. Finally, the robot returns its end effector from P5 to the original position of P0 via P4 and P3. The flow of the desired path of the transplanting cycle can be described as P0-P1-P2-P1-P3-P4-P5-P4-P3-P0. Fig. 5 shows the pot seedling transplanting process in a transplanting robot work cycle.
To ensure motion stability and good performance of the manipulator, the velocity and acceleration are set equal to zero at the beginning and end of each trajectory. Furthermore, the velocity and acceleration should be continuous. Based on these requirements, a fifth order polynomial was chosen as the operating principle of the manipulator with six constraints listed
Figure BDA0002635875740000081
Figure BDA0002635875740000082
Wherein q is0And q isfIs the angular position of the active link or the displacement of the end effector, t0And tfIs the time at the beginning and end of the trajectory of the transplanting robot. The general equation for the law of motion is expressed as:
q(t)＝a0+a|1t+a2t2+a3t3+a4t4+a5t5(14)
Figure BDA0002635875740000083
Figure BDA0002635875740000084
wherein a isi1,2, 3, 4, 5 are coefficients of the law of motion equation. QT and QT are velocity and acceleration, respectively. Using equations (14), (c), (d), (15) And (16) formulating six simultaneous equations. Solving the equation to obtain the coefficients of the motion law equation as follows:
a0＝q0，a1＝0，a2＝0，
Figure BDA0002635875740000085
in the transplanting process, inaccurate movement may occur mainly due to vibration, which causes seedling damage and seedling clamping. Acceleration is the dominant factor causing vibration, and it is therefore useful to define a trajectory that satisfies a given constraint of maximum acceleration. The maximum acceleration can be found by solving a quadratic equation and is expressed as:
Figure BDA0002635875740000086
simulation results for determining the manipulator workspace indicate that the achievable workspace is formed by the difference between the area bounded by the intersection of two large consecutive arcs and the area bounded by the union of two small consecutive arcs, which are symmetrical in the Z-X plane, and that the desired workspace is within the boundaries of the achievable workspace of the manipulator.
The speed and acceleration of the transplanting robot in the Z, X and Y directions are time-continuous functions and equal to zero at the beginning and end of each trajectory, calculated according to the constraints of the above equation. The maximum acceleration of the robot Z, X, Y direction is 43.33m/s during transplanting2、44.10m/s2、45.00m/s2The maximum speeds of X, Z and Y were 4.45m/s, 4.68m/s and 6.75m/s, respectively. The results show that the vibration of the working cycle of the transplanting robot is kept at a good level, the transplanting performance of the seedlings is improved, and the time taken for the transplanting robot to complete the transplanting cycle is 1.8 seconds.
According to the optimal track design method of the transplanting robot actuating mechanism, through the structural design of the rack, the two-dimensional translation parallel mechanism and the one-dimensional folding mechanism of the transplanting robot and the reasonable planning of the working space analysis and the track planning, compared with other pot seedling transplanting robots, the angular velocity and the acceleration of the transplanting robot are zero at the starting point and the end point of each track, the curves of the angular displacement, the angular velocity and the angular acceleration of the two active connecting rods are smooth and continuous, the dynamic wear, vibration, noise and stress of a robot driver are greatly reduced, the service life is prolonged, the transplanted plants are uniformly spaced, the field transplanting efficiency is effectively improved, and the labor and the time are saved.
Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered in the protection scope of the present invention.

