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First commit for diff-drive robot (#174) #175

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1 change: 1 addition & 0 deletions CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -163,6 +163,7 @@ FILE(GLOB SRCS src/bitrl/*.cpp
src/bitrl/planning/*.cpp
src/bitrl/rigid_bodies/*.cpp
src/bitrl/rigid_bodies/chrono_robots/*.cpp
src/bitrl/rigid_bodies/chrono_robots/impl/*.cpp
src/bitrl/rigid_bodies/webots_robots/*.cpp
src/bitrl/dynamics/*.cpp
src/bitrl/utils/*.cpp
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106 changes: 37 additions & 69 deletions examples/example_13/example_13.cpp
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Expand Up @@ -12,6 +12,7 @@

#include "chrono/core/ChRealtimeStep.h"
#include "chrono/physics/ChSystemNSC.h"
#include <chrono/physics/ChBodyEasy.h>
#include "chrono/physics/ChLinkMotorRotationSpeed.h"
#include <chrono_irrlicht/ChVisualSystemIrrlicht.h>

Expand All @@ -32,7 +33,7 @@ const real_t DT = 0.01;
const real_t SIM_TIME = 5.0;
const std::string WINDOW_TITLE( "Example 13");

void prepare_visualization(chrono::irrlicht::ChVisualSystemIrrlicht& visual)
/*void prepare_visualization(chrono::irrlicht::ChVisualSystemIrrlicht& visual)
{
visual.SetWindowSize(WINDOW_WIDTH, WINDOW_WIDTH); //WINDOW_HEIGHT);
visual.SetWindowTitle(WINDOW_TITLE);
Expand All @@ -43,61 +44,46 @@ void prepare_visualization(chrono::irrlicht::ChVisualSystemIrrlicht& visual)
visual.AddCamera({0, -2, 1}, {0, 0, 0});
visual.AddTypicalLights();
visual.BindAll();
}
}*/


/*class DiffDriveRobot
{
public:

DiffDriveRobot();

void set_motor_speed(real_t rad_speed, uint_t id);

/// Get active drive wheel speed
chrono::ChVector3d get_wheel_speed(uint_t id);

/// Get active driver wheel angular velocity
chrono::ChVector3d get_wheel_angular_velocity(uint_t id);



};*/

} // namespace example_13

int main()
{
using namespace example_13;
/* using namespace example_13;
chrono::ChSystemNSC sys;
sys.SetGravityY();

// 2- Create the rigid bodies of the slider-crank mechanical system
// (a crank, a rod, a truss), maybe setting position/mass/inertias of
// their center of mass (COG) etc.

// ..the truss
auto my_body_A = chrono_types::make_shared<chrono::ChBody>();
sys.AddBody(my_body_A);
my_body_A->SetFixed(true); // truss does not move!
my_body_A->SetName("Ground-Truss");

// ..the crank
auto my_body_B = chrono_types::make_shared<chrono::ChBody>();
sys.AddBody(my_body_B);
my_body_B->SetPos(chrono::ChVector3d(1, 0, 0)); // position of COG of crank
my_body_B->SetMass(2);
my_body_B->SetName("Crank");

// ..the rod
auto my_body_C = chrono_types::make_shared<chrono::ChBody>();
sys.AddBody(my_body_C);
my_body_C->SetPos(chrono::ChVector3d(4, 0, 0)); // position of COG of rod
my_body_C->SetMass(3);
my_body_C->SetName("Rod");

// 3- Create constraints: the mechanical joints between the rigid bodies.

