CN102939815A - Seedling taking and seedling planting path planning for pot seedling transplanting robot - Google Patents

Abstract

The present invention plans and designs the path and motion law of the seedling picking and planting process of the pot seedling transplanting robot, so as to realize the transplanting operation requirements of accurate positioning, grasping, and high-speed moving planting. The working mode of the seedling claw is set to five steps of "positioning grabbing, straight up, straight translation, straight down, positioning transplant"; Linear motion is adopted; the motion law of each segment of the linear motion trajectory is set as four steps of "stop, accelerate, decelerate, and stop", and the trajectory control function adopts a polynomial of degree 5. On the premise of ensuring the stable operation of the seedling claws, the transplanting efficiency is improved.

Description

Path planning for seedling picking and planting by a pot seedling transplanting robot

technical field

The invention belongs to the field of facility agricultural equipment, and in particular relates to a method for path planning and motion law design during the movement process of seedling picking claws of a seedling-picking robot for transplanting seedlings in pots and pots.

Background technique

Compared with conventional seedling raising methods, plug seedling raising has the advantages of labor saving, labor saving, resource saving, easy management and protection of agricultural ecological environment. It has become the most important seedling raising method at home and abroad, and is widely used in tobacco, trees, vegetables, flowers crop production. In the seedling raising process, in order to obtain enough growth space for the crops, it is necessary to transplant the seedlings from the high-density tray to the low-density tray or flowerpot. Due to the shortcomings of manual transplanting, such as high labor intensity, low operating efficiency, high production cost, and difficulty in guaranteeing transplanting quality, since the 1980s, domestic and foreign efforts have been devoted to the development of transplanting robots for seedlings in pots and pots.

In 1995, Japan developed the PT6000 transplanting robot, which picked up the plug-in seedlings through the plug-in seedling puller, and then moved to the position of the empty pot-shaped container under the drive of the manipulator, and then put down the seedlings in the pot. The transplantation was completed; in 2001, South Korea K.H.Ryu et al. developed a seedling transplanting robot with the help of the Cartesian coordinate system. Combined to realize the grasping, holding and releasing of pot seedlings; in 2002, South Korea W.C. Choi developed a seedling picking device consisting of a trajectory generator, grasping pointer and pointer driver.

The patent "A Plug Seedling Transplanting Machine" (Application No. 200910187621.4) discloses a transplanting machine that can actively transplant vegetables and flower plug seedlings of different specifications from high-density plugs to low-density plugs or containers; The patent "Pneumatic claw-type seedling picking manipulator" (application number 201120239257.4) discloses a pneumatic clamping and seedling picking device that can pick up multiple pot seedlings at one time; the patent "a greenhouse seedling transplanting machine" (application number is 201120382235.3) discloses a greenhouse rice seedling transplanting machine with an adjustable number of manipulators and a seedling unloading blowing nozzle.

In facility agricultural production, the transplanting path planning of the pot seedling transplanting robot is of great significance. During the transplanting of pot seedlings, it is not only required that the seedling claws can accurately reach the target point, but also must move quickly along the required trajectory within a certain range of accuracy. At the same time, in order to ensure the stability of the movement and prevent the soil from being damaged by earthquake , must also meet certain speed and acceleration requirements. However, although a lot of research has been done on the transplanting of pot seedlings at home and abroad, and various pot seedling transplanting robots that can realize transplanting operations have been developed successively, they have not considered the stability and rapidity of the movement. There are no relevant research reports on the path planning and motion law design of the seedling claws of the transplanting robot.

In order to realize the operation requirements of the pot seedling transplanting robot for accurate positioning, grasping and fast moving planting, the present invention provides a seedling picking and planting path planning method for the pot seedling transplanting robot. Transplanting efficiency.

Contents of the invention

The purpose of the present invention is to plan a movement path for the seedling-taking claw of the seedling transplanting robot that can realize seedling picking, seedling delivery, seedling planting, and return to the whole transplanting process, and design its motion law to ensure that the pot seedlings The pot seedling transplanting robot improves the transplanting efficiency and operation stability under the premise of accurate positioning, grasping and fast moving planting operations.

To achieve the above object, the technical scheme adopted in the present invention is as follows:

The path planned by the pot seedling transplanting robot to complete the seedling picking and planting actions is a three-segment motion mode of straight up, straight translation and straight down, that is, the seedling claws drop straight above the pot seedlings to be picked to pick the seedlings, after picking the seedlings Rapidly rises in a straight line, rises to the height of the seedlings, then translates to send the seedlings, transplants the seedlings to the planting position, then quickly descends in a straight line to plant the seedlings, and returns to the original road after the seedlings are planted.

The velocity and acceleration at the start and end of each linear motion trajectory are zero.

