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CityMax Pro

Urban Perimeter Lighting Reimagined.

10 Days

Final Year BSc Live Brief

Lighting Design

Machine Vision

Serviceability

Designed for Holophane + the LIA

D&T Education in the UK faces a triple-threat: a dire shortage of specialist teachers, ageing equipment, and significant budget cuts.

As a result, lots of students come up with ideas for their GCSE/A-Level major projects that involve electromechanical systems but do not know how to build them.

CityMax is a trademark of Holophane Europe Ltd. The name CityMax Pro was chosen to represent an technological augmentation and industrial redesign of a product Holophane currently offers.

Co-exist?

Co-thrive.

A Mission to Make Peace with the Natural World

An abundance of bright, cool-temperature light spills from the fringes of urban areas to the natural spaces that wildlife call home. Hedgehogs Erinaceus europaeus, hares Lepus capensis, and rabbits Oryctolagus cuniculus are among species that freeze or crouch under cool-lit areas, increasing the risk of being hit by a pedestrian or a vehicle. [1] A large number of sources conclude that the use of warmer/amber-toned artificial lighting has a reduced impact on wildlife.

What does CityMax Pro do?

CityMax Pro emits a low-intensity, warm beam of ~2700K. Six IR vision sensors give it a 360-degree view and the ability to detect pedestrians and vehicles in its field.

When a pedestrian is detected, CityMax Pro can selectively illuminate the area around and in front of the pedestrian. This provides useful illumination to the pedestrian without causing disturbance to wildlife.

To further minimise disruption to wildlife, the beam can be entirely switched off for areas that are inhabited by animals: woodlands, bushes, grass fields, hedges, etc.

Optical Design

A Sectional View into the Luminaire

1

An LED shines directly into the first glass element.

It has a wide angle beam which presents challenges when trying to control the direction of the beam for the selective beam feature of CityMax Pro.

2

Each beam is 'straightened' by the first glass element.

A specially formed lens known as a collimator aligns the beam of the LED, ensuring the output rays are parallel. The wide beam from each LED would be hard to selectively control as it would mix and interfere with beams from other LEDs; this is solved by the collimator.

3

All of the beams shine into a second glass element.

Another lens receives the individual, aligned beams and spreads the resultant aggregate beam over a wide area. This ensures the luminaire field of illumination is not limited by the beam alignment process from the collimator lens. This second lens type is called a difuser lens.

4

103 LEDs and a 2-stage optic array enable a highly-accurate selective beam.

CityMax Pro ensures tight control over the intensity and temperature of localised areas of a luminaire's light beam by using 103 Samsung CSP LEDs arranged in a icosahedral projection for even coverage.

The combination of the prismatic collimator and the diffuser lenses solve the problem of the two opposing requirements of the luminaire: selective control with minimum inter-beam interference and a wide coverage area.

4

103 LEDs and a 2-stage optic array enable a highly-accurate selective beam.

CityMax Pro ensures tight control over the intensity and temperature of localised areas of a luminaire's light beam by using 103 Samsung CSP LEDs arranged in a icosahedral projection for even coverage.

The combination of the prismatic collimator and the diffuser lenses solve the problem of the two opposing requirements of the luminaire: selective control with minimum inter-beam interference and a wide coverage area.

Optical Design

A Sectional View into the Luminaire

1

An LED shines directly into the first glass element.

It has a wide angle beam which presents challenges when trying to control the direction of the beam for the selective beam feature of CityMax Pro.

2

Each beam is 'straightened' by the first glass element.

A specially formed lens known as a collimator aligns the beam of the LED, ensuring the output rays are parallel. The wide beam from each LED would be hard to selectively control as it would mix and interfere with beams from other LEDs; this is solved by the collimator.

3

All of the beams shine into a second glass element.

Another lens receives the individual, aligned beams and spreads the resultant aggregate beam over a wide area. This ensures the luminaire field of illumination is not limited by the beam alignment process from the collimator lens. This second lens type is called a difuser lens.

