Servo Control Buffering for Synchronized Actuation Timing
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Solution Overview
Problem
Existing servo controllers compute control values based on immediate input signals, leading to short delay times that can cause actuator devices to actuate asynchronously, potentially resulting in collisions or interference when shared between manufacturing work machines with different control periods.
Innovation Solution
A servo controller that computes and stores output signals for a time greater than or equal to one period, ensuring consistent delay times across different manufacturing work machines, thereby preventing collisions and allowing for the use of lower computational capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the output signal is computed based on the immediate input signal with short holding time, then the delay time is shortened and the servo motor can actuate responsively, but the computational capability requirement increases and the cost increases
Solution Approach 1:
The patent applies preliminary action by pre-computing control values for multiple future periods and storing them in advance. The computation unit computes control values for a first period, a second period, and a third period sequentially, storing each before the next computation begins. This allows the holding unit to retrieve pre-computed values without requiring rapid real-time computation, thereby reducing the delay time while maintaining manageable computational requirements.
Solution Approach 2:
The patent implements periodic action through sequential computation cycles for multiple periods. The computation unit operates in discrete periodic steps, computing control values for the first period, then the second period, then the third period, with each computation cycle completing before the next begins. This periodic structure breaks down the computational burden into manageable segments while ensuring timely delivery of control values to the holding unit.
2Loss of time
If the control period is shortened to reduce delay time, then the responsiveness improves, but the actuator devices may actuate asynchronously when shared between manufacturing work machines with different control periods
Solution Approach 1:
The patent applies preliminary action by pre-computing and pre-storing control values for multiple future periods before they are needed. The computation unit computes control values for the first period, stores it; then computes for the second period, stores it; then computes for the third period, stores it. This advance preparation ensures that control values are ready when needed, maintaining consistent timing behavior across different manufacturing work machines even when control periods differ, thereby preventing asynchronous actuation.
Solution Approach 2:
The holding unit serves as an intermediary between the computation unit and the drive circuit. It receives pre-computed control values from the computation unit and holds them until the appropriate time for output. This intermediary buffer decouples the computation timing from the output timing, allowing the system to maintain synchronization across different machines with different control periods while still achieving low delay times.
3Loss of time
If the computational capability is increased to compute control values rapidly, then the delay time is reduced, but the cost of the servo controller increases
Solution Approach 1:
The patent applies preliminary action by performing computations in advance and storing results before they are needed. Instead of requiring high-speed real-time computation, the system computes control values for multiple periods sequentially and stores them beforehand. This approach reduces the delay time without requiring expensive high-performance computational hardware, as the computation burden is distributed over time rather than concentrated in real-time.
Solution Approach 2:
The patent uses periodic action to distribute computational tasks across multiple time periods. The computation unit computes control values for the first period, then the second period, then the third period in sequential cycles. This periodic computation strategy reduces the instantaneous computational load, allowing the use of lower-cost, lower-performance processors while still achieving timely control value delivery through the buffering effect of the holding unit.
Data Source
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AI summary
A controller 102 capable of transmitting and receiving an input signal from a drive circuit corresponding to a moving device, a mounting head, or the like of an electronic component mounting machine or an output signal to the drive circuit for each predetermined period (A/2), in which the controller 102 computes an output signal based on an input signal which is received before the predetermined period, stores the output signal for a time greater than or equal to the predetermined period, and subsequently transmits the output signal to the drive circuit. Accordingly, it becomes possible to compute an output signal using a long time, and it becomes possible to adopt a servo controller with low computational capabilities. It becomes possible to set a time (a delay time) from when an input signal is output until an output signal reaches a drive circuit to an arbitrary length by adjusting the storage time. Accordingly, for example, it becomes possible to render the delay times of controllers with different control periods the same, and it becomes possible to render actuation timing or the like of actuator devices of each controller the same.