Question

CNC system because only linear arc interpolation function? The numerical control system only has a linear arc interpolation function, so ______？

A. Only straight and circular contour parts can be processed;

B. Any contour parts can be machined directly;

C. After mathematical processing, any curved profile part can be machined.

What is CNC interpolation? What is linear circular interpolation? Can only machine straight and circular contour parts? Can any contour part be machined directly? After mathematical processing, can any curved contour parts be machined?

Answer 1

Because the CNC system only has the function of linear arc interpolation, it can only process the contour of the part.

So the answer is A.

Answer 2

CNC system (computer numerical control system) not only has linear interpolation and circular interpolation functions, its interpolation functions are richer and more complex. 

Specifically, the interpolation functions of CNC system mainly include but are not limited to the following:

1. Linear interpolation: Linear interpolation is the most basic interpolation method, which is used for interpolation operations of linear motion between two points. This interpolation method is simple and direct, and is suitable for linear processing scenarios.

2. Circular interpolation: Circular interpolation is used for interpolation operations on circular arc trajectories, which is suitable for circular arc processing, such as milling, turning, etc. The circular arc interpolation algorithm calculates the middle position of the tool during the processing process based on the radius, center and starting point coordinates of the arc.

3. Curve interpolation: Curve interpolation is used for interpolation operations on nonlinear trajectories, which is suitable for complex curve processing, such as three-dimensional surface processing. This interpolation method can generate smooth curve trajectories to meet the needs of high-precision processing.

4. Multi-axis interpolation: Multi-axis interpolation refers to the simultaneous interpolation operation on multiple coordinate axes. It is suitable for multi-axis linkage processing, such as five-axis machining centers. Multi-axis interpolation can realize one-time processing of complex parts and improve processing efficiency and precision.

5. Spline interpolation: Spline interpolation is a nonlinear interpolation algorithm that calculates the intermediate position of the tool during processing through a spline function. 

The spline interpolation algorithm can generate a smooth curve trajectory, which is particularly suitable for complex parts that require high-precision and high-quality processing.

In addition, the interpolation algorithm of the CNC system also includes different implementation methods such as point-by-point comparison interpolation, digital integral interpolation, and data sampling interpolation. 

These algorithms have their own characteristics and can be selected and optimized according to specific processing requirements and machine tool performance.

In summary, the interpolation function of the CNC system is far more than linear interpolation and circular interpolation. 

It also includes curve interpolation, multi-axis interpolation, spline interpolation and other methods to meet different processing scenarios and precision requirements.

Answer 3

CNC interpolation is an important technology in computer numerical control (CNC) systems, which involves the control strategy of CNC machine tools and the generation of motion trajectories. The following is a detailed explanation of CNC interpolation:

Definition of CNC interpolation

CNC interpolation refers to the calculation and control of the tool motion trajectory by computer according to the input part processing program to achieve a high-precision and high-efficiency processing process. 

The core task of the interpolation operation is to calculate the coordinate values ​​of several intermediate points between the starting point and the end point of the contour to approximate the ideal workpiece shape contour.

Principle of CNC interpolation

The interpolation principle is based on the interpolation method in mathematics, that is, between known data points, the value of unknown data points is calculated by a certain mathematical method. 

In the CNC system, the interpolation principle is applied to calculate the intermediate position of the tool during the processing process. 

The interpolation algorithm is a mathematical method to implement the interpolation principle. 

It calculates the intermediate position of the tool during the processing process based on the known starting and end point coordinates, as well as possible other parameters (such as the radius of the arc, the center of the circle, etc.).

Classification of CNC interpolation

CNC interpolation is mainly divided into the following categories:

1. Linear interpolation: interpolation operation of linear motion between two points, suitable for linear processing.

2. Circular interpolation: interpolation operation on circular trajectory, suitable for circular processing, such as milling, turning, etc.

3. Curve interpolation: interpolation operation on nonlinear trajectory, suitable for complex curve processing, such as three-dimensional surface processing. Common curve interpolation algorithms include spline interpolation, NURBS curve interpolation, etc.

4. Multi-axis interpolation: interpolation operation on multiple coordinate axes at the same time, suitable for multi-axis linkage processing, such as five-axis machining center, etc.

CNC interpolation algorithm

Common CNC interpolation algorithms include pulse incremental interpolation and digital incremental interpolation (data sampling interpolation):

1. Pulse incremental interpolation:

- The interpolation result is output in the form of pulses, and each pulse represents a certain displacement.

- Applicable to open-loop CNC systems with stepper motors as actuators.

- Common pulse incremental interpolation algorithms include point-by-point comparison method and digital integration method (DDA).

2. Digital incremental interpolation (data sampling interpolation):

- The time for processing a section of curve is divided into several equal interpolation cycles, and an interpolation operation is performed after each interpolation cycle.

- Applicable to closed-loop and semi-closed-loop position sampling control systems with DC or AC motors as actuators.

- The interpolation calculation is divided into two steps: coarse interpolation and fine interpolation. Coarse interpolation calculates the movement increment of each coordinate axis within the interpolation cycle, and fine interpolation is adjusted according to the error between the actual position and the command position.

Application of CNC interpolation

CNC interpolation is widely used in manufacturing equipment such as CNC machine tools, CNC machining centers, and 3D printers. 

Through CNC interpolation technology, these devices can perform high-precision processing and manufacturing according to predetermined trajectories and speeds.

Precautions for CNC interpolation

1. Selection of interpolation algorithm: The appropriate interpolation algorithm should be selected based on factors such as processing accuracy, processing efficiency, and equipment performance.

2. Control of interpolation accuracy: interpolation accuracy directly affects processing accuracy, so it is necessary to ensure interpolation accuracy by optimizing algorithms and improving equipment accuracy.

3. Control of processing speed: interpolation speed should match the feed speed of the machine tool to avoid processing errors or machine vibration caused by excessive speed.

In summary, CNC interpolation is one of the key technologies for CNC machine tools to achieve high-precision and high-efficiency processing.

By continuously developing and optimizing interpolation algorithms and technologies, the processing performance and manufacturing level of CNC machine tools can be further improved.