Radar is an important CAS sensory component in a car's inventory of technologies used to pinpoint various objects on the road it wants to avoid.

Collision Avoidance Systems (CAS): CAS is a group of advanced technologies engineered into cars to warn and/or aid drivers to prevent collisions. These technologies are part of a rapid shift toward autonomous vehicles on the road. CAS technologies include tangible elements like warning sounds, vibrating seats, side mirror and/or dashboard signals. All of these features are designed to alert drivers to mitigate potential collisions with objects on the road. However, for these advanced technologies to be effective, the CAS system in the vehicle needs to be able to "see" the object.

Why is Radar so important? Radar is a proven, reliable, and low cost technology used to calculate the distance to objects; allowing the car to pinpoint where an object is located on the road. Radar is also a preferred sensory component because it works low visibility or poor conditions.



Radar is transmitted in waves.

Radar waves travel at the speed of light.

When Radar waves are reflected back by an object, the time is measured from when the radar wave was originally transmitted allowing distance to be calculated.

Knowing the distance to an object (Distance =Time X Speed), radar can pinpoint the location of that object.

Radar reflection is measured in - Radar Cross Section (RCS) Values.

RCS values are impacted by: size, shape, material and angles.

Large, flat, metallic objects (like vehicles) have very HIGH - RCS values.

Smaller, less dense, organically shaped objects (like a person riding a bicycle, motorcycle or running) have LOWER - RCS values.

Our team went through several phases of development, design and testing. Beginning with the end in mind, we identified the key elements that were critical for the technology to be relevant and useable by cyclists. Ultimately this lead to our decision to initially engineer the technology into a commonly used safety device like a rear tail light.





First, we established our project objectives and desired outcomes.





Primary Project Objective: Develop a radar-based application easily integrated into commonly used cycling products for mounting on the rear of a bicycle.





Desired Outcomes: Increase the visibility of a cyclist to a CAS equipped vehicle at a greater range to help avoid potential collisions between the two.







The design elements of focus we believed most critical to meeting the project objectives and desired outcomes are as follows:





1) Performance – The technology design must increase the detection range of a cyclist by a CAS equipped vehicle in an effort to provide a car and/or driver more time to avoid a potential collision.





2) Form (Size & Shape) – The form of the technology needed to be compact in order for it to easily be integrated into a commonly used cycling product and/or for it to be engineered into a stand-alone device that could be easily mounted on the rear of a bicycle.







3) Lightweight – The weight of a device that a cyclist mounts on his/her bicycle is always a consideration. Our design targets were to NOT add more than 20-25g to any existing product integration and/or produce a stand-alone device that weighed 55g or less.





4) Low Cost – The technology application, regardless of how effective, had to be affordable. Our design target was an initial product that could be purchased by a broad range of consumers regardless of the cost of their bicycle.







We aggressively started the research and design of our technology idea in August of 2014. This included developing specific relationships with experts in the radar industry to better understand the limitations and uses of this technology. We also initiated a dialogue with specific Tier 1 suppliers of CAS forward-looking radar systems to the automotive industry. One of the most important discoveries during initial development was the techniques used to increase the RCS value of a cyclist, which is the measured visibility by radar, as a means to increase the distance a cyclist becomes visible to the CAS forward-looking radar sensory system in a car.





The science of radar reflection to increase or decrease the RCS value of an object making it more or less visible to radar is not new. The application of this technique maybe most familiar to those who have heard the term "stealth". Stealth techniques use radar reflection to make an object less visible and/or "invisible" to a radar system. We have reverse engineered this technique into a product used by a cyclist to make them more visible to a car equipped with radar. This is a revolutionary application of radar technology.





Increasing RCS & Benefits:

Our primary target was to increase the RCS value of a cyclist to a level that the distance range visible to a CAS forward-looking radar was increased 100%. The guidelines used to establish our visibility range targets for testing are published by the Federal Motor Safety Standard.







Speed vs Distance Table:

How “detectable” an object is by radar is based on an objects reflective strength. Reflective strength is most commonly measured in decibels (dB) and assigned a "value" defined as the objects - Radar Cross Section (RCS). When referencing the dB measurement of an object, what is really being described is the logarithmic comparison of the signal of that object from the time of transmission to receipt (or reflection back) to the original transmission.





Decibel Measurement System:

Below in Figures 5 & 6 is a image of the RCS values measured in dB assigned to "familiar" objects and an image of a CAS forward-looking radar sensory system during testing in an anechoic radar chamber.





Our initial prototype designs originated using the mathematical analysis of four passive solutions. We plotted responses associated with each design and measured these responses against various angles and orientations. Several reflection renderings were created and computer modeling was used to evaluate our initial predictions as well as forecast results.





We narrowed our focus on form and size. Bikes come in a range of sizes and models. Many enthusiasts already crowd their bars, bicycle frames and even person with accessories like cycling computers, saddle bags, front/rear racks, bells, front/rear lights, fenders, clip-on devices and more. Our goal was to engineer OTR Technology into a package small enough to satisfy the needs of a cyclist, but remain compatible with the 76-GHz frequency of a CAS forward-looking radar sensor.

We created several units to test our reflection models and measure the impact form and size had on the increase and/or decrease of an object's RCS value. Testing was first conducted in an anechoic chamber at a Tier 1 CAS forward-looking radar supplier to the auto industry. Early testing was very successful and the data received exceeded our pre-test computer modeling and targets we set as performance standards. Figure 8 graphically displays the vertical pattern results of several geometrical shapes & sizes used in testing.

Figure 9 is a photo taken at the radar range. It is an image of some of the early designs tested that are clearly too large to mount on a bicycle or be used as a stand-alone device. While the initial designs may appear very simple to the casual observer, they are actually highly engineered to amplify the RCS value of an object. The most important early success we achieved was the accuracy of our return signal.

Radar Range Test Results Summary: During the first phase of testing a major breakthrough was our ability to amplify a return a signal back to the point of origin that increased an objects RCS value well beyond our performance minimum (+5dB) even if the original signal was received at askew.

Having determined the specific shape and size needed to achieve our performance targets, we shifted our focus to the actual integration of OTR Technology into a product. As part of the final phase of development we wanted to test our construction of OTR Technology in relevant cycling products. Equally important at this point was the total weight and materials we used. Weight and materials ultimately impact the cost and commercial viability of delivery of a product to the consumer (you).

Relatively speaking, bikes are not heavy objects and one of our key project targets from the beginning was a product that could be mounted on the rear of any bicycle across a range of sizes and styles. Materials we selected for initial prototypes included molded plastic, aluminum and carbon fiber. Prototypes were produced in key sizes using a range of materials to conduct additional field testing and measure the results achieved against results in the anechoic radar chamber.

Field Testing: Testing included using a CAS forward-looking radar system purchased from a Tier 1 supplier to the auto industry. The CAS forward-looking radar system was mounted on a tripod at the height radar sensors are commonly located in vehicles. We were able to measure the RCS values of a cyclist with and without an iLumaware prototype in a dynamic environment. We were able to analyze the performance data of each size in real-time and test a full-range of riding conditions commonly encountered by cyclists on the road.

Field Testing Examples:

Test 1.1B - A cyclist on open road in light traffic WITH a prototype and minimum road furniture and/or additional objects. Test Size B, the cyclist visibility range exceed 150-meters.

With OTR:



