How to Choose the Right Sensor for All-Weather, Outdoor Applications

Robots require robust navigational hardware or sensors to operate in complex outdoor environments such as mines, farms, and ports. This hardware should help outdoor robots deal with problems like unpleasant weather, bright sunlight, and extreme temperatures that can impair the overall reliability of the robot and affect operations adversely.

Choosing the right laser sensors (LiDAR) means that your outdoor robot’s navigation systems run accurately and mission-critical operations are performed flawlessly. In addition, these sensors will ensure that the robot gets through adverse conditions without sustaining damage or causing any sort of disruption to ongoing processes.

Here, we have laid down the top five critical factors you should consider while choosing a LiDAR sensor for your outdoor robot design.

Environmental rating

A high environmental rating is crucial to consider while choosing LiDAR for outdoor robots. If a laser scanner is not resilient enough to sustain in conditions that outdoor robots are exposed to, the sensor may experience early failure or malfunction. At the same time, a laser scanner with a robust design and high enclosure rating will reduce the mean time between failures and assure the longevity of the navigational system. For instance, an IP67 electrical enclosure rating signifies that the device is protected from the harmful effects of water and dust. All Hokuyo LiDAR sensors are either IP64 or IP67-approved, making them reliable sensing solutions for outdoor use.

Ambient light resistance

Ambient light is one of the significant challenges that robots face while operating outdoors. LiDAR employs time-of-flight technology to detect objects within the sensor’s proximity. The laser scanner releases a pulse of light which comes in contact with the object and reflects back. The amount of time the pulse takes to travel from the sensor to the reflector and back determines the distance. This is how the robot estimates the position of nearby objects and avoids obstacles or collusion.

Extreme sunlight prevents the scanner from reading returning light pulses with precision and interrupts this process. Without resistance, intense light could cause the laser scanner to malfunction. That is why outdoor robots should be equipped with LiDAR sensors with high sunlight resistance.

Outdoor noise resistance

Sensors may have difficulty detecting obstacles due to certain environmental factors like precipitation, fog, or other translucent variables. In this situation, two types of laser beams come back to the sensor: one which reflects from the transparent object (i.e., rain, fog, dust) and the other which transmits through it and reflects on the sensor from the object beyond. Thus, it is necessary to choose a laser scanner capable of maintaining high-level accuracy even in conditions like rain, snow, dust, etc.

Hokuyo’s laser sensors have a multi-echo feature that enables the sensor to perceive two or more laser beams. Unlike a standard reflective sensor, this feature helps determine the distance and distinguish between close distance things like rain and the object which actually needs to be detected.

Obstructing electromagnetic interference

One of the key design considerations for outdoor robots is dealing with varying potencies and types of electrical noise coming from their surroundings. This noise can excite the sensors and circuits and disrupt the control system, causing the robot to malfunction or act erratically. In addition, electromagnetic disturbances can become troublesome for robots working around substations or powerlines. Therefore, this factor needs to be considered in the initial stages of the robot design process.

Hokuyo has designed LiDAR sensors that are competent to deal with this type of interference. Hokuyo laser sensors meet EN61000 standards of compatibility and are qualified to sustain in most EMC environments. With almost 80 years of experience in the automation industry, Hokuyo offers a wide range of LiDAR laser sensors with powerful capabilities.

Temperature resistance

Temperature range is another critical consideration that impacts the function of a laser scanner in an outdoor setting. Sensors could get damaged under intensely hot or cold temperature conditions. For this reason, it is advisable to look for laser sensors that involve a built-in temperature control system and a wide temperature range.

Hokuyo offers a lineup of LiDAR sensors with a range of features, including a heater function for application in low-temperature conditions. The temperature control system gets automatically activated when temperatures drop below zero degrees. At the same time, the heater aims to prevent frosting or moisture from penetrating the sensor so that it carries out operations even in below-freezing temperatures.

 

Reach out to us today and learn more about how our lineup of LiDAR sensors can provide superior performance for your unique outdoor robotic applications.