The movement law of each operation stage is set to four steps of "stop, accelerate, decelerate, stop".

The first-order and second-order derivatives of the displacement motion law of each linear motion trajectory with respect to time are continuous.

The control function of each section of linear motion trajectory is a polynomial of degree 5.

With known boundary conditions $\left\{\begin{array}{c}{t}_{}\end{array}\right.$$\left\{\begin{array}{c}{}_0=0,a=0,v=0,\mathrm{the\; s}=0\\ {\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HDA00002243398700011.png,HDA00002243398700012.png"\; state="\{\{state\}\}">t</figure-callout>}}_1=T,a=0,v=0,\mathrm{the\; s}=S\end{array}\right.,$ The law of motion is:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 10</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 15</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 6</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 30</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; [</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 60</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 60</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 6</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 6</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; =</span>\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 5.7735</span>}\mathrm{<span\; class="notranslate">\; S</span>}}{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}}\end{array}\right.$

Among them, t is time, s is displacement, v is velocity, a is acceleration, j is jerk, T is the time required for taking seedling claws through each section of straight line trajectory, S is the time required for taking seedling claw through each section of straight line trajectory length, a _max is the maximum acceleration allowed during the movement of the seedling claw.

The present invention has the following advantages:

(1) The working mode of the pot seedling transplanting robot is set to fast "positioning grabbing, straight up, straight line translation, straight line down and positioning transplanting", which meets the operation requirements of precise positioning grabbing and transplanting. In addition, the linear motion trajectory It can also avoid interference between the seedling claws and the pot seedlings;

(2) The motion law of each segment of the linear motion trajectory is set to four steps of "stop, acceleration, deceleration, and stop", and the 5th degree polynomial motion law is used as the operation control function of each trajectory. The displacement motion law is about time The first and second derivatives are continuous, and the third derivative is limited, which improves the transplanting efficiency under the premise of ensuring the stable operation of the seedling claws.

Description of drawings

Figure 1 The trajectory of the seedling claws during the transplanting process.

Fig. 2 The velocity diagram of each straight line segment.

Fig. 3 is a diagram of the motion acceleration of each straight line segment.

Fig. 4. Velocity graphs of three kinds of motion laws.

Fig. 5 Acceleration curves of three kinds of motion laws.

In the figure: 1. Seedling feeding tray 2. Seedling planting tray 3. Movement track of seedling claws 4.5 degree polynomial movement law 5. Cycloidal movement law 6.7 degree polynomial movement law.

Detailed ways

Below in conjunction with accompanying drawing, the present invention will be further described:

As shown in Figure 1, in the pot seedling transplanting operation, the movement trajectory of the transplanting robot’s seedling claws consists of three straight lines, and a single operating cycle is:

(1) Vertically descend to point A in the center of the positioning hole of the seedling tray 1 to be transplanted, and take the seedlings;

(2) Rise vertically to point B;

(3) Move horizontally to point C above the positioning hole of the seedling tray 2;

(4) Vertically descend to point D in the center of the positioning hole of the seedling planting tray 2 to plant seedlings;

(5) Rise vertically to point C;

(6) Move horizontally back to above the positioning hole of the next seedling to be transplanted in the seedling tray 1 .

It can be seen that the transplanting of seedling claws to each pot seedling needs to go through two moving processes of forward and backward, and in each process, the seedling claws must sequentially go through three operating stages of "rising, translation, and descending".

As shown in Figure 2 and Figure 3, the speed and acceleration change line diagrams using the 5th degree polynomial motion law, it can be seen from the figure that each operation stage follows the motion law of "stop, accelerate, decelerate, stop", that is, A, B, The velocity and acceleration at points C and D are both 0, and the first-order and second-order derivatives of the displacement motion law of each linear motion trajectory with respect to time are continuous. smoothness.

According to the law of motion theory, there are many laws of motion that meet the above conditions, but the commonly used ones are cycloidal law of motion, polynomial of degree 5 and polynomial of degree 7. Under the conditions of known displacement S and maximum allowable acceleration a _max , Its motion law function model is as follows:

(1) The law of cycloidal motion

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="max\; T"\; filenames="HDA00002243398700011.png,HDA00002243398700021.png"\; state="\{\{state\}\}">max</figure-callout></span><figure-callout\; id="2"\; label="max\; T"\; filenames="HDA00002243398700011.png,HDA00002243398700021.png"\; state="\{\{state\}\}">\; </figure-callout>}}\frac{\mathrm{<span\; class="notranslate">\; </span>}}{}\frac{\mathrm{<span\; class="notranslate">T</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="T"\; filenames="HDA00002243398700011.png,HDA00002243398700021.png"\; state="\{\{state\}\}">T</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="max\; T"\; filenames="HDA00002243398700011.png,HDA00002243398700021.png"\; state="\{\{state\}\}">max</figure-callout></span><figure-callout\; id="2"\; label="max\; T"\; filenames="HDA00002243398700011.png,HDA00002243398700021.png"\; state="\{\{state\}\}">\; </figure-callout>}}\frac{\mathrm{<span\; class="notranslate">\; </span>}}{}\frac{\mathrm{<span\; class="notranslate">T</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; =</span>\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;S</span>}}{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}}\end{array}\right.$

