摘要: 原創博客:轉載請標明出處:http://www.cnblogs.com/zxouxuewei/
各位博友好長時間又沒有寫博客了,突然發現上班和在學校是不一樣的,在公司的卻沒有時間寫博客了,不過還有好多小伙伴會遇到不一樣的問題,今天我在總結的同時,將遇到的問題也匯集一下:
一。首先統一硬件:
1>不過對於ros軟件平台下的機器人底盤來說,沒有什么是統一的,標准的,只有完成ros層的參數透傳和執行就可以了。不過今天我所用的硬件不是我之前博客中提到的兩輪差分的。 而是3輪全向的,具體是3個時代超群的直流無刷電機,3個全向輪,3個直流無刷電機驅動器(不過驅動器的速度反饋太慢了,所以我是直接將霍爾的接口在接到STM32 主控板上的,采用定時 器正交解碼后計算的速度,由於電機轉動一圈的霍爾跳變沿只有8個,所以,我們不能用時間片脈沖數的方式去計算速度,要通過,兩次跳變的時間和移動的距離計算速度。在我的測試下,最終效 果還是不錯的)
2>剩下的就是每一個小伙伴都要經歷的就是,底盤的運動學正逆解,具體的推算過程有好多論文可以看,所以也就不多說的,兩輪差分的比較簡單,3輪全向的可以看我的上一篇博 文,http://www.cnblogs.com/zxouxuewei/p/5871470.html(強烈建 議,有些人寫的論文公式都是錯的,具體一定要自己推算一下,不然后面楚翔素的變換不正常的的情況就會讓你特別痛苦)。
二。我的STM32部分代碼分享給大家,希望大家不要見笑,不過底層的東西沒有算法那么復雜,所以大家都可以做的,在此就貼出重要的部分代碼:
1》我的3個輪子的對象描述。
typedef struct _kinematics_
{
float Target_Speed; //運動學正解后的速度 m/s
int Moto_Speed_Output; //給定的轉速 rpm/s 實際的電機要乘以減速比 36
float Input_Speed; //電機控制器輸入捕獲的實際速度 m/s
unsigned char TIMCH1_CAPTURE_STA; //輸入捕獲狀態
unsigned short TIMCH1_CAPTURE_VAL; //輸入捕獲值
float xyz_Target_value; //通過上位機或者手機遙控器給定的xyz方向上的速度
unsigned char D_Flag;
}_struct_Pos_;
_struct_Pos_ Kinematics_Positive1 = {0,0,0,0,0,0};
_struct_Pos_ Kinematics_Positive2 = {0,0,0,0,0,0};
_struct_Pos_ Kinematics_Positive3 = {0,0,0,0,0,0};
#define VX_VALUE 0.5f //(0.5f)
#define VY_VALUE 0.72f //(sqrt(3)/2.0)
#define L_value 0.219f // 0.2/角速度校准參數(0.915)
#define RADIUS_value 0.386
#define REDUCTION_RATIO 36 //減速比
/**********************************************
* describetion: 底盤運動學正解函數
* param: vx: x方向的速度
* vy: y方向的速度
* vz: z軸的速度
* return: none
* author: 周學偉
* date : 2016-9-16
*************************************************/
void Speed_Moto_Control(float vx,float vy,float vz)
{
Kinematics_Positive1.Target_Speed = (-VX_VALUE*vy + VY_VALUE*vx + L_value*vz);//正解函數,具體推算過程請查看我的博客
Kinematics_Positive2.Target_Speed = (-VX_VALUE*vy - VY_VALUE*vx + L_value*vz);
Kinematics_Positive3.Target_Speed = (vy + L_value*vz);
Kinematics_Positive1.Moto_Speed_Output = -(Kinematics_Positive1.Target_Speed * REDUCTION_RATIO / RADIUS_value); //單位m/s
Kinematics_Positive2.Moto_Speed_Output = -(Kinematics_Positive2.Target_Speed * REDUCTION_RATIO / RADIUS_value);
Kinematics_Positive3.Moto_Speed_Output = -(Kinematics_Positive3.Target_Speed * REDUCTION_RATIO / RADIUS_value);
Control_Moto_Speed(MOTO1,Kinematics_Positive1.Moto_Speed_Output);
Control_Moto_Speed(MOTO2,Kinematics_Positive2.Moto_Speed_Output);
Control_Moto_Speed(MOTO3,Kinematics_Positive3.Moto_Speed_Output);
}
逆解過程
movement_cul.upload_speed.Y_speed = -(2.0*Kinematics_Positive3.Input_Speed-Kinematics_Positive1.Input_Speed-Kinematics_Positive2.Input_Speed)/3.0;
movement_cul.upload_speed.X_speed = -(Kinematics_Positive1.Input_Speed - Kinematics_Positive2.Input_Speed)/1.442;
movement_cul.upload_speed.Z_speed = -(Kinematics_Positive1.Input_Speed + Kinematics_Positive2.Input_Speed + Kinematics_Positive3.Input_Speed)/(L_value*3);
2》做完速度的輸入正解和逆解輸出后,下面進入機器人的線速度和角速度校准,參考我的博客:http://www.cnblogs.com/zxouxuewei/p/5482302.html#3525543
3》下面我們准備導航所需要的包。
a.ros-indigo-gampping :我們不需要修改包內的東西,所以直接安裝可執行文件就好了。
sudo apt-get install ros-indigo-slam-gmapping
b.安裝雷達的驅動(我的是robopack),直接將提供的ros驅動包拷貝到工作空間中,
c.安裝導航定位包,navigation 進入git:https://github.com/ros-planning/navigation/tree/indigo-devel,下載和自己ros版本匹配的包,解壓到自己的工作空間中,
cd ~/catkin_ws
catkin_make
indigo的navigation包會出現一個依賴問題,:Orocos-bfl not found while installing navigation stack ROS indigo + Ubuntu 14.04
解決方法: rosdep install --from-paths src --ignore-src --rosdistro indigo -y
d.由於導航包在/cmd_val下發布的移動數據加速度會過於不友好,所以我們需要對速度做平滑處理,其實就是控制加速,一般通過濾波即可實現,在此我們采用turtlebot的平滑包即可,
安裝平滑包yocs_velocity_smoother,具體的平滑算法和輸入切換請自己閱讀源碼。
apt-get install ros-indigo-yocs-velocity-smoother
三。1.所有的包准包好后,我們去准備啟動所需的launch文件,首先是機器人地盤的啟動文件ZHXWBOT_start.launch:
<launch> <param name="use_sim_time" value="false" /> <node name="link_laser" pkg="tf" type="static_transform_publisher" args="0.15 0 0.15 0 0 0 base_link laser 50"/> <node name="link_footprint" pkg="tf" type="static_transform_publisher" args="0 0 0 0 0 0 base_link base_footprint 50"/> <node pkg="odom_tf_package" type="tf_broadcaster_node" name="serial_send_recevice" output="screen"/> <include file="$(find odom_tf_package)/launch/include/rplidar_ros.launch.xml">
</include> <arg name="node_name" value="velocity_smoother"/> <arg name="nodelet_manager_name" value="nodelet_manager"/> <arg name="config_file" value="$(find odom_tf_package)/config/yocs_velocity_smoother.yaml"/> <arg name="raw_cmd_vel_topic" value="cmd_vel"/> <arg name="smooth_cmd_vel_topic" value="smoother_cmd_vel"/> <arg name="robot_cmd_vel_topic" value="robot_cmd_vel"/> <arg name="odom_topic" value="odom"/> <!-- nodelet manager --> <node pkg="nodelet" type="nodelet" name="$(arg nodelet_manager_name)" args="manager"/> <!-- velocity smoother --> <include file="$(find yocs_velocity_smoother)/launch/velocity_smoother.launch"> <arg name="node_name" value="$(arg node_name)"/> <arg name="nodelet_manager_name" value="$(arg nodelet_manager_name)"/> <arg name="config_file" value="$(arg config_file)"/> <arg name="raw_cmd_vel_topic" value="$(arg raw_cmd_vel_topic)"/> <arg name="smooth_cmd_vel_topic" value="$(arg smooth_cmd_vel_topic)"/> <arg name="robot_cmd_vel_topic" value="$(arg robot_cmd_vel_topic)"/> <arg name="odom_topic" value="$(arg odom_topic)"/> </include> </launch>
2.然后去准備建圖包的啟動文件gmapping.launch
<launch> <arg name="scan_topic" default="scan" /> <node pkg="gmapping" type="slam_gmapping" name="slam_gmapping" output="screen" clear_params="true"> <!--because my used rtabmap_ros --> <param name="odom_frame" value="/odom""/> <!--param name="odom_frame" value="/base_controller/odom""/--> <param name="map_update_interval" value="30.0"/> <!-- Set maxUrange < actual maximum range of the Laser --> <param name="maxRange" value="5.0"/> <param name="maxUrange" value="4.5"/> <param name="sigma" value="0.05"/> <param name="kernelSize" value="1"/> <param name="lstep" value="0.05"/> <param name="astep" value="0.05"/> <param name="iterations" value="5"/> <param name="lsigma" value="0.075"/> <param name="ogain" value="3.0"/> <param name="lskip" value="0"/> <param name="srr" value="0.01"/> <param name="srt" value="0.02"/> <param name="str" value="0.01"/> <param name="stt" value="0.02"/> <param name="linearUpdate" value="0.5"/> <param name="angularUpdate" value="0.436"/> <param name="temporalUpdate" value="-1.0"/> <param name="resampleThreshold" value="0.5"/> <param name="particles" value="80"/> <!-- <param name="xmin" value="-50.0"/> <param name="ymin" value="-50.0"/> <param name="xmax" value="50.0"/> <param name="ymax" value="50.0"/> make the starting size small for the benefit of the Android client's memory... --> <param name="xmin" value="-1.0"/> <param name="ymin" value="-1.0"/> <param name="xmax" value="1.0"/> <param name="ymax" value="1.0"/> <param name="delta" value="0.05"/> <param name="llsamplerange" value="0.01"/> <param name="llsamplestep" value="0.01"/> <param name="lasamplerange" value="0.005"/> <param name="lasamplestep" value="0.005"/> <remap from="scan" to="$(arg scan_topic)"/> </node> </launch>
3,導航包(move_base)和定位(amcl)的啟動文件:zxbot_amcl.launch
<launch> <param name="use_sim_time" value="false" /> <!-- Set the name of the map yaml file: can be overridden on the command line. --> <arg name="map" default="map.yaml" /> <!--node name="map_odom" pkg="tf" type="static_transform_publisher" args="0 0 0 0 0 0 map odom 50"/--> <!-- Run the map server with the desired map --> <node name="map_server" pkg="map_server" type="map_server" args="$(find odom_tf_package)/maps/$(arg map)"/> <!-- The move_base node --> <include file="$(find odom_tf_package)/launch/move_base_amcl.launch" /> <!--zxw add Fire up AMCL--> <include file="$(find odom_tf_package)/launch/tb_amcl.launch" /> </launch>
move_base_amcl.launch:
<launch> <node pkg="move_base" type="move_base" respawn="false" name="move_base" output="screen" clear_params="true"> <rosparam file="$(find odom_tf_package)/config/zxbotconfig/costmap_common_params.yaml" command="load" ns="global_costmap" /> <rosparam file="$(find odom_tf_package)/config/zxbotconfig/costmap_common_params.yaml" command="load" ns="local_costmap" /> <rosparam file="$(find odom_tf_package)/config/zxbotconfig/local_costmap_params.yaml" command="load" /> <rosparam file="$(find odom_tf_package)/config/zxbotconfig/global_costmap_params.yaml" command="load" /> <rosparam file="$(find odom_tf_package)/config/zxbotconfig/base_local_planner_params.yaml" command="load" /> <rosparam file="$(find odom_tf_package)/config/nav_obstacles_params.yaml" command="load" /> </node> </launch>
tb_amcl.launch:
<launch> <arg name="use_map_topic" default="false"/> <arg name="scan_topic" default="scan"/> <node pkg="amcl" type="amcl" name="amcl" clear_params="true"> <param name="use_map_topic" value="$(arg use_map_topic)"/> <!-- Publish scans from best pose at a max of 10 Hz --> <param name="odom_model_type" value="diff"/> <param name="odom_alpha5" value="0.1"/> <param name="gui_publish_rate" value="10.0"/> <param name="laser_max_beams" value="60"/> <param name="laser_max_range" value="12.0"/> <param name="min_particles" value="500"/> <param name="max_particles" value="2000"/> <param name="kld_err" value="0.05"/> <param name="kld_z" value="0.99"/> <param name="odom_alpha1" value="0.2"/> <param name="odom_alpha2" value="0.2"/> <!