Linear Stage Error Measurement Using Moving Optical Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current error measurement techniques for linear stages, such as laser interferometers and triangulation-based laser rangefinders, are costly and limited in measurement range, with decreasing precision at longer distances, making them unsuitable for accurate long-traveling motion error measurement.
Innovation Solution
An error measurement method and device using an optical measurement assembly with a light source, optical lens, and photoelectric sensor disposed on a linear stage, where the light beam is adjusted to maintain illumination on a sensing area through relative motion of the light source, optical lens, or photoelectric sensor, allowing continuous error measurement beyond the sensor's range with minimal construction cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If triangulation-based laser rangefinder is used for error measurement, then measurement range is limited by sensor size, but measurement resolution and precision deteriorate when measurement distance increases
Solution Approach 1:
The patent makes the optical measurement assembly movable by mounting it on the moving stage of the linear stage. This dynamic configuration allows the assembly to travel with the stage, maintaining a constant, optimal measurement distance while enabling measurement over the entire long-traveling range of the linear stage, thus resolving the contradiction between extended measurement range and maintained precision
Solution Approach 2:
The patent introduces the moving stage as an intermediary carrier that transports the optical measurement assembly along with it. This intermediary solution allows the measurement system to access long-traveling distances without increasing the measurement distance from the sensor to the target, thereby maintaining measurement resolution while extending the effective measurement range
2Measurement precision
If laser interferometer or multi-axis calibrator is used for error measurement, then measurement precision is improved, but construction cost increases
Solution Approach 1:
The patent makes the optical measurement assembly multi-functional by mounting it on the moving stage, allowing it to simultaneously serve as both a measurement device and a traveling component. This eliminates the need for separate, expensive measurement systems like laser interferometers, achieving high-precision error measurement at lower cost through the dual functionality of the assembly
Solution Approach 2:
The moving stage serves itself by carrying the optical measurement assembly, enabling the stage to perform both its primary motion function and the secondary function of positioning the measurement device. This self-service approach eliminates the need for additional expensive measurement equipment, reducing construction cost while maintaining measurement precision
3Stability of the object's composition
If light source, optical lens, and photoelectric sensor are fixed on stationary platform, then optical path stability is improved, but measurement range is limited by sensor size
Solution Approach 1:
The patent transforms the static optical measurement system into a dynamic one by mounting the assembly on the moving stage. The assembly moves dynamically with the stage while maintaining internal optical stability, enabling measurement over the entire travel range of the linear stage without being constrained by the stationary sensor size
Solution Approach 2:
The patent adds the dimension of motion along the linear stage's travel direction to the optical measurement system. By mounting the assembly on the moving stage, the system gains the ability to measure errors across the full travel range of the stage, transforming the measurement capability from a fixed-point measurement to a multi-position measurement along the travel dimension
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate error measurement for long-traveling motions with reduced construction costs by preventing light beam deflection and extending the measurement range, ensuring precise geometric error assessment in machine tools.
Implementation Method 1
The first optical path is formed by emitting a light beam with the light source and transmitting the light beam to a sensing area on the photoelectric sensor through the optical lens
Implementation Method 2
a photoelectric sensor... transmitting the light beam to a sensing area on the photoelectric sensor
Data Source
AI summary
An error measurement device and an error measurement method are provided. The optical measurement assembly of the error measurement device includes a light source, an optical lens, and a photoelectric sensor. The light beam emitted by the light source is transmitted to a sensing area on the photoelectric sensor to form a first optical path illuminating on a first light-spot position of the sensing area. The moving stage is moved by a linear displacement, so that the light beam is transmitted to the photoelectric sensor to form a second optical path illuminating on a second light-spot position of the sensing area. The processor calculates a movement error of the moving stage and controls the actuator to drive one or more of the light source, the optical lens, and the photoelectric sensor to perform a relative motion, so that the light beam illuminates on the first light-spot position again.