How to use Reduced Mode in C# or CPP

[Olivier]

Hi All,

I’m developing an app in C# using a class based on the C# Wrapper (XArmAPI.cs).
I want to demonstrate the reduced mode for my students so my computer setup is :

• Detection sensor on serial => in C# event DataReceived
• Loop (x5) Motion between 2 poses where arm should go in reduced mode

I want to see the speed change when the sensor is activated and the flag HumanIn is set to true.

Some pieces of code:
- xARM reset and Max Speed definition

  xARM.Reset();
 xARM.SetReducedMaxTCPSpeed(500.0F);

- Serial event code

// Cobot RS232 Interrupt
if (rs232.StartsWith(“E”))
{
HumanIn = !HumanIn;
if (xARM.IsCreated() && xARM.IsEnableMotion())
{
if (HumanIn)
xARM.ActivateReducedMode(true);
else
xARM.ActivateReducedMode(false);
}
}

As I can’t see the speed changes then I modify my code to test the HumanIn flag state toggle with the code below:

// Loop
if (xARM.IsCreated() && xARM.IsEnableMotion())
{
for (int i = 0; i < 5; i++)
{
if (HumanIn)
i = 5;
xARM.MoveBase(pose1, radius, speed, acc, mvtime, wait, timeout, relative, motion_type);
// Update GUI
buttonGetJoint_Click(sender, e);
buttonGetPosition_Click(sender, e);
xARM.MoveBase(pose2, radius, speed, acc, mvtime, wait, timeout, relative, motion_type);
// Update GUI
buttonGetJoint_Click(sender, e);
buttonGetPosition_Click(sender, e);
}
if (HumanIn)
{
xARM.MoveHome(0, 0, 0, true);
// Update GUI
buttonGetJoint_Click(sender, e);
buttonGetPosition_Click(sender, e);
}
else
{
xARM.MoveBase(pose1, true);
// Update GUI
buttonGetJoint_Click(sender, e);
buttonGetPosition_Click(sender, e);
}
}

The result is OK => the flag goes to true => the loop is stopped => Robot goes to Home

Now to setup the reduced mode, some questions:

Q1) How the setup the “normal” TCP Speed for all “MoveBase” (same as setPosition in XArmAPI )?
In most of the code sample, in setPosition, speed is set to default value = 0.

Q2) Is it possible to enable or disable the Reduced Mode while arm is in motion ?

Regards.
Olivier.

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[Minna]

Hi Olivier,

Q1: you can set a global speed, for example, set the speed in if{humanIn}. If you set a speed greater than the max reduced mode speed, the max reduced mode speed will be used by default after the reduced mode is turned on, we use arm->last_used_tcp_speed.
Q2: No, Reduced mode takes effect for the next command and will not affect the current running movement.

Best regards,
Minna

[Olivier]

Hi Minna,

Ok the reduced mode will be effective for the next move.

I’ve designed my own c# class but basically the same as the wrapper or the C¨++ api.
Below, the setup instructions in the C++ sample for reduced Mode:

XArmAPI *arm = new XArmAPI(port);
sleep_milliseconds(500);
if (arm->error_code != 0) arm->clean_error();
if (arm->warn_code != 0) arm->clean_warn();
arm->motion_enable(true);
arm->set_mode(0);
arm->set_state(0);
sleep_milliseconds(500);

ret = arm->set_reduced_max_tcp_speed(500);
printf(“set_reduced_max_tcp_speed, ret=%d\n”, ret);
ret = arm->set_reduced_max_joint_speed(100);
printf(“set_reduced_max_tcp_speed, ret=%d\n”, ret);

The “normal” speed is not defined in the code.
To demonstrate the reduced mode to my students, I want to setup (in the code) the speed at 1000mm/s and the reduced mode speed is 500mm/s.

Question: should I use the min - max variable to setup the “normal” velocity:

fp32 *tcp_speed_limit; // fp32[2]{min, max}

More testing and results
I’ve put a set_position with speed at 1000mm/s before my loop so arm->last_used_tcp_speed should be at this value.
I’ve reduced the max speed as follow:

ret = arm->set_reduced_max_tcp_speed(100);
ret = arm->set_reduced_max_joint_speed(80);

Now I can visually see the velocity change when the reduced Mode is activate.

But question above is still pending

Regards.

Olivier.

[Minna]

Hi Oliver,

Not quite understand what is the current problem, can you explain more?

I try to explain the logic of speed. When you call set_position, if the defined speed is greater than 0, then it will use the speed you defined. If not, it will use the speed in last_used_tcp_speed.
The initial value of last_used_tcp_speed is 100, and it will be updated if you define speed in set_position, it has nothing to do with tcp_speed_limit.

When you enable and set reduced mode, if you don’t define speed in set_position, and last_used_tcp_speed > reduced_max_tcp_speed, it will use reduced max tcp speed.

Minna

[Olivier]

Hi Minna,

I’ll try to be more precise.
In blockly or in python, you can explicitly define:

• TCP speed and acceleration
• Joint speed and acceleration

I understand that:

• Initial speed value is 100mm/s (default value in the CPP API)
• In set_position if speed = 0 then last_used_tcp_speed is used
• In set_position if speed > 0 then the move will be with the specified velocity (if possible) and last_used_tcp_speed is updated.

Question : I’m looking to do default value initialization in C++or in C# => which variable or function should I change or call ?

With this settings in my code below:

• set_reduced_max_tcp_speed(100)
• set_reduced_max_joint_speed(80)
• set_position to pose0 with speed = 1000mm/s before the loop
• looping pose1 and pose2 with speed = 0 in set_position (to use last_used_tcp_speed)

I could see the TCP speed changes (10 times slower) when entering reduced mode.

The C++ sample with reduced mode is setup with 500mm/s and this value is above the default one of 100mm/s maybe this is why I could not see the velocity changes.

Regards.
Olivier.

        speed = 1000.0F;
        if (xARM.IsCreated() && xARM.IsEnableMotion())
        {
            xARM.MoveBase(pose0, radius, speed, acc, mvtime, wait, timeout, relative, motion_type);
            for (int i = 0; i < 5; i++)
            {
                //if HumanIn is true => Activate Reduced Mode
                xARM.ActivateReducedMode(HumanIn);
                xARM.MoveBase(pose1, radius, 0.0F, acc, mvtime, wait, timeout, relative, motion_type);
                xARM.MoveBase(pose2, radius, 0.0F, acc, mvtime, wait, timeout, relative, motion_type);
            }
            if (HumanIn)
                xARM.MoveHome(0.0F, 0.0F, 0.0F, true);
            else
                xARM.MoveBase(pose1, true);
        }

[Minna]

Hi Olivier,

The C++ sample with reduced mode is setup with 500mm/s and this value is above the default one of 100mm/s maybe this is why I could not see the velocity changes.
→ Yes, I think so.

Actually, for Blockly, we pass the speed ourselves.

For C++, you can initialize via arm->last_used_tcp_speed = xxx; or store the speed in your program and pass it into set_position yourself.

Best,

[Olivier]

Hi Minna,

Yes this is what I’ve seen in Blockly or Python.

I’ll try to initialize last_used_tcp_speed at beginning of my code to force tcp speed above 100mm/s.

Now my program enters in reduced mode when the event is raised for the first time but does not goes back to normal when the event is raised a second time.
I think this is more windows programming and not linked to xARM code.

I’ll report my results.

Thanks for your feedback.

Regards.
Olivier.