An Introduction to the Time-of-Flight Principle

Terabee is an expert in optical Time-of-Flight (ToF). For range-finding, ToF is very effective when emitting light when compared to sound. In comparison with ultrasound, it offers more rapid readings, far greater range, and greater accuracy while still maintaining low weight, small size, and low power consumption characteristics

Time-of-Flight Principle

The ToF principle is a technique for measuring the distance between an object and a sensor, depending on the time difference between the generation of a signal and its return to the sensor, after being reflected by an object. Several kinds of signals (also known as carriers) can be used with the ToF principle, the most widely used being light and sound.

TeraRanger sensors use light as their carrier as it can exclusively integrate longer range, lower weight, higher speed, and eye safety. The use of infrared light guarantees lesser signal disturbance and easier discrimination from natural ambient light, leading to the highest performing distance sensors for their specified size and weight.

TeraRanger sensors

Time-of-Flight Benefits

Small and Lightweight

TeraRanger ToF sensors are the ToF distance sensors with the lightest weight and smallest size available on the market at this performance level. (A TeraRanger Evo has a weight of just 9 g!) This indicates that sensors can be positioned in areas that were earlier impossible when using heavier, larger sensors. For mobile robotics, such as drones, this is a practical advantage!

TeraRanger ToF sensors

Long Range

Although they are small in size and light in weight, TeraRanger ToF distance sensors pack a strong performance punch! TeraRanger Evo can measure distances at around 60 m range. Moreover, this is achieved with LED technology and not a laser! (See the “LED Illumination” section.)

Fast Refresh Rates

TeraRanger ToF sensors are improved for high-speed readings. For example, TeraRanger Evo 600Hz can measure FIXED 600 readings within a second! Besides being lightweight and small, high data refresh rates are vital to the company’s design ethos, rendering the sensors suitable for fast-moving applications, from mobile robotics to industrial automation and smart city applications such as traffic monitoring and management.

TeraRanger ToF sensors

LED Illumination

Terabee uses Infrared LED technology rather than using laser emitters, resulting in numerous vital advantages.

Power consumption: In comparison with certain laser devices, LEDs use far less power — something that will be beneficial to all users who are dependent on battery power.

Field-of-view: Instead of measuring a very small point, the emitted light can be allowed to disperse and create a field-of-view. In several applications, this can be a unique benefit. Consider a sensor that is trying to identify a tree. Using a laser, one might detect the leaves, or penetrate the spaces and sense something much further away. In a robotics safety or anti-collision condition, this could result in serious problems. It is far more probable that the TeraRanger technology would detect the disaster that must be eliminated. Usually, at 1 m to the target, a TeraRanger One sensor measures an area almost 4 cm by 4 cm.

Eye safety: Under all conditions, TeraRanger sensors remain safe to eyes without requiring Laser Class 1 safety precautions!

TeraRanger ToF sensors

Easy to Use

Every TeraRanger sensor is plug-and-play. The need for performing customer calibration is eliminated; moreover, there is no need to convert complex outputs into distance readings. TeraRanger sensors just stream calibrated distance values in millimeters. The company makes efforts to compensate for environment variables like ambient light and temperature, automatically and immediately adapting to the conditions to offer the maximum performance.

Multiple communication protocols are supported by the sensors, and in a majority of the cases, upon connecting the sensor, it will automatically recognize the host computer’s communications protocol (typically Serial/UART or TWI/I2C) and load the corresponding firmware.

TeraRanger ToF sensors

Plug and Play Support for Multi-Sensor, Multi-Axis Use

A simple plug and play approach is provided to multi-sensor applications only by the TeraRanger technology. For instance, TeraRanger Multiflex offers 8 sensors connected to one flexible bus, whereas the TeraRanger Hub Evo enables around 8 TeraRanger Evo sensors to be connected, with the sensor synchronization, Hub centralizing power management, and communications. Sensors can be positioned in almost any direction, offering a quick and efficient approach for clients to form custom arrays and configurations.

TeraRanger ToF sensors

This information has been sourced, reviewed and adapted from materials provided by Terabee.

For more information on this source, please visit Terabee.


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