优化机器人循环时间
To minimize robot cycle time in piece picking, overlap the camera's capture and processing time with the robot's place motion instead of making the robot wait for the vision system. Choose the strategy below that matches your camera mounting.
Stationary Mounting
对于相机是固定安装的拾取和放置应用，我们建议在机器人拾取物体并移动到相机 FOV 之外后再进行捕获。通过该策略，您有可能无需停止机器人即可使用相机捕获图像，具体取决于以下哪个操作需要更长的执行时间：
总捕获时间以及处理数据以检测对象和估计拾取位姿的时间。
机器人从相机FOV外的位姿运动到放置位姿，然后回到再次进入相机FOV之前的位姿的时间。
如果机器人运动的时间更长，则机器人将不必停下来等待。但是，如果前者（捕获+检测+位姿估计）执行时间更长，机器人将不得不停止。查看下面的实施示例。
#include <Zivid/Zivid.h>
#include <future>
#include <iostream>
namespace
{
struct DummyRobot
{
void Move(Zivid::Matrix4x4 pose, std::chrono::milliseconds duration)
{
std::this_thread::sleep_for(duration);
}
};
DummyRobot robot;
Zivid::Matrix4x4 captureAndProcess(Zivid::Camera &camera)
{
const auto settings = Zivid::Settings{ Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} } };
const auto frame = camera.capture(settings);
const auto pointCloud = frame.pointCloud();
const auto data = pointCloud.copyData<Zivid::PointXYZColorRGBA_SRGB>();
const auto pickPose =
Zivid::Matrix4x4{}; // This is where you should run your processing to get a pick pose from the point cloud
return pickPose;
}
void placeObject()
{
const auto placePose = Zivid::Matrix4x4{};
robot.Move(placePose, std::chrono::milliseconds(2000));
const auto outOfCameraFOV = Zivid::Matrix4x4{};
robot.Move(outOfCameraFOV, std::chrono::milliseconds(1000));
}
} // namespace
int main()
{
try
{
Zivid::Application zivid;
auto camera = zivid.connectCamera();
auto pickPose = captureAndProcess(camera);
while(true)
{
std::cout << "Picking the new object" << std::endl;
robot.Move(pickPose, std::chrono::milliseconds(2000));
std::cout << "Object picked" << std::endl;
std::cout << "Moving the robot with a picked object outside the FOV of the stationary camera" << std::endl;
const auto outOfCameraFOV = Zivid::Matrix4x4{};
robot.Move(outOfCameraFOV, std::chrono::milliseconds(2000));
// At this moment the robot should be outside the camera FOV
std::cout
<< "Starting, at the same time (in two threads), robot motion to place the object and capturing and processing to get the new pick pose"
<< std::endl;
auto futurePickPose = std::async(std::launch::async, captureAndProcess, std::ref(camera));
auto placingCompleted = std::async(std::launch::async, placeObject);
pickPose =
futurePickPose
.get(); // This (capturing and processing to get the new pick pose) should be faster so the robot would not have to stop and wait
placingCompleted.get();
std::cout
<< "Both robot motion to place the object and capturing and processing to get the new pick pose completed"
<< std::endl;
}
}
catch(const std::exception &e)
{
std::cerr << "Error: " << Zivid::toString(e) << std::endl;
return EXIT_FAILURE;
}
}
防止机器人停止的替代方法是，对于每个循环，机器人都采用从前一个循环计算出的拾取位姿。此策略允许您在机器人拾取对象时继续处理数据。在这种情况下，在放置对象时，您可以仅进行捕获图像，或者捕获图像并获取点云，以及将其复制到CPU内存中。查看下面的实施示例。该策略假设始终可以估计多个拾取位姿。它还假定当前循环中要拾取的对象在上一个拾取循环中没有移动。确保当前拾取周期中的对象与上一个循环中拾取的对象位于容器的不同区域。这样的对象选择将增加成功拾取的机会。
#include <Zivid/Zivid.h>
#include <future>
#include <iostream>
namespace
{
struct DummyRobot
{
void Move(Zivid::Matrix4x4 pose, std::chrono::milliseconds duration)
{
std::this_thread::sleep_for(duration);
}
};
DummyRobot robot;
Zivid::Frame captureInThread(Zivid::Camera &camera)
{
const auto settings = Zivid::Settings{ Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} } };
const auto frame = camera.capture(settings);
return frame;
}
void placeObjectInThread()
{
const auto placePose = Zivid::Matrix4x4{};
robot.Move(placePose, std::chrono::milliseconds(2000));
const auto outOfCameraFOVPose = Zivid::Matrix4x4{};
robot.Move(outOfCameraFOVPose, std::chrono::milliseconds(1000));
}
Zivid::Matrix4x4 computePickPoseInThread(const Zivid::Frame &frame)
{
const auto pointCloud = frame.pointCloud();
const auto data = pointCloud.copyData<Zivid::PointXYZColorRGBA_SRGB>();
