ProjectsHalo
Halo
Halo is a two-part cycling safety system for road cyclists in Hong Kong. It senses vehicles approaching from behind and tells the rider where they are, without the rider turning their head or taking a hand off the handlebars.
- Type
- Portfolio project, outside school
- Stage
- A resolved concept, with full CAD, renders and a physical prototype
- Software
- Autodesk Fusion
Where the idea came from
When my friends and I rented bikes on a summer holiday in Niseko, I noticed how dangerous cycling felt, even in the suburbs and the countryside. In Hong Kong it is even more so.
Who it is for
Road cyclists in Hong Kong, and particularly less experienced riders, for whom checking over the shoulder is still a conscious effort and not yet an automatic one.
The two parts
Halo Rear
Sits on the back of the helmet. It contains the radar, a motion sensor, the battery and two small vibrating units.
Halo Cue
A slim tapered module that clips to the lower edge of the helmet and angles forward, so that its tip rests on the cheekbone just in front of the ear. It delivers sound through the bone, which leaves the ear completely open to traffic noise. A thin cable along the helmet strap joins the two parts.
How it tells the rider
The alerts are split across two senses. Vibration tells the rider which side the vehicle is on. A tone tells them how urgent it is, rising in pitch and speed as the vehicle gets closer.
There is no speech, because words take up the attention a rider needs for decisions in traffic. Distant vehicles produce vibration only, with no sound, which stops the system from becoming annoying enough to switch off.
Correcting for head turns
Because the sensor sits on the rider's head and not on the bike, it swings whenever the rider looks over their shoulder. Without correction, a car directly behind would be reported as being off to one side.
The motion sensor measures how far the head has turned and corrects for it, so the alert always refers to the road and not to where the rider happens to be looking.
Research
Hong Kong accident statistics, published research on night-time visibility, a questionnaire, and an interview with a semi-professional racing cyclist.
What changed along the way
- MountingHalo Cue first clipped to the point where the helmet straps cross. That point moves whenever the straps are adjusted, and the tip needs steady pressure against the face, so the clip moved to the rigid helmet shell.
- FormIt started as a hexagonal puck with a rotating ring. It became a tapered blade with the controls near the mount, which keeps weight away from the end that has to stay in contact with the face.
- Position of the sound unitIt was first drawn over the ear, which would have blocked the ear and defeated the reason for using bone conduction. It moved forward onto the cheekbone.
- ControlsThe rotating ring was replaced with two buttons that differ in shape, size, height, texture and stiffness, so they can be told apart by touch alone while wearing gloves.
What I made
A CAD model in Autodesk Fusion, renders, a physical prototype, and cardboard mock-ups of two alternative sensor positions. Halo was developed to prove the idea and will remain a concept.
To add: what the prototype is made of and how it was made (3D printed or not, material, finishing, bought-in parts).
What comes next
Two alternative positions for the rear sensor, both mocked up in cardboard: a pod clamped to the seatpost, and a pod on a strap around the lower back.