Surveillance Camera Tilt Control Using Acceleration Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Surveillance cameras using open loop control methods struggle to instantly detect and correct variations in tilt-angle due to gravity, vibrations, wind, and heat over time, leading to gaps in surveillance, and require expensive location detecting devices like encoders when using closed loop control.

Innovation Solution

Employing an open loop control method that utilizes acceleration values from an acceleration sensor to monitor and maintain the tilt-angle, combined with a gyro sensor and photo-interrupt sensor, allowing real-time detection and correction of tilt-angle variations without the need for additional expensive equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If closed loop control method is used with encoder to detect and correct tilt-angle variations, then tilt-angle accuracy is improved, but manufacturing cost increases due to expensive location detecting devices

Engineering Contradiction:
Improvetilt-angle accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive encoders with inexpensive acceleration sensors and gyro sensors that can be integrated into the camera body. These sensors provide sufficient tilt-angle detection capability without requiring precision mechanical encoders, thereby reducing manufacturing costs while maintaining adequate measurement precision for surveillance applications

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent substitutes mechanical encoder-based detection with sensor-based detection using acceleration sensors and gyro sensors. This electronic sensing approach eliminates the need for mechanical encoders and their associated complex feedback mechanisms, reducing both cost and device complexity while achieving the required tilt-angle monitoring functionality

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If open loop control method is used to reduce device complexity and cost, then manufacturing cost is reduced, but tilt-angle accuracy deteriorates as the camera cannot instantly detect and correct variations due to gravity, vibrations, wind, heat

Engineering Contradiction:
Improvecontrol system complexityVSAvoidtilt-angle accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces feedback through acceleration sensors and gyro sensors that continuously monitor tilt-angle variations. Although the control remains open loop, the sensors provide real-time tilt-angle information that enables the system to detect and respond to variations caused by gravity, vibrations, wind, and heat, thereby maintaining tilt-angle accuracy without requiring complex closed-loop control

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent utilizes acceleration sensors and gyro sensors that serve multiple functions: they detect tilt-angle variations, provide feedback for correction, and can operate in various environmental conditions. This multi-functionality allows the system to maintain tilt-angle accuracy across different scenarios without requiring separate specialized components for each function

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If open loop control method is used with stepping motor, then device complexity is reduced, but reliability deteriorates as surveillance gaps occur when tilt-angle variations are not corrected in real-time

Engineering Contradiction:
Improvecontrol system complexityVSAvoidsurveillance continuity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements feedback using acceleration sensors and gyro sensors that continuously monitor tilt-angle variations. This feedback mechanism ensures that tilt-angle changes are detected in real-time, allowing the system to maintain reliable and continuous surveillance by promptly identifying and responding to variations that could otherwise create surveillance gaps

Inventive Principle:
Principle #23Feedback

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 real-time detection and correction of tilt-angle variations, maintaining accurate surveillance while being economically efficient by utilizing existing sensors, reducing manufacturing costs and ensuring continuous monitoring.

Implementation Method 1

the tilt-angle after finishing the tilting may be monitored and maintained by using acceleration values in at least one axis of the acceleration sensor

Methodology Applied
Scientific EffectAcceleration sensor measurement: Accelerometer

Implementation Method 2

most of surveillance cameras include a gyro sensor for detecting and correcting shaking of the camera during imaging

Methodology Applied
Scientific EffectGyroscopic effect: Gyroscope

Implementation Method 3

the tilting operation to the command tilt-angle may be normally performed by using the photo-interrupt sensor that is inexpensive

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP3496063B1Method of maintaining tilt angle, method of controlling tilting, and surveillance camera
Publication Date: 2021.07.21 HANWHA VISION CO LTD
  • EP3496063B1 patent drawingFigure 1
  • EP3496063B1 patent drawingFigure 2
  • EP3496063B1 patent drawingFigure 3~4

AI summary

A method of rotating a surveillance camera (101) having an acceleration sensor (31) and being controllable by a processor (207) to maintain a tilt-angle to conform to a command tilt-angle, includes the steps of moving the surveillance camera (101) tilt to a predetermined command tilt-angle in response to a signal from the processor (207); time-periodically calculating estimated tilt-angles by using acceleration values in at least one axis of an acceleration sensor (31); calculating a difference value between an estimated tilt-angle of a current time period and an estimated tilt-angle of a previous time period; and when the difference value between the estimated tilt-angles exceeds a set limit, moving the surveillance camera (101) to another position to correct the tilt angle according to the difference calculate.