Real-Time Tuning 2 (Rapid Traverse Time Constant); Outline - Mitsubishi Electric M800VW Series Programming Manual

M800V/M80V Series PLC Programming Manual (2/2)
14 PLC Help Function

14.30 Real-Time Tuning 2 (Rapid Traverse Time Constant)

14.30 Real-Time Tuning 2 (Rapid Traverse Time Constant)

14.30.1 Outline

This function estimates the inertia of workpiece and optimizes the operation acceleration/deceleration time constant
automatically according to the estimation results. This allows the cycle time to be reduced when the inertia of workpiece
fluctuates considerably.
This function is useful when the inertia of workpiece fluctuates considerably during machining as illustrated in Example 1:
Indexing machining and Example 2: Workpiece replacement on the rotary table below.
In Example 1, the inertia of workpiece is reduced gradually as machining progresses. In Example 2, the inertia of workpiece
on the rotary table is reduced by workpiece replacement. When the inertia of workpiece is large in Example 1 or Example 2,
the machine tool is required to be operated at a low acceleration to suppress the vibration for the workpiece and overload for
the motor. On the other hand, when the inertia of workpiece is smaller, the operation at a higher acceleration is available. In
other words, acceleration/deceleration time constant can be reduced when the inertia of workpiece is smaller.
In the existing specifications, the operation acceleration/deceleration time constant is fixed regardless of the inertia of
workpiece, which wastes time because a large time constant is applied even if the inertia of workpiece is small.
This function enables the operation with optimum acceleration/deceleration time constant according to the inertia of the
workpiece. Therefore, machining is performed while reducing the acceleration/deceleration time constant in Example 1 or
Example 2, which leads to a shorter tact time.
Furthermore, the large inertia workpiece is not machined with small acceleration/deceleration time constant since the
optimum time constant is adjusted automatically. This enables suppression of vibration and overload.
Time is wasted because
acceleration/deceleration time constant is fixed
Example1: Indexing machining
Machining
Example2: Workpiece replacement
Replacement
Speed waveform
Speed
Current waveform
Current
IB-1501668-B
Existing
Time
Varying load
Time
Real-time tuning 2
Cycle time can be reduced because
acceleration/deceleration time constant is
changed
Example1: Indexing machining
Machining
Example2: Workpiece replacement
Replacement
Speed waveform
Speed
Current waveform
Current
Constant load
774
Time
Time can be reduced
Time