Adaptivecontrol
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Adaptive control machining systems, including NC, CNC, and DNC, utilize feedback from various machining process variables to optimize operations and minimize non-productive time. The adaptive controller adjusts speed and feed based on factors such as spindle deflection, cutting temperature, and material properties, which enhances efficiency and reduces costs. Key applications include scenarios with significant in-process time variability, where improved tool life, production rates, and operator involvement are achieved.
Adaptivecontrol
- 1. Adaptive Control Machining systems
- 2. NC, CNC and DNC
- 3. 1.The adaptive control feedback provides sensory information on machining process variables such as 1.Spindle deflection or force, 2.Torque, 3.Cutting temperature, 4.Work piece tool air gaps, 5.Material property variations, 6.Vibration amplitude, 7.Metal removable rate cost per volume of metal removed 8.Horsepower. 2. The data is processed by an adaptive controller that converts the process information into feedback data to be incorporated into the machine control unit
- 5. 1. The main advantage of NC/CNC is that reduces the non- productive time in machining operation. 2. This time saving is achieved by reducing work piece handling time , set-up of the job, Tool changes , and other source of operator and machine delay. 3. The NC/CNC controls the sequence of tool positions during machining. 4. There is every possibility of spindle deflection or increasing of cutting temperature, or work piece tool air gaps, or material property variations or machine tool vibration, this process parameters waste production time 5. The most promising means of reducing the productive time is the USE OF ADAPTIVE CONTROL 6. AC determines proper speed and feed during machining as functions of variations in process variables such as Work-material hardness ,width or depth cut , air gaps in the part geometry
- 6. Adaptive Control A control system that measures certain output process variables like spindle deflection, force, torque, cutting temperature, vibration amplitude, horse power and uses them to control speed or feed NC reduces non productive time in a machining operation. AC determines proper speeds and feeds during machining as a function of variation in work piece hardness, width or depth of cut, air gaps in part geometry etc. Increased metal removal rate and reduced cost per volume of metal removed
- 7. Where to use adaptive control? Application: 1. In-process time consumes significant portion of the machining cycle time. (>40%) 2. Significant sources of variability in the job 3. Higher cost of operation of machine tool 4. Work material – steel, titanium, high strengh alloys
- 8. Sources of variability in machining 1. Variable depth/width of cut 2. Variable workpiece hardness and variable machinability 3. Variable workpiece rigidity 4. Toolwear 5. Air gaps during cutting
- 10. Types of Adaptive controls 1. Adaptive control Optimisation (ACO) 2. Adaptive control Constraint (ACC)
- 11. Adaptive Control Optimization (ACO) Index of performance is a measure of overall process performance such as production rate or cost per volume of metal removed. Objective is to optimize the index of performance by manipulating speed or feed in the operation IP = MRR/TWR MRR – Material removal rate TWR – Tool wear rate Sensors for measuring IP not available
- 13. Adaptive control Constraint (ACC) Nearly all AC systems is of this type Less sophisticated and less expensive than research ACO systems Objective is to manipulate speed or feed so that measured process variables are maintained at or below their constraint limit values.
- 15. Operation of ACC system Profile or contour milling on NC machine tool Feed is controlled variable Cutter force and horsepower are used as measured variables Hardware components 1. Sensors mounted on the spindle to measure cutter force 2. Sensors to measure spindle motor current 3. Control unit and display panel to operate the system 4. Interface hardware to connect the AC system to existing NC/CNC system
- 16. Relationship of AC software to APT program
- 17. Operation of ACC system during machining process
- 18. Benefits of AC 1. Increased production rate 2. Increased tool life 3. Greater part protection 4. Increases machine life 5. Less operator intervention 6. Easier part programming