Claims (6)

1. A method for designing an optimal track of a transplanting robot actuating mechanism is characterized in that the transplanting robot comprises the following steps:
the device comprises a rack (1), two-dimensional translation parallel mechanisms (2), a one-dimensional folding mechanism (3) and a belt type conveying mechanism (4);
the first servo motor (5) is arranged at the top of the rack (1), and the two-dimensional translation parallel mechanisms (2) are positioned on two independent planes through the ball screw mechanism (6);
the two-dimensional translation parallel mechanism (2) comprises a fixing plate (10), a ball screw nut (11), a servo motor spline shaft fixing seat (12), an outer driving connecting rod (13), an inner driving connecting rod (14), an outer driven connecting rod (15), an inner driven connecting rod (16), a moving platform (17) and a triangular connecting frame (18); the ball screw nut (11) and the servo motor spline shaft fixing seat (12) are arranged on the fixing plate (10), and a through hole (18) is formed in the outer side of the ball screw nut (11); one end of an outer driving connecting rod (13) is hinged to a fixing plate (10), the other end of the outer driving connecting rod is hinged to a triangular connecting frame (18), one end of an inner driving connecting rod (14) is hinged to the fixing plate (10), the other end of the inner driving connecting rod is hinged to the triangular connecting frame (18), one end of an inner driven connecting rod (16) is hinged to the triangular connecting frame (18), the other end of the inner driven connecting rod is hinged to the inner side area of a moving platform (17), one end of an outer driven connecting rod (15) is hinged to the triangular connecting frame (18), the other end of the outer driven connecting rod is hinged to the outer side area of the moving platform (17), a second servo motor (19) is arranged on the lower; the guide rail (7) passes through the through hole (18); the first servo motor (5) drives a lead screw to be in threaded connection with a ball screw nut (11);
the one-dimensional folding mechanism (3) comprises a plurality of rectangular frames (20), a plurality of first connecting rods (21), a plurality of second connecting rods (22) and a plurality of grabbing mechanisms (23), wherein the grabbing mechanisms (23) are arranged at the bottoms of the rectangular frames (20); each rectangular frame (20) is provided with a sliding chute (24), the middle parts of a first connecting rod (21) and a second connecting rod (22) are hinged, one end of the first connecting rod (21) is hinged to the bottom of the rectangular frame (20), and one end of the second connecting rod (22) is hinged to the bottom of the adjacent rectangular frame (20); the other end of the first connecting rod (21) is hinged with one end of the adjacent second connecting rod (22) through a hinge shaft (25), protrusions (25) are arranged on two sides of the hinge shaft, and the protrusions (25) slide in an upper sliding groove (24) of the rectangular frame (20); the rectangular frames (20) on the two outermost sides are provided with mounting plates (26), and the mounting plates (26) are fixedly connected with the movable platform (17);
the position vector q of a point P on a motion platform of a kinematic model of the two-dimensional translation parallel mechanism (2) relative to a coordinate system OXZ is as follows:
Figure FDA0002635875730000011
wherein q is [ x z ]]T，
Figure FDA0002635875730000012
When i is 1, sgn (i) is 1, when i is 2, sgn (i) is-1, d is the offset distance between O and Ai, and L is1And L2Is the length of the active and passive links, viAnd wiIs the velocity of the active and passive links, vi＝[cosθ1isinθ1i]T，wi＝[cosθ2isinθ2i]T，θ1iAnd theta2iIs an active connecting rod and a quiltAngle of position of movable link, βiIs the angle between the active and passive links;
angle of actuation theta11And theta12The kinematic equation can be calculated by equation (1) as follows:
Figure FDA0002635875730000021
wherein M isi＝-2L1z，Ni＝-2L1(x-sgn(i)d)；
Figure FDA0002635875730000022
Design parameters and acute angles βiCan be expressed as:
Figure FDA0002635875730000023
the angular velocity vector of the active joint of the parallel robot is related to the linear velocity vector of the end effector by a matrix, and the velocity relationship is as follows:
Figure FDA0002635875730000024
wherein the content of the first and second substances,
Figure FDA0002635875730000025
the speed mapping function is of the form:
Figure FDA0002635875730000026
wherein the content of the first and second substances,
Figure FDA0002635875730000027
the transformation matrix is:
Figure FDA0002635875730000028
the linear velocity of the gripper mechanism in the Y direction is related to the angular velocity of the servo motor driving the bidirectional ball screw as follows:
v＝ny (6)
where v is the linear velocity of the grasping mechanism, n is the angular velocity of the lead screw, and y is the linear distance traversed by the grasping mechanism.
2. The method of claim 1, wherein for a two-dimensional translational parallel device, the constraint relationship is as follows:
Figure FDA0002635875730000031
where is a factor representing the size of the desired workspace relative to the robot dimensions;
in order to have enough space for mounting two servo motors on the frame of the transplanting robot, it is necessary to satisfy:
d≥dmax＝0.100m (8)
in order to avoid singularities in the whole working space and with a favourable force transmission during the operation of the transplanting robot, the kinematic constraint inequality is constrained as:
(L1 2+L2 2-2L1L2cos[β])-H2≤0 (9)
(b/2+e)2+(H+h)2-(L1 2+L2 2-2L1L2cos[β])≤0 (10)
the overall compression performance index η is as follows:
Figure FDA0002635875730000032
wherein
Figure FDA0002635875730000033
Is the index of the global operational performance (p-i-p),
Figure FDA0002635875730000034
is a condition of wηIs that
Figure FDA0002635875730000035
The factor of (2). However, it is preferable that, in the case of,
Figure FDA0002635875730000036
and
Figure FDA0002635875730000037
is a function of k, which is the condition number of the jacobian matrix. The 1/k is more than or equal to 0.5 and less than or equal to 1/k and less than or equal to 1. Therefore, the size of the transplanting robot is obtained by giving constraint conditions to optimize the formula (11);
η(X)→min，X∈R4(12)
wherein X is (L)1L2d H)TRepresenting the design parameters.
3. A method for designing an optimal trajectory for a manipulator of a transfer robot according to claims 1-2, characterized in that a fifth order polynomial is chosen as the constraint for the gripping mechanism:
q(t0)＝q0
Figure FDA0002635875730000038
Figure FDA0002635875730000039
wherein q is0And q isfIs the angular position of the active link or the displacement of the end effector, t0And tfIs the time of the transplanting robot at the beginning and end of the trajectory; the general equation for the law of motion is expressed as:
q(t)＝a0+a1t+a2t2+a3t3+a4t4+a5t5(14)
Figure FDA0002635875730000041
Figure FDA0002635875730000042
wherein a isi1,2, 3, 4, 5 are coefficients of the law of motion equation.
Figure FDA0002635875730000043
And
Figure FDA0002635875730000044
respectively velocity and acceleration. Using equations (14), (15), (16) under the prescribed constraints in equation (13), six simultaneous equations are formulated; solving the equation to obtain the coefficients of the motion law equation as follows:
a0＝q0，a1＝0，a2＝0，
Figure FDA0002635875730000045
the trajectory defining the given constraint of satisfying the maximum acceleration is that the maximum acceleration can be found by solving the quadratic equation:
Figure FDA0002635875730000046
4. a method for designing an optimal trajectory for an actuator of a transplant robot according to claims 1 to 3 wherein there are two of the guide rails (7) disposed at both sides of the ball screw in parallel with the ball screw.
5. The optimum trajectory design method for a transplant robot actuator of claims 1 to 4 wherein the transplanting and the takeout are set in the range of 0.7. ltoreq. 1.2.
6. The optimum trajectory design method for a transplant robot actuator of claims 1 to 5 wherein β is set to 35 ° ≦ β < 180 °.
CN202010830538.0A 2020-08-17 2020-08-17 Optimal track design method for transplanting robot actuating mechanism Pending CN111758352A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010830538.0A CN111758352A (en) 2020-08-17 2020-08-17 Optimal track design method for transplanting robot actuating mechanism

