RayRobo® Series

An OTA test system supporting full vehicle 5G MIMO measurement

Product Description

GTS's RayRobo® is an innovative test system designed around a mobile roboticarm. The system is an integrated design that is a movable full vehicle OTA

testing system. It can be an independent test system or be integrated into an existing automotive EMC chamber, so the EMC chamber can become a dual-functional system. When s tarting the automotive OTA test, RayRobo's electric car carries the robotic arm and its test probe, moves into the EMC chamber underneath the electrical controls. The test software automatically search and find the initial test point; the whole test process is automated. After the testing, the OTA system can move to the designated location, avoid any impact on EMC testing, and ensure dual function compatible with each other. RayRobo has strong applicability. With its precise "visual-recognition & assisted-positioning system", RayRobo can even perform the whole OTA measurement without a turntable. It will save the turntable construction and simplify system structure dramatically.

The system supports high-precision hemispherical scanning (θ angle between -1° and 110°), with millimeter-level motion accuracy. The scanning device can achieve rotation accuracy better than ±0.5°, fully meeting the current communication frequency band testing requirements. This scanning mode is suitable for vehicles within 6m×2m×2m, and can perform testing for various communication antennas. High-performance EPP hard foam absorbent materials are installed in critical parts of the mechanical arm, mobile platform, and ground to ensure repeated movement and transfer without deformation, powdering or crumbling, and absorbent performance degradation, thereby ensuring the long-term stable and reliable use of the testing system. The testing system also provides multiple options, reserving upgrade space to meet future testing needs.

The portable automotive OTA testing system consists of an electric control mobile car carrying an adjustable mechanical arm and a clamped testing antenna, which is a high-precision whole-vehicle-level OTA testing system guided by visual positioning and assisted positioning calibration. The system mainly includes the following parts:

Electronically controlled mobile platform

The platform uses AC220V/32A AC power supply, with wired and wireless control modes. There are 4 chakras on the bottom of the mobile platform, which can achieve movement in any direction. The car body is equipped with a liftable electric cylinder to support the entire car body and stabilize the chassis. The vehicle chassis is equipped with a visual positioning system to realize automatic driving of two-dimensional code navigation. The body comes with a level gauge. After the trolley moves to the designated position, the level of the body can be detected. It also supports feedback adjustment. It can support the four outriggers with one key and keep it level with the ground.

Test Rod

Used to connect the end of the robotic arm and the test antenna fixture, it is made of carbon fiber, light weight, high precision and high strength. The test rod is composed of four parts, the connector A holds the test antenna, and the cable passes through the middle; the connector B is connected to the port of the manipulator; the high-definition visual recognition calibration module on the connector B can perform XYZ axis for the position of the ground surface recognition point And the calibration of rx, ry, rz angles; high-definition high-resolution camera for visual positioning, can achieve accurate calibration of the B end of the connector.

Robotic Arm

The manipulator is imported from Switzerland, industrial grade manipulator, which has been widely used in automobile, ship and aircraft manufacturing. High precision and reliability.

Test Antenna

The car antenna test probe specially used for general testing is adopted, which has the characteristics of low RCS, wide beam width, high cross-polarization ratio, and low standing wave. The movable manipulator has a small footprint and is easy to move. It is equipped with two sets of telescopic systems. One is the 6-degree-of-freedom mechanical expansion and contraction of the manipulator. It can be retracted to less than 2.5m, so that the device can enter and exit the darkroom door with a height of more than 3m. Another telescopic system is the 4 outriggers that come with the mobile platform, which can be extended to a maximum of 2.5m×2.5m, which expands the force-bearing area and makes the robotic arm scanning more stable.

Features

Radiated Two-Stage (RTS) MIMO Testing

RTS is one of the two MIMO test methods approved by 3GPP/CTIA, and the general test has the RTS core patent. According to the characteristics of the vehicle test, we designed a special MIMO test scheme, using the radiation two-stage method to achieve accurate and efficient vehicle multi-antenna wireless performance test under complex electromagnetic environment. This solution supports 2×2/4×4 MIMO performance evaluation and is suitable for LTE and 5G sub6G (NSA/SA) communication systems. With the wireless channel emulator, dynamic MIMO tests under standard channel models can be performed, and even environmental simulations of rain, fog, terrain, dynamics, etc., as well as scenario road conditions can be simulated.