-- translation std dev, m --> <param name="odom_alpha3" value="0.2"/> <param name="odom_alpha4" value="0.2"/> <param name="laser_z_hit" value="0.5"/> <param name="laser_z_short" value="0.05"/> <param name="laser_z_max" value="0.05"/> <param name="laser_z_rand" value="0.5"/> <param name="laser_sigma_hit" value="0.2"/> <param name="laser_lambda_short" value="0.1"/> <param name="laser_model_type" value="likelihood_field"/> <!-- <param name="laser_model_type" value="beam"/> --> <param name="laser_likelihood_max_dist" value="2.0"/> <param name="update_min_d" value="0.25"/> <param name="update_min_a" value="0.2"/> <param name="odom_frame_id" value="odom"/> <param name="resample_interval" value="1"/> <!-- Increase tolerance because the computer can get quite busy --> <param name="transform_tolerance" value="1.0"/> <param name="recovery_alpha_slow" value="0.0"/> <param name="recovery_alpha_fast" value="0.0"/> <remap from="scan" to="$(arg scan_topic)"/> </node> </launch>
4.導航的配置參數如下:
base_local_planner_params.yaml
controller_frequency: 2.0 recovery_behavior_enabled: false clearing_rotation_allowed: false TrajectoryPlannerROS: max_vel_x: 0.3 min_vel_x: 0.05 max_vel_y: 0.0 # zero for a differential drive robot min_vel_y: 0.0 min_in_place_vel_theta: 0.5 escape_vel: -0.1 acc_lim_x: 2.5 acc_lim_y: 0.0 # zero for a differential drive robot acc_lim_theta: 3.2 holonomic_robot: false yaw_goal_tolerance: 0.1 # about 6 degrees xy_goal_tolerance: 0.15 # 10 cm latch_xy_goal_tolerance: false pdist_scale: 0.8 gdist_scale: 0.6 meter_scoring: true heading_lookahead: 0.325 heading_scoring: false heading_scoring_timestep: 0.8 occdist_scale: 0.1 oscillation_reset_dist: 0.05 publish_cost_grid_pc: false prune_plan: true sim_time: 2.5 sim_granularity: 0.025 angular_sim_granularity: 0.025 vx_samples: 8 vy_samples: 0 # zero for a differential drive robot vtheta_samples: 20 dwa: true simple_attractor: false
costmap_common_params.yaml
obstacle_range: 2.5 raytrace_range: 3.0 robot_radius: 0.30 inflation_radius: 0.15 max_obstacle_height: 0.6 min_obstacle_height: 0.0 observation_sources: scan scan: {data_type: LaserScan, topic: /scan, marking: true, clearing: true, expected_update_rate: 0}
global_costmap_params.yaml
global_costmap: global_frame: /map robot_base_frame: /base_link update_frequency: 1.0 publish_frequency: 0 static_map: true rolling_window: false resolution: 0.01 transform_tolerance: 0.5 map_type: costmap
local_costmap_params.yaml
local_costmap: global_frame: /odom robot_base_frame: /base_link update_frequency: 1.0 publish_frequency: 1.0 static_map: false rolling_window: true width: 6.0 height: 6.0 resolution: 0.01 transform_tolerance: 0.5 map_type: costmap
四,准備好以上所有的啟動文件和配置參數后,我們開始創建地圖和導航,
1.創建地圖:
roslaunch odom_tf_package ZHXWBOT_start.launch //啟動地盤控制器 roslaunch odom_tf_package gmapping.launch roscd odom_tf_package/maps/ rosrun map_server map_saver -f mymap
然后會產生以下地圖文件
mymap.pgm mymap.yaml
2.開始導航
roslaunch odom_tf_package ZHXWBOT_start.launch //啟動地盤控制器
roslaunch odom_tf_package zxbot_amcl.launch map:=mymap.yaml
rosrun rviz rviz -d `rospack find odom_tf_package`/nav_test.rviz
然后指定導航目標,開始自己慢慢玩吧,不過因為我的TF變換主要是里程計更新的,車體打滑或者地盤電機震盪都會積累誤差,所以我們必須添加視覺里成計或者閉環檢測。