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010830538.0A CN111758352A (en) 2020-08-17 2020-08-17 Optimal track design method for transplanting robot actuating mechanism

Publications (1)

Publication Number Publication Date
CN111758352A true CN111758352A (en) 2020-10-13

Family

ID=72729039

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010830538.0A Pending CN111758352A (en) 2020-08-17 2020-08-17 Optimal track design method for transplanting robot actuating mechanism

Country Status (1)

Country Link
CN (1) CN111758352A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022151223A1 (en) * 2021-01-14 2022-07-21 苏州迈澜医疗科技有限公司 Mechanism having remote center of rotation and working device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102939815A (en) * 2012-10-11 2013-02-27 江苏大学 Seedling taking and seedling planting path planning for pot seedling transplanting robot
CN104641770A (en) * 2015-02-02 2015-05-27 浙江理工大学 Design method for forming transplanting track by using length-variable crankfive-rod driving mechanism with two degrees of freedom
CN104641771A (en) * 2015-02-02 2015-05-27 浙江理工大学 Design method for forming transplanting track by using five-rod driving mechanism with two degrees of freedom
JP2020080685A (en) * 2018-11-20 2020-06-04 井関農機株式会社 Seedling transplanter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102939815A (en) * 2012-10-11 2013-02-27 江苏大学 Seedling taking and seedling planting path planning for pot seedling transplanting robot
CN104641770A (en) * 2015-02-02 2015-05-27 浙江理工大学 Design method for forming transplanting track by using length-variable crankfive-rod driving mechanism with two degrees of freedom
CN104641771A (en) * 2015-02-02 2015-05-27 浙江理工大学 Design method for forming transplanting track by using five-rod driving mechanism with two degrees of freedom
JP2020080685A (en) * 2018-11-20 2020-06-04 井関農機株式会社 Seedling transplanter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022151223A1 (en) * 2021-01-14 2022-07-21 苏州迈澜医疗科技有限公司 Mechanism having remote center of rotation and working device

Similar Documents

Publication Publication Date Title
Rahul et al. Design and development of a 5R 2DOF parallel robot arm for handling paper pot seedlings in a vegetable transplanter
CN110832991B (en) Picking machine based on image recognition
KR20210129240A (en) Mathod and Apparatus for Hanlding Material with Multiple End-Effectors
CN104526685B (en) Containing the redundant drive plane two-degree-of-freedoparallel parallel manipulator of parallelogram side chain
JP6630727B2 (en) Horizontal articulated robot
Ndawula et al. Conceptual design and kinematic analysis of a novel open field 3dof multi-gripper pot seedlings transplanting robot
CN109845491B (en) Picking and grading method for picking circular grading and collecting robot by utilizing double-arm apples
CN110192472B (en) Round grading collection robot for picking apples with two arms
US20150336266A1 (en) Pure translational serial manipulator robot having three degrees of freedom with a reduced space requirement
CN111758352A (en) Optimal track design method for transplanting robot actuating mechanism
CN104708619A (en) Three-degree-of-freedom transfer robot with movable support
CN113119139A (en) Fruit and vegetable picking machine based on six-degree-of-freedom mechanical arm
CN213523049U (en) Transplanting robot
CN104690723A (en) Two-degree-of-freedom positioning mechanism and telescopic driving type multiple-degree-of-freedom mixed-connected robot thereof
CN103895008A (en) Space three-dimensional translation parallel robot mechanism only containing revolute pairs
CN109079761B (en) Two-rotation one-movement parallel robot with closed-loop branched chain
CN103481278A (en) Three-translational spatial parallel robot mechanism
CN105500350A (en) Three-translation high-speed sorting parallel manipulator
CN106514624B (en) A kind of restructural four-degree-of-freedparallel parallel manipulator
Assal et al. Optimum Design and FEA of a Hybrid Parallel-deployable Structure-based 3-DOF Multi-gripper Translational Robot for Field Pot Seedlings Transplanting.
CN116602102A (en) Robot transplanting mechanism
CN113442156B (en) Flexible clamp holder based on two-finger robot hand
CN104227710A (en) Spatial three-degree-of-freedom parallel mechanism
CN110142746B (en) Three-translation parallel robot mechanism with zero coupling degree and analytic position positive solution
CN214055306U (en) Portal frame manipulator and plant factory automation line

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination