Radar scanner provides 3D data and improves object and spatial imaging

Radar technology is associated either with speed controls in road traffic or with air traffic control devices. However, since the 2000s, the technology has increasingly found its way into cars themselves. Active distance control systems, known as ACC (Adaptive Cruise Control) systems, use radar to determine the distance to cars in front and their speed. Radar has also become increasingly prevalent in industrial automation in recent years. In particular, its advantages over ultrasonic, opto-sensory, or media-contact technologies are paying off in many applications, especially in level and classic distance measurements.

In 2020, TURCK introduced its first radar sensors for level measurement with the LRS series, followed in 2021 by the DR-M30 radar sensors for distance measurement. Both device families operate in the 120 GHz range, which is particularly beneficial for range and resolution, i.e., signal accuracy. TURCK is now adding the MR15-Q80 radar sensor as the third member of its radar portfolio. The shape of the housing alone makes it clear that this is another type of device that complements the product range. In contrast to the cylindrical devices for distances and fill levels, the MR15-Q80 has a flat, rectangular design. The underlying technology is also different: Inside the robust IP69K housing is a 60 gigahertz antenna. Compared to the 120 GHz frequency band, the lower frequency provides less resolution, but the beam angle is significantly wider. The MR15-Q80 detects objects with an opening angle of 120 degrees horizontally and 100 degrees vertically.

The sensor has a range of up to an impressive 15 meters, although this maximum value may be reduced depending on the material, angle, and surface properties of the objects. However, since the target applications are primarily object detection and collision avoidance, users do not need to worry about insufficient range.

Collision control and object detection for mobile machines

TURCK's new radar scanner achieves maximum protection against water and dust ingress with IP69K and meets all requirements for the robustness of components for mobile equipment. The M15-Q80 also scores highly in terms of mechanical resistance, as it can withstand shocks and impacts of up to 100 g. This is where radar technology differs significantly from laser-based LiDAR technology. LiDAR systems require moving mirrors to direct the laser beams into every corner of the space to be scanned. These moving mirrors are naturally susceptible to mechanical damage from shocks and vibrations.

Radars are therefore not only less sensitive to interference factors such as dust, fog, or light reflections, but also much more robust mechanically. In addition to strong shocks, the MR15-Q80 also tolerates supply voltages of 12 or 24 volts, which are used in the on-board power supply systems of mobile machines – the sensor can even withstand possible voltage peaks without damage. TURCK positions the MR15-Q80 as a sensor for collision avoidance and object detection for all non-safety-related tasks. It detects objects in its environment and, unlike comparable devices, outputs measured values for all three dimensions. For mobile machines, the new radar scanner is currently the only device on the market that can output three-dimensional measurements via the SAE J1993 communication protocol for the CAN bus.

Realistic spatial imaging through 3D data

The MR15-Q80 provides distance and speed values for objects on all three spatial axes. This allows the environment and all objects within it to be mapped much more precisely. In particular, machines that operate at different heights with arms or booms receive valuable additional information about their surroundings. Thanks to the 3D information, the controller not only knows where an obstacle begins, but also where it ends and where the machine can operate with its arms. There are many other areas of application where precise knowledge of the space in front of machines can be helpful, for example in the detection of topography and rock protrusions in mining.

Identification of animals and objects in the field

Another application in the mobile equipment sector is the detection of animals and objects in fields. TURCK's radar scanner can be mounted directly on the threshing mechanism of a combine harvester to monitor the field in front of it. Due to the different reflection properties of animals or objects and grain stalks, the sensor can detect foreign objects in the field that could either be damaged themselves or damage the threshing mechanism. Thanks to its large cone angles of 120 degrees horizontally and 100 degrees vertically and a range of up to 15 meters, the radar scanner can reliably detect whether the field in front of the combine harvester can be harvested without any problems.

Six warning radii and three signal areas adjustable

For these and other applications, users can define warning radii that trigger a switching signal as soon as an object is detected within them. Switching signals can also be reliably triggered by specific intensity thresholds, which are important for distinguishing between objects. However, the controller can also evaluate the IO-Link signal completely in order to utilize the entire information density. Up to six freely definable warning fields and three three-dimensional signal spaces can be taught in and linked to one of the two switching outputs. If one of these warning fields is in the radar shadow because an object is located between the sensor and the field, the sensor also detects this and issues a corresponding message.

Another possible application on mobile machines is blind spot warning, i.e., monitoring areas around the machine that are difficult to see. If there are objects there, the vehicle could be damaged. Warning radii and signal spaces are also helpful for this purpose, enabling warning signals to be emitted in good time.

Collision avoidance in intralogistics

Alternative fields of application are also emerging in intralogistics. Industrial trucks and driverless transport systems (DTS) in particular require sensor technology for navigation and collision avoidance. LiDAR scanners are generally used for safety-related environment monitoring. However, these are only suitable to a limited extent for vertical monitoring of lifting paths on autonomous forklifts, as they usually have a small vertical cone angle. Special safety radars and scanners would also be oversized and therefore too expensive for the non-safety-related function of height control.

Height control

TURCK's 3D radar scanner provides the necessary information for all three spatial dimensions, enabling it to detect obstacles and the entire environment. This information also facilitates precise and safe control of lifting movements. The scanned data can also be used to ensure clearance heights and prevent damage to vehicles, goods, and system components. Camera systems are often used for these tasks, but they are more expensive and usually much more complex to commission.

Simplified commissioning and real-time visualization in TAS

The parameterization of such complex sensors, which output more than just an analog signal or one or two switching signals, often poses a challenge. TURCK supports users with its TAS (TURCK Automation Suite) configuration and IIoT software. The toolkit significantly simplifies commissioning and optimal adjustment of signal and intensity filters, detection angles, and warning radii. The software visualizes all raw sensor data in quasi-real time in a web browser. Objects are displayed as points and point clouds on two graphs, one for vertical data and one for horizontal detection angles.

TURCK offers two versions of the 3D radar scanner: one with IO-Link and one with SAE J1939 interface, which is primarily used for mobile machines. In addition to the interface for 3D data, both devices have two classic switching outputs that can be triggered by different threshold values.