(2) 5th degree polynomial motion rule

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 10</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 15</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 6</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 30</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; [</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 60</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 5.7735</span>}}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; =</span>\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 5.7735</span>}\mathrm{<span\; class="notranslate">\; S</span>}}{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}}\end{array}\right.$

(3) 7th degree polynomial motion law

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 7.51</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 35</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 84</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 70</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 20</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 7</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 140</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 7.51</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; [</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; -</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 420</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 7.51</span>}}<span\; class="notranslate">\; [</span>{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 4</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 5</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; ]</span>\\ \mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; =</span>\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 7.51</span>}\mathrm{<span\; class="notranslate">\; S</span>}}{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}}\end{array}\right.$

In the above-mentioned law of motion function model: t is time, s is displacement, v is velocity, a is acceleration, T is the time required for getting seedling claws to go through each section of straight line track segment, S is to get seedling claw to go through each section of straight line track section. length, a _max is the maximum acceleration allowed during the movement of the seedling claw.

The maximum allowable acceleration a _max =60m/s ² for the pot seedling transplanting robot, the straight-line rising and falling height is 120mm, and the horizontal moving distance is 600mm. Calculate the time required for the seedling claw to complete one cycle of rising, translation and falling motion T as follows:

(1) Law of sinusoidal motion

计算各直线段运动时间，得完成1个运动周期所需时间：according to

To calculate the motion time of each straight line segment, the time required to complete a motion cycle is obtained:

T=0.122+0.250+0.122=0.494 (S)

(2) 5th degree polynomial motion rule

计算各直线段运动时间，得完成1个运动周期所需时间：according to

To calculate the motion time of each straight line segment, the time required to complete a motion cycle is obtained:

T=0.107+0.240+0.107=0.454 (S)

(3) 7th degree polynomial motion rule

计算各直线段运动时间，得完成1个运动周期所需时间：according to

To calculate the motion time of each straight line segment, the time required to complete a motion cycle is obtained:

T=0.122+0.274+0.122=0.518 (S)

From the above calculation results, it can be seen that the time required to complete the motion cycle of "rising, translation, and descending" by using the 5th degree polynomial motion law is the shortest.

Using the mathematical software Matlab, the velocity and acceleration diagrams of cycloid motion law, polynomial motion law of degree 5 and polynomial degree 7 in the 600mm horizontal straight line segment are obtained, as shown in Figures 4 and 5. After comparison and analysis, it is found that:

(1) The maximum speed of the 5th degree polynomial motion law is smaller than the cycloid and 7th degree polynomial motion law;

(2) When the fifth-degree polynomial motion law reaches the maximum speed and acceleration, the time taken is the shortest;

When the pot seedling transplanting robot of the present invention adopts the 5th degree polynomial motion law, the running stability of the pot seedlings taken by its seedling claws is better than cycloid and 7th degree polynomial motion law, and the time used for transplanting pot seedlings is less than cycloid and 7th polynomial motion law. The 7th-degree polynomial motion law, so the 5th-degree polynomial motion law is selected as the trajectory planning function for seedling picking and planting, which can meet its stability requirements and improve transplanting efficiency.

Claims (5)

1. A pot seedling transplanting robot takes seedlings and plants seedling path planning, it is characterized in that: the path planning that the pot seedling transplanting robot completes to get seedlings, the action of planting seedlings is a three-segment motion pattern of straight up, straight translation and straight down , that is, the seedling claws drop straight above the pot seedlings to be taken to take the seedlings, and then rise quickly and straightly after taking the seedlings, and then move the seedlings in translation after rising to the height of the seedlings. way back. 2. The seedling-taking and planting path according to claim 1, characterized in that: the speed and acceleration of the seedling claws at the starting point and the end point of each segment of the linear motion track are zero. 3. The path for taking seedlings and planting seedlings according to claim 1, characterized in that: for each section of linear motion trajectory, the law of motion of the seedling claws of the transplanting robot is set to four steps of "stop, accelerate, decelerate, stop" . 4. The motion law according to claim 3, characterized in that: the first-order and second-order derivatives of the displacement motion law of each linear motion track with respect to time are continuous. 5. According to claim 2, 3, 4 described linear motion track and motion law, it is characterized in that: the control function of each section of linear motion track is a polynomial of degree 5.

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