// If you know your robot motion to place the object is slow enough, you can move the above two lines to captureInThread
// This is where you should run your processing to get a pick pose from the point cloud
return Zivid::Matrix4x4{};
}
} // namespace
int main()
{
try
{
Zivid::Application zivid;
auto camera = zivid.connectCamera();
std::cout << "Moving the robot with a picked object outside the FOV of the stationary camera" << std::endl;
const auto outOfCameraFOV = Zivid::Matrix4x4{};
robot.Move(outOfCameraFOV, std::chrono::milliseconds(2000));
// At this moment the robot should be outside the camera FOV
std::cout
<< "Starting, at the same time (in two threads), robot motion to place the object and capturing the point cloud"
<< std::endl;
auto futureFrame = std::async(std::launch::async, captureInThread, std::ref(camera));
auto placingCompleted = std::async(std::launch::async, placeObjectInThread);
const auto frame =
futureFrame
.get(); // This (capturing the point cloud) should be faster so the robot would not have to stop and wait
placingCompleted.get();
std::cout << "Both robot motion to place the object and capturing the point cloud completed" << std::endl;
std::cout << "Starting the processing (in a separate thread) to get the pick pose for the next cycle"
<< std::endl;
auto nextPickPose = std::async(std::launch::async, computePickPoseInThread, frame);
std::cout
<< "Picking the object from the previous pick cycle (becasue computing the pick new pose is not completed yet at this moment)"
<< std::endl;
const auto previousCyclePickPose = Zivid::Matrix4x4{};
robot.Move(previousCyclePickPose, std::chrono::milliseconds(2000));
std::cout << "Object picked" << std::endl;
}
catch(const std::exception &e)
{
std::cerr << "Error: " << Zivid::toString(e) << std::endl;
return EXIT_FAILURE;
}
}
On-Arm Mounting
对于相机安装在手臂上的3D拾取和放置应用，我们建议在机器人拾取物体后进行捕获。使用此策略，机器人只需要在采集时间内停止。一旦采集完成，即捕获API返回时，机器人就可以开始执行放置对象的动作。同时，可以开始为获取下一个循环拾取位姿的点云处理。查看下面的实施示例。
备注
为了优化速度，可以在捕获函数返回之后和调用API获取点云之前移动机器人。
#include <Zivid/Zivid.h>
#include <future>
#include <iostream>
namespace
{
struct DummyRobot
{
void Move(Zivid::Matrix4x4 pose, std::chrono::milliseconds duration)
{
std::this_thread::sleep_for(duration);
}
};
DummyRobot robot;
Zivid::Matrix4x4 computePickPose(const Zivid::Frame &frame)
{
const auto pointCloud = frame.pointCloud();
const auto data = pointCloud.copyData<Zivid::PointXYZColorRGBA_SRGB>();
// This is where you should run your processing to get a pick pose from the point cloud
return Zivid::Matrix4x4{};
}
void placeObject()
{
const auto placePose = Zivid::Matrix4x4{};
robot.Move(placePose, std::chrono::milliseconds(2000));
const auto outOfCameraFOVPose = Zivid::Matrix4x4{};
robot.Move(outOfCameraFOVPose, std::chrono::milliseconds(1000));
}
} // namespace
int main()
{
try
{
Zivid::Application zivid;
auto camera = zivid.connectCamera();
std::cout << "Moving the robot mounted camera to the capture pose" << std::endl;
const auto capturePose = Zivid::Matrix4x4{};
robot.Move(capturePose, std::chrono::milliseconds(2000));
std::cout << "Capturing frame" << std::endl;
const auto settings = Zivid::Settings{ Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} } };
const auto frame = camera.capture(settings);
std::cout << "Processing to get the first pick pose" << std::endl;
auto pickPose = computePickPose(frame);
while(true)
{
std::cout << "Picking the new object" << std::endl;
robot.Move(pickPose, std::chrono::milliseconds(2000));
std::cout << "Object picked" << std::endl;
std::cout << "Moving the robot mounted camera to the capture pose" << std::endl;
robot.Move(capturePose, std::chrono::milliseconds(2000));
// At this moment the robot should be at the capture pose
std::cout << "Capturing frame" << std::endl;
const auto settings = Zivid::Settings{ Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} } };
const auto frame = camera.capture(settings);