The advantages of moving the external environment into the darkroom are as follows:

  • Parameters can be controlled
  • model normalization
  • The scene can be repeated
  • test high efficiency

Desense vehicle self-interference diagnosis

When the car is driving, various internal subsystems will affect each other, and the receiving sensitivity of the wireless communication system will be interfered by various noises, and all sensitivity-related tests can use the Desense interference test method. In order to accurately analyze the influence of each module in the car and improve the wireless communication performance of the car, Desense test has become a key indicator of the whole vehicle test.

Test items with Desense test:

  • Influence of vehicle status on various communication performance
  • Influence of in-vehicle equipment on various communication performance
  • Influence of vehicle power supply on various communication performance
  • Dynamic influence

Wide beam, high cross-polarization measurement probe

For automotive testing, due to the near-field eccentricity, in order to ensure the accuracy of the measurement results, the main lobe of the test probe must effectively irradiate (that is, full coverage) the radiation position of the antenna under test (often the entire vehicle). The cross-polarization of the effective coverage beam is also the core index for the correct realization of the near-far field conversion. The eccentric system needs a high cross-polarization isolation to meet the near-far field conversion requirements. Since the automobile test needs to use the near-far field transformation, and one of the conditions of the near and far field transformation is to accurately distinguish the energy of the H polarization and the V polarization, the cross-polarization ratio of the entire main lobe energy of the test probe should be higher than 18dB, In order to meet the near-far field conversion test accuracy requirements. In order to achieve high-precision testing, Universal Test has designed an automotive-specific measurement probe.

Near and far field algorithm based on error analysis

The near-far field transformation algorithm is the core of the spherical near-field test system. The general test optimizes the traditional near-far field transformation process. With the unique probe design, it creatively solves the three major challenges of vehicle OTA testing – large tested objects. The problem of eccentric near and far field of parts; the problem of effective probe illumination, cross polarization and symmetry; the problem of probe factor calibration in near and far field restoration. This enables accurate evaluation of vehicle wireless communication performance

EPP Rigid Foam Absorber

The absorbing material is one of the core components of the anechoic chamber, and its performance and product quality have a direct impact on the overall indicators of the project. The full range of general testing products adopts the high-performance, environmentally friendly fourth-generation absorbing material based on the world’s leading technology – general testing patented technology polypropylene foam (EPP) absorbing material, which has the unparalleled performance of traditional polyurethane sponge (PU) materials. Advantages: moisture-proof, flame-retardant, stable and environmentally friendly.

The manipulator is imported from Switzerland, industrial grade manipulator, which has been widely used in automobile, ship and aircraft manufacturing. High precision and reliability.

Test Software

The Raytest Automotive Testing Software, independently developed by General Testing, provides a user-friendly results data display interface, including 3D/2D polar coordinates, 2D Cartesian coordinates, measurement data, raw data, test templates, and more. It covers a variety of measurement items including: passive antennas, 2G/3G/4G/5G SISO/MIMO, Wi-Fi, BT, V2X, and GNSS. The software introduces a plug-in development model, with a highly abstracted underlying architecture that can easily adapt to hardware changes. It can support multiple instruments and match different templates, making operation simple and easy to use.

The template linkage and provision of basic parameters reduce system complexity and make it easy for users to quickly use. It supports custom task queues and can achieve unmanned continuous testing. Raw data and log management are complete, and the measurement process is fully traceable.

The software provides dedicated automotive test data analysis and comparison software packages, supporting the analysis and comparison of various test data on ordinary configured computers, including:

  • Near-field test and far-field calculation data comparison
  • Comparison of test data from different vehicles
  • Comparison of simulated and measured data
  • 2D and 3D comparison from different angles
  • Comparison of data from multiple angles and frequencies
  • User-defined comparison.