trapezoidal triangular motion calcs

[Medwar19]

Hi all,

I'm working on a 3-axis cartesian robot project for school and need some help understanding selection concepts.
I created an array of points in 3D space that I want the robot to service so I know the distance and time available for travel for each axis.

The question is knowing the basic equations for motion how do I calculate the minimum velocities needed to achieve my timing?
I know that I can accelerate the robot using trapezoidal or triangular velocity profiles but how do I go about calculating what these should be?
The robot manufacturers I have to choose from only give maximum velocity of each axis, I dont know how quickly they can accelerate. Knowing the path I can calculate the average velocity but that doesn't help me understand how fast the robot will need to go to make up for the accel/decel phases.

Thanks for any help or pointers to information.

Mark.

[Admin]

how do I calculate the minimum velocities needed to achieve my timing?

velocity = distance / time

The robot manufacturers I have to choose from only give maximum velocity of each axis

3D velocity = sqrt(vel_X^2 + vel_Y^2 + vel_Z^2)
the same concept works for acceleration in 3D

I dont know how quickly they can accelerate.

Acceleration is dependent on mass, too. If your robot picks something up, that immediately changes acceleration. If controlling acceleration is important to you, you must use encoders to measure it.

But if you just want to estimate acceleration . . .
force = mass * acceleration
motor_torque = distance * force

solving . . .
motor_torque/(mass*distance) = acceleration

where distance is defined as the moment arm length, from the motor axis to the center of mass of the moving object