std::cout << "Acquisition completed" << std::endl;
std::cout
<< "Starting, at the same time (in two threads), robot motion to place the object and capturing and processing to get the new pick pose"
<< std::endl;
auto futurePickPose = std::async(std::launch::async, computePickPose, frame);
auto placingCompleted = std::async(std::launch::async, placeObject);
pickPose =
futurePickPose
.get(); // This (processing to get the new pick pose) should be faster so the robot would not have to stop and wait
placingCompleted.get();
std::cout
<< "Both robot motion to place the object and capturing and processing to get the new pick pose completed"
<< std::endl;
}
}
catch(const std::exception &e)
{
std::cerr << "Error: " << Zivid::toString(e) << std::endl;
return EXIT_FAILURE;
}
}
小技巧
如果您执行的是2D捕获而不是3D捕获，建议采用相同的策略。但是，如果您同时需要2D和3D数据，那么建议您查看我们的 2D+3D捕获策略 。
如果放置物体的机器人运动快于获取下一个循环拾取位姿的点云处理过程，则机器人将不得不等待。
防止机器人停止的替代方法是，对于每个循环，机器人都采用从前一个循环计算出的拾取位姿。此策略允许您在机器人拾取对象时继续处理数据。查看下面的实施示例。该策略假设始终可以估计多个拾取位姿。它还假定当前循环中要拾取的对象在上一个拾取循环中没有移动。确保当前拾取周期中的对象与上一个循环中拾取的对象位于容器的不同区域。这样的对象选择将增加成功拾取的机会。
#include <Zivid/Zivid.h>
#include <future>
#include <iostream>
namespace
{
struct DummyRobot
{
void Move(Zivid::Matrix4x4 pose, std::chrono::milliseconds duration)
{
std::this_thread::sleep_for(duration);
}
};
DummyRobot robot;
Zivid::Array2D<Zivid::PointXYZColorRGBA_SRGB> getPointCloudInThread(const Zivid::Frame &frame)
{
const auto pointCloud = frame.pointCloud();
const auto data = pointCloud.copyData<Zivid::PointXYZColorRGBA_SRGB>();
return data;
}
void placeObjectInThread()
{
const auto placePose = Zivid::Matrix4x4{};
robot.Move(placePose, std::chrono::milliseconds(2000));
const auto outOfCameraFOVPose = Zivid::Matrix4x4{};
robot.Move(outOfCameraFOVPose, std::chrono::milliseconds(1000));
}
Zivid::Matrix4x4 computePickPoseInThread(const Zivid::Array2D<Zivid::PointXYZColorRGBA_SRGB> &data)
{
// This is where you should run your processing to get a pick pose from the point cloud
return Zivid::Matrix4x4{};
}
} // namespace
int main()
{
try
{
Zivid::Application zivid;
auto camera = zivid.connectCamera();
std::cout << "Moving the robot mounted camera to the capture pose" << std::endl;
const auto capturePose = Zivid::Matrix4x4{};
robot.Move(capturePose, std::chrono::milliseconds(2000));
// At this moment the robot should be at the capture pose
std::cout << "Capturing frame" << std::endl;
const auto settings = Zivid::Settings{ Zivid::Settings::Acquisitions{ Zivid::Settings::Acquisition{} } };
const auto frame = camera.capture(settings);
std::cout << "Acquisition completed" << std::endl;
std::cout
<< "Starting, at the same time (in two threads), robot motion to place the object and waiting for the point cloud to be processed and copied"
<< std::endl;
auto futureData = std::async(std::launch::async, getPointCloudInThread, frame);
auto placingCompleted = std::async(std::launch::async, placeObjectInThread);
const auto data =
futureData
.get(); // This (remaining time to process the point cloud) should be faster so the robot would not have to stop and wait
placingCompleted.get();
std::cout << "Both robot motion to place the object and point cloud processing and copying completed"
<< std::endl;
std::cout << "Starting the processing (in a separate thread) to get the pick pose for the next cycle"
<< std::endl;
auto nextPickPose = std::async(std::launch::async, computePickPoseInThread, data);
std::cout
<< "Picking the object from the previous pick cycle (becasue computing the pick new pose is not completed yet at this moment)"
<< std::endl;
const auto previousCyclePickPose = Zivid::Matrix4x4{};
robot.Move(previousCyclePickPose, std::chrono::milliseconds(2000));
std::cout << "Object picked" << std::endl;
}
catch(const std::exception &e)
{
std::cerr << "Error: " << Zivid::toString(e) << std::endl;
return EXIT_FAILURE;
}
}
在下一章节中，我们将介绍我们建议执行的机器视觉过程来帮助您 准备好使您的Zivid相机用于生产 。