First, PLC controller frequency with servo drive and load speed

Known as the servo drive Pm = 10000Pulse / r, PLC controller issued by the frequency f (puls / s), how to calculate the load shaft speed n (r / s)

1, when the servo motor directly connected to the axis, set the electronic gear than the molecular ratio of the denominator N.

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N = (f * N) / Pm ……….. This formula finds the number of pulses in units of r / s, 1s, divided by the number of pulses required for one revolution = 1s.

N: load speed, unit: r / s.

F: the frequency of the controller, in units of pls / s.

N: drive electronic gear ratio.

Pm: Servo drive resolution, in Pulse / r.

2, with 1 type, you can reason out when the load shaft with a turntable or pulley, you can calculate the belt speed V.

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V = r * ω = r * 2πn

Push 1 into:

V = πd ((f * N) / Pm)

D: diameter of the pulley, load shaft, in mm.

N: load speed, unit: r / s.

F: the frequency of the controller, in units of pls / s.

N: drive electronic gear ratio.

Pm: Servo drive resolution, in Pulse / r.

3, the scene may encounter the output torque is not enough, plus the reducer of the situation, set the reduction ratio of K.

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By the type 1, already know the motor shaft output speed n, you can get out of the reducer after the output speed n1.

N1 = n / k = (f * N) / (Pm * K) …………… r / s

N1 = n / k = (f * N * 60) / (Pm * K) …………… r / min

Assuming that the n1 axis is with a slider, we can also find the speed at which the slider moves

V = n1 * D = (f * N * D) / (Pm * K) ………… mm / s

Similarly, f = (V * Pm * K) / (N * D)

N: motor straight shaft speed, unit: r / s.

N1: speed of output after reducer, in r / s.

K: Reducer ratio.

V: Speed of movement of the slider, in mm / s.

D: lead lead, unit: mm

Second, the PLC controller output pulse and the relationship between the displacement

With some of the above, we will discuss the following:

As shown in the following figure, we know that the servo drive Pm = 10000Pulse / r, lead screw lead (thread spacing, can be understood as a motor to turn a lead screw to take a lead) for the D, PLC controller issued by the number of pulses P, assuming that the electronic gear ratio is 1.

How to find the distance of the corresponding table to move S?

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4, S = (D / Pm) * P … first find a pulse to go the displacement, multiplied by the number of pulses to get the distance moving. If the electronic gear ratio N is set, S = (D / Pm) * P * N …. Since P * N is the actual pulse sent by the servo drive to the motor.

D: lead lead, unit: mm

P: Number of pulses sent by the controller, in units of units

If the following system is how to calculate the distance of the move? The mechanical part of the system is equipped with the speed reduction ratio of the reducer.

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5, S = (D / (Pm * K)) * P * N Similarly, the same 4 to find a pulse to go the displacement, due to the reducer, a pulse displacement reflected to the load Shaft is smaller than 4 above. It can be seen that the displacement is inversely proportional to the gear structure of the system reducer and is proportional to the servo-driven electronic gear ratio.

According to the above formula, the same reason can also be inferred if it is with a disc structure, the number of pulses corresponding to the angle of rotation of the disc. Equivalent to D = 360 degrees.

The above 4,5 mentioned “first to find a pulse to go the displacement” is actually the legendary pulse equivalent δ.

Third, on the pulse equivalent δ

From 4 and 5, it can be seen that (D / Pm) is the pulse equivalent of the non-reducer, and D / (Pm * K) is the pulse equivalent of the system. It can be seen that if the mechanical structure is determined, this value is also determined, a pulse corresponding to the displacement is determined, that is, the accuracy of the system is determined. Such as 5mm lead screw, with the billion-dimensional servo drive directly connected, the accuracy of 5 / 10000mm. This system has a pulse equivalent of 5 / (10000 * 40) mm if the gearbox with a reduction ratio of 40 is external. The above determined parameters are called the system’s intrinsic pulse equivalent.

Suppose you need to adjust the system precision to 1um / pls. What needs to be done? At this time the servo-driven electronic gear ratio came in handy.

Use the following formula to find:

1: 5 * 1000 / (10000 * 40) = 1: 1/80 = 80: 1 The electronic gear ratio of the Vega US100 servo drive is set to 80 and the denominator P1-01 is set to 1.