Method 1: Characteristic curve a(n) in polynomial- or hyperbola form
In the range above the limit speed, the current acceleration is optionally specified by a third-order polynomial or by a hyperbola function. In the case of both characteristics, a constant acceleration akonst is used in the range below ngrenz. This corresponds to acceleration at nominal speed. The curves apply to both the speed build-up and slow-down phases.
Interpolation points on the drive curve a(n) are used to determine the coefficients of the curves. 4 or 3 interpolation points are required to determine them.
One interpolation point P1=(n1, (a(n1)) is already defined by the parameter for constant acceleration akonst and the limit speed ngrenz and the user can define the remaining 3 or 2 on the drive characteristic a(n). It is best for the abscissa values to be at a constant distance. The equations to determine the coefficients are listed below.
Polynomial
, relative speed
Example of curve determination
Interpolation point | Acceleration a [°/s2] | Speed n [°/s] |
1 | 16000 | 12000 |
2 | 8000 | 24000 |
3 | 4000 | 36000 |
4 | 2000 | 48000 |
aconst = 16000 [°/s2] to nlimit = 12000 [°/s]
The following is obtained for the coefficients:
b3 = -1.92901234E-10 [s/°2]
b2 = 2.08333333E-5 [1/°]
b1 = -0.88888888 [1/s]
b0 = akonst = 16000 [°/s2]
As from nominal speed (nlimit) the characteristic profile is as follows::
Hyperbola
, normalised speed,
Example of curve determination
Interpolation point | Acceleration a [°/s2] | Speed n [°/s] |
1 | 16000 | 12000 |
2 | 8000 | 24000 |
3 | 4000 | 36000 |
4 | 2000 | 48000 |
A_konstkonst = 16000[degrees/s2] to nlimit = 12000 [degrees/s]
The following is obtained for the coefficients:
b2 = 4.166666E-1[]
b3 = 2.857142E-2[]
b1 = 2.285714E4[°/s2]
As from nominal speed (nlimit) the characteristic profile is as follows::
Parameter
Type: 1 (hyperbola) or 2 (polynomial) | |
Limit speed nlimit | |
Constant acceleration aconst for n<nlimit | |
Minimum acceleration amin | |
Coefficient b1 | |
Coefficient b2 | |
Coefficient b3 |
Parameterisation examples
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beschl_kennlinie.typ 1 Hyperbola shape
beschl_kennlinie.a_min 1400 [°/s*s]
beschl_kennlinie.n_grenz 12000000 [10-3 °/s]
beschl_kennlinie.a_konst 16000 [°/s*s]
beschl_kennlinie.b1 2.285714E4 [°/s*s]
beschl_kennlinie.b2 4.166666E-1 []
beschl_kennlinie.b3 -2.857142E-2 []
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beschl_kennlinie.typ 2 Polynomial shape
beschl_kennlinie.a_min 2000 [°/s*s]
beschl_kennlinie.n_grenz 12000000 [10-3 °/s]
beschl_kennlinie.a_konst 16000 [°/s*s]
beschl_kennlinie.b1 -0.88888888 [1/s]
beschl_kennlinie.b2 2.08333333E-5 [1/°]
beschl_kennlinie.b3 -1.92901234E-10 [s/°²]
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