XACRO案例:SCARA

需求介绍

采用xacro方式模拟建造一个类似于ABB的SCARA类似的产品。

实现需求

模型分析

两个可以旋转的轴，一个可以上下滑动的轴。

总共是3个joint，4个link.

建立模型

<?xml version="1.0"?>
<robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="scara">

    <xacro:property name="base_width" value="0.3"/>
    <xacro:property name="base_height" value="0.4"/>
    <xacro:property name="base_len" value="0.6"/>

    <xacro:property name="link1_width" value="0.2"/>
    <xacro:property name="link1_height" value="0.8"/>
    <xacro:property name="link1_len" value="0.1"/>

    <xacro:property name="link2_width" value="0.2"/>
    <xacro:property name="link2_height" value="0.6"/>
    <xacro:property name="link2_len" value="0.3"/>

    <xacro:property name="link3_len" value="1"/>
    <xacro:property name="link3_radius" value="0.01"/>

    <xacro:macro name="HMColor" params="name">
        <material name="${name}">
            <xacro:if value="${name=='red'}">
                <color rgba="1.0 0 0 1.0"/>
            </xacro:if>
            <xacro:if value="${name=='green'}">
                <color rgba="0 1.0 0 1.0"/>
            </xacro:if>
            <xacro:if value="${name=='blue'}">
                <color rgba="0 0 1.0 1.0"/>
            </xacro:if>
            <xacro:if value="${name=='white'}">
                <color rgba="1.0 1.0 1.0 1.0"/>
            </xacro:if>
        </material>
    </xacro:macro>

    <!-- base link -->
    <link name="base_link">
        <visual>
            <origin xyz="0 0 ${base_len / 2}" rpy="0 0 0"/>
            <geometry>
                <box size="${base_width} ${base_height} ${base_len}"/>
            </geometry>
            <xacro:HMColor name="white"/>
        </visual>
    </link>

    <!-- link1 -->
    <link name="link1">
        <visual>
            <origin xyz="0 -${link1_height/2 + base_width/2 - base_height/2} ${link1_len/2}" rpy="0 0 0"/>
            <geometry>
                <box size="${link1_width} ${link1_height} ${link1_len}"/>
            </geometry>
            <xacro:HMColor name="blue"/>
        </visual>
    </link>

    <!-- joint: toggle link -->
    <joint name="joint0" type="revolute">
        <origin xyz="0 -${base_height/2 - base_width/2} ${base_len}" rpy="0 0 0"/>
        <axis xyz="0 0 1"/>
        <parent link="base_link"/>
        <child link="link1"/>

        <limit effort="30" velocity="1.0" lower="-2.5" upper="2.5"/>
    </joint>


    <!-- link2 -->
    <link name="link2">
        <visual>
            <origin xyz="0 -0.2 ${link2_len/2}" rpy="0 0 0"/>
            <geometry>
                <box size="${link2_width} ${link2_height} ${link2_len}"/>
            </geometry>
            <xacro:HMColor name="green"/>
        </visual>
    </link>

    <!-- joint: toggle link -->
    <joint name="joint1" type="revolute">
        <origin xyz="0 -${link1_height - link1_width} ${link1_len}" rpy="0 0 0"/>
        <axis xyz="0 0 1"/>
        <parent link="link1"/>
        <child link="link2"/>

        <limit effort="30" velocity="1.0" lower="-2.5" upper="2.5"/>
    </joint>

    <!-- link3 -->
    <link name="link3">
        <visual>
            <origin xyz="0 0 0" rpy="0 0 0"/>
            <geometry>
                <cylinder length="${link3_len}" radius="${link3_radius}"/>
            </geometry>
            <xacro:HMColor name="red"/>
        </visual>
    </link>

    <!-- joint: toggle link -->
    <joint name="joint2" type="prismatic">
        <origin xyz="0 -${link2_height - link2_width} ${link2_len/2}" rpy="0 0 0"/>
        <axis xyz="0 0 1"/>
        <parent link="link2"/>
        <child link="link3"/>

        <limit effort="30" velocity="1.0" lower="-0.35" upper="0.35"/>
    </joint>

</robot>