Tech Today

WORDS BY DAVE MACKINNON

Continuing our deep dive into collision avoidance system brings us to a discussion of blind spot monitoring systems. Before we get into the nitty gritty, it’s worth noting that most consumers don’t know these systems are available as an add-on to their vehicle. As we move through the discussion of the technology, function and installation, think about how you can market these

profitable upgrades to your clients.

There are two classes of blind-spot monitoring solutions: camera-based and sensor-based. This article will discuss sensor-based solutions, and we’ll save the camera systems for the next issue.

Sensor-based blind spot systems typically use a pair of relatively short-range radar receivers mounted in the back

corners of a vehicle to monitor adjacent lanes for object motion. The sensors transmit a microwave-frequency radar signal, and then look for the reflections of those signals from nearby objects.

When driving on a road or freeway, the system creates a monitoring pattern that’s approximately one lane wide (12 feet) on either side of the vehicle with a coverage distance of 30 to 40 feet from the B-pillar. When the system detects an object entering or leaving these areas, it will illuminate the indicator that either you or your technicians have installed on or near the A-pillars. These indicators let the driver know that someone is traveling beside them and that they shouldn’t attempt to change lanes.

In a similar fashion to the parking sensors we talked about in the last issue, blind-spot warning systems provide an active warning to the driver if they activate the turn signal when there is a vehicle in the adjacent lane. In this scenario, the system will produce a clearly audible beep warning. Some solutions will flash the visual indicators to let the driver know not to change lanes or turn.

As a reminder, the benefit of an active warning solution is that the driver doesn’t need to remember to use it. There are no screens to look at. If there is danger of an accident, the system attracts the driver’s attention.

Historically, blind-spot warning systems had issues with false alarms. They might have falsely indicated there was a car in an adjacent lane when in reality, the vehicle was two lanes over. All of the solutions currently on the market are well into their second or third generation. As such, the radar field shape and sensitivity have been fine-tuned to provide reliable alerts.

Many of the current offerings integrate with the vehicle through the CAN data system to acquire turn signal and vehicle speed information. Likewise, these systems begin monitoring once the car is traveling above 15 miles per

hour to eliminate false warnings when parking or maneuvering.

Both factory-installed and aftermarket blind-spot monitoring systems are typically concealed behind the plastic bumper cover on the rear of a vehicle. Just like the signals from the police radar gun, the signals from these systems can travel through the plastic with little to no loss. However, this means that pickup trucks and vans with metal bumpers aren’t suitable applications for this type of solution.

VOXX Electronics offers a license plate frame-based blind-spot monitoring solution for vehicles with metal bumpers. The coverage field doesn’t extend as far up the sides of the truck or van, but the overall functionality remains the same. Depending on the application, this system can use CAN data or hard-wired connections from the turn signal and reverse lights. In the hard-wired installation, a GPS receiver integrated into the control module provides vehicle speed information. This information is used to activate the system once the vehicle is above 20 miles per hour. A dedicated reverse light connection switches the system to cross-traffic alert warning mode.

The detection area patterns that these systems monitor is fixed based on the position of the sensors. It’s essential to ensure the sensors are installed as per the manufacturer’s directions. There are minimum and maximum mounting height limits, and the angle the sensors face relative to the vehicle and the horizon needs to be correct. Many retailers will create templates on their shop floor using masking tape to ensure the systems are aligned correctly.

Once the sensors and indicators are mounted, and the system is wired into the vehicle, it’s worth taking the time to do a functionality test. Many solutions have a test mode that will activate the sensors while the vehicle is parked. You may also want to, with the permission of the vehicle owner, go for a drive around the block to make sure everything is

working flawlessly and the coverage is what the client expects.

Not every system on the market functions in the same way. Some only provide warnings if an adjacent vehicle is moving relative to your client’s vehicle. If someone pulls up beside the client’s car or truck, then holds that position, the indicators may turn off. Likewise, some systems don’t provide warnings if you are passing a vehicle slowly. If the car beside you is traveling only a few miles per hour slower, the indicators may not activate. Before offering a solution to your clients, make sure it will function the way they expect. Testing the system on a company vehicle may prevent a lot of headaches.

Many of the blind spot monitoring systems on the market include a Cross Traffic Alert mode. Cross-traffic alerts use the same radar technology, but with a wide and shallow beam pattern

that watches for vehicles or pedestrians approaching from the side as the driver backs out of a parking spot. Drivers backing into traffic on the road or in a parking lot have a notoriously difficult time seeing an approaching car or truck. Once the driver can see past an adjacent parked car or van, it’s likely that the rear of the vehicle is already six to eight feet into the active lane.

In cross-traffic alert mode, these systems provide both visual and audible warnings when they detect an approaching object. Just as with blind spot modes, they typically don’t produce false alarms from other parked vehicles, parking curbs, light posts or walls. The coverage pattern can extend as far as 90 feet on either side of the vehicle.

If you are interested in selling blind spot and cross-traffic alert systems to clients, demonstrating their capabilities and benefits is a great starting point. Set up one or two employee vehicles with systems so you can take prospective clients

for a drive around the neighborhood. Seeing the system in action is better than any image or video could ever be. During the drive, you can explain the intricacies of how the system functions relative to the movement of other vehicles on the road and discuss different indicator mounting location options.

You’ll want to update your website with content related to vehicle safety and collision avoidance solutions. Well-written articles that explain the benefits of these products will keep Google algorithms happy and bring people searching for that information to your store.

Finally, if you are serious about selling vehicle safety and collision avoidance solutions, sign up to be a Preferred Retailer on the Vision Zero Automotive Network website (www.vzan.org). Vision Zero and its partners aim to eliminate the 10,000 deaths that occur each year through the use of Advanced Driver Assistance Systems (ADAS) like backup cameras, parking sensors and blind-spot monitoring systems. There is no cost to join, so what are you waiting for?

Dave MacKinnon has worked in the mobile electronics industry since 1988 in almost every capacity, including roles as a Retail Salesperson, Installer, Sales Representative, Technical Trainer and Product Development Manager for some of the largest car audio companies in the world. Dave started his writing career in 2000 as the Technical Editor of a Toronto-based car audio magazine and has reviewed more than 450 products. Formally trained as an Electronics Technician, Dave is considered an industry expert when it comes to explaining how mobile audio components work, and he has crafted thousands of articles to share that knowledge. He’s currently the Head Writer for 1sixty8 media and the Editor-in-Chief at BestCarAudio.com.