PFM Photoelectric Sensor Calibration for Drawer Object Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Photoelectric sensors struggle to accurately detect the presence, absence, proximity, or distance of objects with different types, dimensions, and reflectivity, leading to inconsistent performance.
Innovation Solution
A photoelectric sensor driven by pulse-frequency modulation (PFM) with adjustable frequency to control the average intensity of pulsed light, calibrated for the type of object and effective range, using a light transmitter and photoelectric receiver with processing circuitry to output a PFM signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the photoelectric sensor uses fixed intensity light emission, then the device complexity is reduced, but the detection precision varies for different object types and distances
Solution Approach 1:
The patent applies dynamics by making the light emission intensity variable rather than fixed. The controller adjusts the intensity of light pulses emitted by the transmitter based on detection requirements for different object types and distances, allowing the sensor to adapt to varying measurement conditions and improve detection accuracy across diverse scenarios
Solution Approach 2:
The patent changes the parameter of light intensity from a constant value to a variable parameter. By modifying the intensity of emitted light pulses according to the specific detection task and object characteristics, the system optimizes the signal strength received from different objects, thereby improving measurement precision without requiring complex additional hardware
2Length of stationary object
If the photoelectric sensor increases light intensity for distant objects, then the effective range is extended, but the energy consumption increases
Solution Approach 1:
The system dynamically adjusts light emission intensity based on the required detection range and object distance. When detecting distant objects, the controller increases light intensity to extend the effective range, while for nearby objects it reduces intensity to conserve energy, optimizing the balance between range and energy consumption in real-time
Solution Approach 2:
The patent employs periodic pulsed light emission rather than continuous emission. The controller emits light in controlled pulses at specific intervals, allowing the system to achieve the necessary detection range during pulse periods while consuming minimal energy during idle periods, thus extending effective range without proportionally increasing overall energy consumption
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
Enhances the sensor's ability to accurately detect the presence of objects by adjusting the frequency and intensity of pulsed light based on object type and range, improving detection accuracy.
Implementation Method 1
a photoelectric receiver configured to receive a reflection of the pulsed light off of the object in proximity of the photoelectric sensor, and convert the reflection of the pulsed light to an electrical signal
Data Source
AI summary
A tool storage system is provided that includes a drawer, and an optical system configured to detect presence of an object in the drawer. The optical system includes a photoelectric sensor and processing circuitry. The photoelectric sensor includes a light transmitter configured to emit pulsed light, and a photoelectric receiver configured to convert a reflection of the pulsed light off of the object to an electrical signal that indicates proximity of the object and thereby the presence of the object in the drawer. The processing circuitry is configured to output a pulse-frequency modulation (PFM) signal from which the light transmitter is driven to emit the pulsed light. The PFM signal has a frequency that is adjustable to control an average intensity of the pulsed light, the frequency calibrated for a type of the object and an effective range of the photoelectric sensor.