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ADCNC Function Reference Manual 2.0 Wei-Li Chuang MAPS-Embedded System Section 1

Revision sheet: Rev Date Author Description 2.0 2014.10.14 Weili Release ADCNC function reference manual MAPS-Embedded System Section 2

1. Introduction The ADCNC library is a hardware-independent library which is developed for the demands of two-dimensional high speed and high precise machining in industry. Figure 1 illustrates the structure of ADLINK CNC system composed of ADCNC library, APS library and motion control card. The ADCNC library including blocks of read file, path optimization and velocity planning plays an important role in this CNC system. The read file block can import user’s CAD/CAM file and the imported data can be processed by both path optimize and velocity planning or only velocity planning. The path optimize block is mainly responsible for line fitting of imported data. It has benefits of reducing machining time but the tradeoff is discontinuity of velocity and acceleration of each axis. The velocity planning block is used to generate smooth resultant velocity profile and acceleration profile for user’s applications. A smooth velocity factor is employed to avoid vibration to improve manufacturing quality. The results of ADCNC library will transfer data to motion control card sequentially by APS library. Finally, the motion control card will generate smooth position commands to each axis to control the servo motor system by interpolation function for various applications. Figure 1 ADLINK CNC system Now each block of ADCNC library will be introduced here. MAPS-Embedded System Section 3

(1) Read file block: An example below shows a basic format of user’s CAD/CAM file being able to recognize by read file block should include items opt (option), x and y (absolute position of axes or arc center) and theta (arc angle). The detailed bit define of opt will be introduced in the description of structure POS_DATA_2D_F64. On the other hand, the absolute position of each axis and arc angle can be floating values. The unit of arc angle is degree and its resolution is 10E-6. For example, if desired angle of arc is 90.0 degree, the input should be 90000000.0. Example of file format for structure POS_DATA_2D_F64 // opt x y theta 0x00000308 0.0000000000 0.0000000000 0.0000000000 0x00000308 -0.0499995833 9.9998333342 0.0000000000 0x00000308 -0.1999933334 19.9986666933 0.0000000000 0x00000308 -0.4499662510 29.9955002025 0.0000000000 An advanced format for structure PNT_DATA_2D_F64 shown below is similar to that for structure POS_DATA_2D_F64. Besides opt, x, y, and theta, the additional terms acc, dec, vi, vm, and ve provide information of acceleration, deceleration, start velocity, maximum velocity, and end velocity respectively for velocity planning. Example of file format for structure PNT_DATA_2D_F64 // opt x y theta acc dec vi vm ve 0x00000308 4381.000 139.000 0.000 2000.000 2000.000 0.000 200.000 0.000 0x00000308 4381.000 154.000 0.000 1405.169 1056.169 0.000 997.638 0.000 0x00000308 4553.000 240.000 0.000 6535.395 1535.395 0.000 653.540 0.000 0x00000308 1129.000 340.000 0.000 2352.663 3112.663 0.000 992.999 0.000 User should have basic understanding about how ADCNC library treat these imported points and data. Improper setting of these points will result in unexpected behavior easily. It is strongly recommended for user to test and run their own application by MCP2 first to avoid accident happening. MAPS-Embedded System Section 4

(2) Path optimize block: Only one input parameter tolerance error is needed for path optimization, and its unit is pulse. Figure 2(a) shows the results of path optimization: Instead of original trajectory automatically based on the ~ ~ , this block will find a new trajectory ~ is long enough to be tolerance error information. The length of new line capable to increase machining speed substantially. In figure 2(b), increasing tolerance error yields shorter time since point number decreases subcutaneously. If tolerance error is set zero, the path optimization block will find a default tolerance error by one-tenth minimum distance of this pattern and use it to generate new trajectory. One thing needed to know is the path optimization block will insert dwell points before and after rapid point to avoid distortion machining results. User has to take responsibility to choose tolerance error carefully to avoid issue of pattern distortion. (a) (b) Figure 2 Results of path optimization MAPS-Embedded System Section 5 00.20.40.60.811.21.41.602040Time (second)Tolerence Error (Pulse) 00.20.40.60.811.21.41.6020004000Point NumberTime (second)Point Number

(3) Velocity planning block In figure 3, the velocity planning block uses technique of connecting successive s-curve velocity profiles to reduce acceleration and deceleration time and improve machining efficiency. Unlike conventional trapezoidal velocity profile, the built-in cubic-order s-curve velocity profile guarantees to have continuous position, velocity, and acceleration during motion. The boundary velocity of velocity profiles is continuous and the start and end velocity of velocity profile are zero. Figure 3 Results of velocity planning A table shown below is to introduce the input parameters for velocity planning block. In order to have minimum motion time, velocity planning uses maximum acceleration/deceleration in ramping region and maximum velocity in cruise region to meet this requirement. The scenario of using max velocity/acceleration or rapid max velocity/acceleration for user depends on current motion itself is machining pieces or moving stage. One thing needs to know is start/end velocity keep zero when this point is set a rapid point. A velocity smooth factor is used to control jerk to reduce vibration when starting or breaking motor. The corner velocity limit is provided for user to adjust corner velocity. If this setting is zero, velocity planning will decrease corner velocity automatically. The input parameter cycle time is used for planning since the results of velocity planning must be integer times of it. If this setting is zero, a default value 1000 us will be used in this block. The cycle time parameter has to be equal to that used in motion control card. Table of input parameters for velocity planning Parameter Description Range Maximum Velocity Maximum velocity >0.0 Maximum Acceleration Maximum >0.0 for machining acceleration for machining MAPS-Embedded System Section 6 Unit Pulse per second Pulse per second squared

Rapid Maximum Maximum velocity >0.0 Velocity Rapid Maximum for moving Maximum Acceleration acceleration for >0.0 moving Pulse per second Pulse per second squared Smooth Velocity Factor Adjust smoothness of 0.0~1.0 Dimensionless velocity profile Corner Velocity Limit Limit corner velocity ; Suggested Dimensionless Cycle Time Motion control time ; if user sets 0, Nano second value is 8000000 the default cycle time 1000us is used. In order to get well-planned velocity profile for machining, the following will try to make user have more understanding about the insight methods and theory of velocity planning. MAPS-Embedded System Section 7

a. Corner velocity constraint In figure 4, in order to reduce effect of inertia, a corner deceleration mechanism is employed here, and the machining precision can be improved obviously. A description of calculating corner velocity is Where denotes maximum velocity of input parameter, is corner velocity limit of input parameter and is the angle between lines or arc. It is suggested the value of can be 8000000. This setting will make corner velocity be equal to about 1% maximum velocity when the angle of consequent lines or arc is larger than about 30 degree. If is set zero, the will be obtained automatically by velocity planning Where is maximum acceleration of input parameter and is the cycle time of input parameter. Figure 4 Corner velocity MAPS-Embedded System Section 8

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