// .. a revolute joint between crank and rod
auto my_link_BC = chrono_types::make_shared<chrono::ChLinkLockRevolute>();
my_link_BC->SetName("RevJointCrankRod");
my_link_BC->Initialize(my_body_B, my_body_C, chrono::ChFrame<>(chrono::ChVector3d(2, 0, 0)));
sys.AddLink(my_link_BC);

// .. a slider joint between rod and truss
auto my_link_CA = chrono_types::make_shared<chrono::ChLinkLockPointLine>();
my_link_CA->SetName("TransJointRodGround");
my_link_CA->Initialize(my_body_C, my_body_A, chrono::ChFrame<>(chrono::ChVector3d(6, 0, 0)));
sys.AddLink(my_link_CA);

// .. a motor between crank and truss
auto my_link_AB = chrono_types::make_shared<chrono::ChLinkMotorRotationSpeed>();
my_link_AB->Initialize(my_body_A, my_body_B, chrono::ChFrame<>(chrono::ChVector3d(0, 0, 0)));
my_link_AB->SetName("RotationalMotor");
sys.AddLink(my_link_AB);
auto my_speed_function = chrono_types::make_shared<chrono::ChFunctionConst>(chrono::CH_PI); // speed w=3.145 rad/sec
my_link_AB->SetSpeedFunction(my_speed_function);
sys.SetGravitationalAcceleration(chrono::ChVector3d(0, 0, -9.81));

sys.SetCollisionSystemType(chrono::ChCollisionSystem::Type::BULLET);
chrono::ChCollisionModel::SetDefaultSuggestedEnvelope(0.0025);
chrono::ChCollisionModel::SetDefaultSuggestedMargin(0.0025);

auto floor_mat = chrono_types::make_shared<chrono::ChContactMaterialNSC>();
auto mfloor = chrono_types::make_shared<chrono::ChBodyEasyBox>(20, 20, 1, 1000, true, true, floor_mat);
mfloor->SetPos(chrono::ChVector3d(0, 0, -1));
mfloor->SetFixed(true);
mfloor->GetVisualShape(0)->SetTexture(chrono::GetChronoDataFile("textures/concrete.jpg"));
sys.Add(mfloor);


chrono::irrlicht::ChVisualSystemIrrlicht visual;
prepare_visualization(visual);
Expand All @@ -123,25 +109,6 @@ int main()
// .. draw GUI items belonging to Irrlicht screen, if any
visual.GetGUIEnvironment()->drawAll();

// .. draw the rod (from joint BC to joint CA)
tools::drawSegment(&visual, my_link_BC->GetMarker1()->GetAbsCoordsys().pos,
my_link_CA->GetMarker1()->GetAbsCoordsys().pos,
chrono::ChColor(0, 1, 0));
// .. draw the crank (from joint AB to joint BC)
tools::drawSegment(&visual, my_link_AB->GetFrame2Abs().GetCoordsys().pos,
my_link_BC->GetMarker1()->GetAbsCoordsys().pos,
chrono::ChColor(1, 0, 0));

// .. draw a small circle at crank origin
tools::drawCircle(&visual, 0.1, chrono::ChCoordsys<>(chrono::ChVector3d(0, 0, 0), chrono::QUNIT));

/* test: delete a link after 10 seconds
if (sys.GetChTime() >10 && (!removed))
{
sys.RemoveLink(my_link_AB);
removed = true;
}*/

// ADVANCE SYSTEM STATE BY ONE STEP
sys.DoStepDynamics(DT);
// Enforce soft real-time
Expand All @@ -151,6 +118,7 @@ int main()
visual.EndScene();
}

*/

return 0;
}
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3 changes: 2 additions & 1 deletion examples/example_13/example_13.md
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Expand Up @@ -10,7 +10,8 @@ A _ChSystem_ is an abstract class. The Chrono library provides the following sub
- _ChSystemSMC_ for SMooth Contacts (SMC): contacts are handled using penalty methods, i.e. contacts are deformable

Note that if there are no contacts or collisions in your system, it is indifferent to use _ChSystemNSC_ or _ChSystemSMC_.
In this example we will create and simulate a differential drive system using Chrono
In this example we will create and simulate a differential drive system using Chrono. The robot we will develop follows the
<a href="https://api.projectchrono.org/group__robot__models__turtlebot.html">Turtlebot robot model</a> defined in Chrono.

@code{.cpp}
@endcode
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