4

103 LEDs and a 2-stage optic array enable a highly-accurate selective beam.

CityMax Pro ensures tight control over the intensity and temperature of localised areas of a luminaire's light beam by using 103 Samsung CSP LEDs arranged in a icosahedral projection for even coverage.

The combination of the prismatic collimator and the diffuser lenses solve the problem of the two opposing requirements of the luminaire: selective control with minimum inter-beam interference and a wide coverage area.

it is important to get the

right light

at the

right place

and for it to be used at the

right time

Aligned with UK Government Initiatives

CityMax Pro is designed to align with domestic and global government environmental initiatives. These are aimed at reducing the issue of light pollution and derivative problems, such as energy consumption and wildlife impact. CityMax Pro's selective beam technology provides a solution to these challenges.

Client-Driven

Designed to Leverage Holophane's Unique Strengths

My research and conversations with members of the Holophane team informed me of their unique strengths. They are known for their unparalleled capability in manufacturing bespoke glass prismatic lenses.

In the optical design ideation stage of this project, I leaned into this strength and tried to find ways to exploit it best.

CityMax Pro leverages Holophane's distinct expertise in prismatic lenses by using a prismatic collimator. The aligning properties of a collimator could only effectively be applied to each of the 103 LEDs with a prismatic design - a perfect utilisation of the client's advantage.

See the Prismatic Collimator in 3D

Move your mouse over the collimator lens.

Grounded in Reality

Behind the Scenes: Research

There exists a patent for the application of prismatic collimator designs in lighting fixtures (see US Patent No. US9632326B2), however it appears to have expired as of 2023. As such, it seems to be a viable design.

A patent held by Koito Manufacturing Co Ltd (shown below) for the invention of a selective-beam headlight for an automobile. This design features a
selective high beam and a dipped beam which come out of the same diffuser lens. Designs like this served as an inspiration for the optics
design of CityMax Pro.

Enabled by the Latest Technology

Six-Sensor IR Vision Array

CityMax Pro uses six Sony infrared (IR) camera sensors to capture a full 360-degree field of view around the luminaire. These visual feeds are processed by the Intel® Movidius™ Myriad™ X Vision Processing Unit (VPU). The VPU runs an inference model to distill the vast amount of visual information into simpler data: the location and direction of each pedestrian, cyclist, etc. in its FoV.

This is passed to the low-power coprocessor which is responsible for controlling the LED matrix, selectively adjusting each LED's brightness and colour temperature to generate the output needed.

Using a dedicated VPU and low-power coprocessor means the computation tasks are carried out with optimal power efficiency as each stage of the computation pipeline is run on purpose-designed circuits. This helps keep CityMax Pro's power consumption as low as possible. Whereas cloud-processed urban infrastructure vision sensors could be abused for surveillance, CityMax Pro's on-device processing provides privacy assurances to pedestrians.

Sony IMX219 IR Vision Sensor

Low Power Co-Processor

Intel® Movidius™ Myriad™ X VPU

Seeing Clearly

Behind the Scenes: Optics Research

Using lens simulation software, I tested out several ideas for the optic array. These were first sketched on post-it notes with only somewhat feasible designs being prototyped in software.

CityMax Pro's internal electronics sub-assembly

Leaving...

CityMax Pro

Coffee Machine

The Ultimate Endorsement of Technology in Coffee Making

On to...

5 Weeks

Final Year BSc Electronics Demo

Face Recognition

Systems + Circuit Design

Serviceability

A Technical Challenge from our University Tutors

This project was set as a challenge for us to demonstrate the best of our ability without regard to the traditional constraints of a design project: cost, business feasibility, utility, etc.

The goal was to make the most advanced coffee machine we could using as many forward-looking technologies as possible. It also needed to fit around and use an unmodified AeroPress coffee press.

See Project in Portfolio Archive

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