Angled Laser Sensor for Reflective Metal Strip Distance Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional distance measurement technologies, such as laser rangefinders, fail to accurately measure the distance to surfaces with fluctuating reflectivity, particularly in metal coating processes where the surface can be both reflective and non-reflective, leading to inconsistent coating thickness and equipment damage due to the inability to handle both conditions simultaneously.
Innovation Solution
A measuring apparatus comprising a measuring light source and sensor unit positioned at an angle to a diffuse target surface, along with a reference light source and sensor unit, utilizing laser or LED light sources and a processor unit to classify readings as direct or reflected, allowing for real-time distance calculation regardless of surface reflectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional laser rangefinders are used to measure distance to metal surfaces, then measurement can be performed on non-reflective surfaces, but measurement fails on reflective surfaces due to direct reflection without light dispersion
Solution Approach 1:
A diffuse reflective target is introduced as an intermediary element between the laser sensor and the metal strip. The target reflects laser light diffusely regardless of the strip's surface reflectivity, providing a consistent measurement reference. This mediator enables reliable distance measurement whether the strip surface is reflective or non-reflective.
Solution Approach 2:
The measurement system is designed to handle multiple surface conditions (reflective and non-reflective) using a single unified approach. By positioning the laser at an angle and using a diffuse target, the system achieves universal measurement capability across varying strip surface conditions without requiring different measurement modes.
2Manufacturing precision
If the air knife is positioned close to the strip for better coating control, then coating consistency improves, but the strip may hit the air knife causing shutdowns and damage
Solution Approach 1:
The laser measurement system continuously monitors the distance between the air knife and strip surface in advance, allowing the control system to predict potential collisions before they occur. This preliminary detection enables proactive adjustment of air knife positioning or strip speed to prevent shutdowns while maintaining optimal coating control.
Solution Approach 2:
Real-time distance measurement data is fed back to the control system, which adjusts operating parameters to maintain safe clearance between the air knife and strip. This closed-loop feedback ensures both coating precision and equipment reliability by dynamically balancing close positioning with collision prevention.
3Adaptability or versatility
If ultrasonic sensors are used to measure distance to hot surfaces, then measurement can be performed, but the sensors fail on very hot surfaces
Solution Approach 1:
The patent replaces ultrasonic (acoustic) measurement with optical laser measurement. Laser light is not affected by high temperatures in the way sound waves are, allowing accurate distance measurement to hot metal strips without sensor failure. This substitution of measurement physics enables operation across the full temperature range encountered in coating processes.
4Reliability
If induction sensors are used for distance measurement, then measurement can be performed, but the sensors have limited range and do not cover full operating conditions
Solution Approach 1:
The laser measurement system provides universal distance measurement capability across the entire operational range of the air knife, from closest to farthest positions. Unlike induction sensors with limited range, the laser system maintains accuracy throughout the full stroke, covering all operating conditions without requiring multiple sensor types.
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, real-time measurement of distance between air knives and coated metal strips during coating processes, improving coating consistency and reducing equipment downtime by accounting for both reflective and non-reflective surfaces, thus enhancing process control and reducing financial losses.
Implementation Method 1
a measuring light source and sensor unit positioned at an angle to the perpendicular of the surface to allow the light to be reflected to a diffuse target surface in a known position
Implementation Method 2
The laser diode emits light pulses of about 35-45 nanoseconds, which hit the target and a small amount reflects off the target through diffuse scatter
Data Source
Figure 1
Figure 2a~2b
Figure 3
AI summary
A measuring apparatus (10), for measuring the distance to a surface (14) having fluctuating reflectivity, the measuring apparatus (10) comprising, a measuring light source and sensor unit (16) positioned at an angle to the perpendicular of the surface (16) to allow the light to be reflected to a diffuse target surface in a known position; and a processor unit, wherein the processor unit is adapted to collect and analyse data from the a measuring light source and sensor unit (16) and classify whether the reading of the measuring light source and sensor unit (16) is a direct reading or a reflected reading.