News from the product management: Selecting a naXture actuator for your actuation task

We are starting our blog series to support our customers in selecting our actuators for different actuation tasks.

In line with the product launch, we start with the demo application “Weight Lifting” and go – step by step – from the analysis to the verification of the selection in the force-verlocity map.

Requirements for the work task

Actuation task:

A weight of 40kg has to…

  • be lifted 12mm high
  • reach the end position within 2 seconds
  • hold the position for 1 second

Requirements:

The system has to…

  • be actively driven in one direction
  • automatically return to its initial position
  • to have the safety behaviour „Normally Open“
  • to be able to to lift a load of 50kg
  • reach verlocities of up to 8mm/s

Analysis of the actuation task

1. Creating a force-patch diagram

2. Creating the according path-tim diagram

3. Calculating the load data:

  • Load: FApp = m * g = 40kg * 9,81m/s2400N
  • Stroke: 12mm
  • Time:  t1 = 2s; t2 = 1s
  • Velocity: v1 = 12mm / 2s = 6mm/s

Calculation of the load data

4. Calculation of the work W[J] and the required power P[W]:

  • W = F * s
  • P = F * v = W / t
Stroke
s [mm]
Force
F [N]
Time
t [s]
Velocity
v [mm/s]
Work
W [J]
Power
P [W]
04000000
12400264,82,4
124003000

During the actuation

  • a work W1 of 4,8J is applied
  • a power of 2,4W is required

Selecting the actuator

5. Determine the force FPmax

  • For a first orientation we suggest in our sample tool to pre-select the force Fmax with a 60-65% surcharge on the highest force FApp:
    Fmax = 400N * 1,6 … 1,65 ≈ 640 … 660N
  • Having a look at the force-displacement diagram, it is obvious that the main work is done with 400N. Therefore, in this case, it is better to select FPmax close to FApp , in order to be in range of the optimal power.
  • So we start the selection with: FApp = FPmax = 400N

The selection should start with FPmax = 400N:

The displayed „Best Match“ then results in:

FPmaxFmaxvPmaxvmaxHub
380,00760,0014,0028,0015

Downloading the technical information sheet

6. Downloading the technical information sheet of the actuator:

FPmaxFmaxvPmaxvmaxStroke
380,00760,0014,0028,0015

Verification of the force-velocity map

7. Review your selection in the actuator’s force-velocity map:

The force-verlocity requirements are within the map; the selection is verified.

  • The chosen actuator can perform the work task
  • The next smaller actuator would also be a good choice for F=400N; v=6mm/s.