joint_.setCommand(commanded_effort) in the joint_position_controller

asked 2019-04-18 14:25:20 -0600

steradiant
29 ●9 ●10 ●14

updated 2019-04-19 14:30:48 -0600

jayess
6155 ●26 ●85 ●92

Hello, I'm looking through the code of ros_control right now to get a deeper understanding how all that stuff works. In my opinion, I got quite far but now I'm stuck. I'm analyzing the effort_controllers/src/joint_position_controller.cpp at the moment. And in line 217 I found this:

joint_.setCommand(commanded_effort);

The steps before are clear, you publish to the topic, the error is computed, then the effort is computed and then it seems to be sent to the joint but when I look into the setCommand in hardware_interface/include/hardware_interface/joint_command_interface.h, I just find

void setCommand(double command) {assert(cmd_); *cmd_ = command;}

and there is no .cpp file which implements this function. So what is happening here?

edit retag flag offensive close merge delete

Comments

1

Can you please update your question with links to the lines that you're referring to? It makes it easier to follow your question

jayess ( 2019-04-18 16:45:54 -0600 )edit

I've updated my post now. Hope it is kinda clear what I'm asking.

steradiant ( 2019-04-19 13:49:33 -0600 )edit

add a comment

0

answered 2022-04-05 22:11:44 -0600

RyanChen.YLC
44 ●4 ●13 ●15

Hi, I have same question now, but I read the code, and found that command is written into pointer cmd_, and this pointer is defined when the constructor of JointHandle is called.

Then the class, JointHandle, will be registered, so I think this is the way that controller builds connection with the hardware interface.

I'm not sure what I said above is correct, but I think it may help.

edit flag offensive delete link

add a comment

0

answered 2019-04-19 14:35:08 -0600

jayess
6155 ●26 ●85 ●92

updated 2019-04-19 14:36:42 -0600

That is the implementation of the setCommand method. It's just written on one line. Maybe it'll be clearer if it's separated out onto multiple lines

void setCommand(double command)
{
    assert(cmd_);
    *cmd_ = command;
}

Many times, if a method is short, it's implementation is left in a header (*.h) file.

edit flag offensive delete link

Comments

The command is set to where cmd_ points to. But I wasn't able to dig deeper whats happening with this cmd_

steradiant ( 2019-04-20 00:17:34 -0600 )edit

add a comment

joint_.setCommand(commanded_effort) in the joint_position_controller

Comments

2 Answers

Comments

Question Tools

Stats

Related questions

joint_.setCommand(commanded_effort) in the joint_position_controller edit

Comments

2 Answers

Comments

Question Tools

Stats

Related questions

joint_.setCommand(commanded_effort) in the joint_position_controller