Sufyan's profile - activity

can the camera callibration be the problem ? because besides all the working i get a small error on this node which is

ar_track_alvar not precise and not producing repeatable results In my project i am taking a picture from an IP camera an

ar_track_alvar not precise and not producing repeatable results In my project i am taking a picture from an IP camera an

Hey!! sorry for late reply. I am using a 1 MP camera and my ar tag is about 4 meters from camera .. I have edited the qu

currently I am working on a project which is as following. 1-a camera is mounted on cieling of my room 2- image processing is used to localize the robot(using ar alvar track package) and obstacles. 3- path planning is done using A* algorithm i am done with all that is mentioned above. Now i want my robot to follow the planned path. but according to the description of Navigation stack package, you must need a Laser sensor for sensor stream input... Is there anyway to use this package for my project or is there any other solution for tracking of my robot

ar_track_alvar not precise and not producing repeatebility In my project i am taking a picture from an IP camera and con

following is the snipet of my code i want to change the frequency with which the image is pubished i tried changing the loop_rate(10) to loop_rate(1) but it didn't work

    ros::Rate loop_rate(10);
    int counter =0;
       while(ros::ok() ){
    counter++;
        #if 1
            ros::Time time = ros::Time::now();
            cv_ptr->encoding = "bgr8";
            cv_ptr->header.stamp = time;

cv_ptr->header.frame_id = "/Sufyan_ImageTopic";
        #endif

            cv_ptr->image = image;
            image_pub_.publish(cv_ptr->toImageMsg());

            ROS_INFO("ImageMsg Send.");
        #endif

        }   

    ros::spin();

changing the frequency of loop following is the snipet of my code i want to change the frequency with which the image is

i am using ar track alvar to recieve co ordinates from my camera... The data seems to be fine but i want to use this data.For this i made a subscriber as below

start = (0,0) 

def callback(msg):
    x=msg.pose.position.x
    y=msg.pose.position.y
    rospy.loginfo(rospy.get_caller_id() + "I heard x = %f", x)
    rospy.loginfo(rospy.get_caller_id() + "I heard  y= %f", y)XPos1 =x
    YPos1 =y  
    XPos1 += 0.11
    YPos1 += 0.1
    XPos1 = XPos1 * 22.69
    YPos1 = YPos1 * 24
    XPos1 = round(XPos1) -1
    YPos1 = round(YPos1) 
    XPos1 =int(XPos1)
    YPos1= int(YPos1)    
    start = (XPos1,YPos1)
    print start


print start

where start is a global variable which i initialize in the begining as start(0,0) but when my code is executed even though this call back function is invoked as i can see the value of x and y on terminal and the value of start ( which is a global variable) is also what i expected but as soon as the program exits callback function the the last print statement prints (0,0) as the value of start (which is what i initialized start variable to in the begining of program as global variable) This is the Output

[INFO] [1535398460.244633]: /listener_11195_1535398438793I heard x = 1.294724
[INFO] [1535398460.250098]: /listener_11195_1535398438793I heard  y= -0.089722

(31, 0)
^C(0, 0)

Yes you are right it solved the problem. Thanks a lot!!!

Callback function not changing the value of Global variable i am using ar track alvar to recieve co ordinates from my ca

Callback function not changing the value of Global variable i am using ar track alvar to recieve co ordinates from my ca

Callback function not changing the value of Global variable i am using ar track alvar to recieve co ordinates from my ca

Callback function not changing the value of Global variable i am using ar track alvar to recieve co ordinates from my ca

actually i do have an ultrasonic Sensor mounted in front of my vehicle but it's just to detect if any dynamic obstacle c

Thanks a Lot!!! i have already inflated the area around the obstacle so as to avoid collision... i was also wondering if

Can i Use navigation stack if my robot does not have any laser or kinect type camera currently I am working on a project