Speed Ramping

Well it worked. I don't know why making ServoSpeed(D0, 2) and ServoSpeed(D1, 2) made it work but it did perfectly. This speed made it ramp beautifully.

:D

Thanks DJ on the short fix and thanks Rich on helping me understand code better.

Ellis

Can I start this Sabertooth ramping script with a simple call script and without installing or useing a custom movement panel? Seems that I would have to insert into the call script everything shown in the custom Movement Panel script above and set the proper $motor1speed variable speed I what to achieve.

I looks like the ramping script needs to know the final top spèed and the $motor1speed variable sets that. Does the custom Movement Panel do that in the background?

@Dave Schulpius,

Weren't you the one who posted in the thread where this started (Gwen's halloween thread) that you could set the Sabertooth to automatically ramp through Describe software? I haven't hooked mine up yet, but that sounded like an ideal solution for Sabertooth.

Alan

Set the speed ramping going by first setting the speed for the motor (or motors) then call the ramping script to start. You needn't use the movement panel.

For example, if you had a script for moving a turret clockwise you would just need this (which is in the custom Movement Panel - so yes, this is done in the background);

# Set the required end speed for motor 1
$motor1speed_end = 1

# Start the ramping script going
ControlCommand("Movement Controls", ScriptStart, "Ramp Speed")

When the script is run it will start the motor moving in the direction specified and ramp up to the speed specified. Once it's up to speed it will continue moving until told otherwise.

If it was for a sequence where it would ramp up to a speed, move for 10 seconds then ramp down to stopping you would need this;

# Set the required end speed for motor 1
$motor1speed_end = 1

# Start the ramping script going
ControlCommand("Movement Controls", ScriptStart, "Ramp Speed")

# Sleep for 10 seconds
Sleep(10000)

# Set the required end speed for motor 1
$motor1speed_end = 63

# Start the ramping script going
ControlCommand("Movement Controls", ScriptStart, "Ramp Speed")

@Alen, Yes, I think it was me that said that. I was repeating what i read and was told by Dimension Engineering. I've never tried it though on just a Sabertooth.

@Rich, You're a jewel. Thanks for the clarity on the code. So what I hear you saying is all I need to do is send a version of your $motor1speed_end = 1 to bring the motor up to the wanted speed. I see by your scripts that changing the "1" to the value the controller is looking for is what I need to do and the motor will ramp up (and of course adjusting the Delay in the ramping script)?

However my application is a bit different than running two motors for wheels attached to a sabertooth. I'm using a DC motor on the elbow of my B9 Robot arm and have a Pot attached to it for feedback. I'm controlling it's speed and position with a Kangaroo x2 attached to the Sabertooth. DE's Kangaroo X2 does all the work figuring all this out but when it's in Independent Position mode like I'm using it there is no ramping.

I'm trying to rewrite your ramping script to give the Sabertooth a smoother start up. I'm sending Simple Serial commands through the Kangaroo connected to the Sabertooth through EZB's Uart port for the arm's up and down movement. DE says I can place a command loop like your script to ramp the speed so I thought I'd give it a try.

Here's the proper command to send through EZB's Uart port to have the Sabertooth/Kangaroo combo move one motor on it's channel 1 to a wanted position at a wanted speed:

uartWrite(1, 0, "1, p1800 s400", 0x0d)

Here's the code I have so far (thanks to Rich) . I have mixed results with it. I can get the motor to move to position and at the speed I want but haven't been able to get any ramping. I Plan to keep playing with it and have high hopes. Anyone feel free to jump with suggestions.

Thanks! Dave

$rampdelay = 30 # Adjust to suit speed increase

# Check the direction of ramping up or down and set the steps to suit
IF ($motor1speed < $motor1speed_end)
  # If true motor speed needs to increase therefore +1
  $motor1steps = 1
ELSE 
  # Otherwise it needs to decrease therefore -1
  $motor1steps = -1
ENDIF 
  
REPEATUNTIL($motor1speed = $motor1speed_end)
  # This section will now loop from the above REPEATUNTL down to
  # ENDREPEATUNTIL until the above statement is true
  # (until motor speeds match those required).
  
  # Movement command
  
  # Uart - Serial Control Method (Sabertooth/Kangaroo)
UARTWrite(0, 0, "1, P"+$Moror1positon, "S"+$motor1speed, 0x0d)
  
  IF ($motor1speed = $motor1speed_end)
    # Avoid increasing speed when not needed -
    # in the case of uneven steps between motors.
    # Also state motor up to speed for info.
    Print("Motor1 Up To Speed")
  ELSE 
    # Otherwise increase or decrease the motor speed
    $motor1speed = $motor1speed + $motor1steps
  ENDIF  
    
    # Add a slight delay as required (increase/decrease the delay in the variable at the top of the script)
  SLEEP($rampdelay)
ENDREPEATUNTIL