CZ28625U1 - Unit for interpolation of GNSS signal of advisory vehicle system - Google Patents

Description

GNSS Advisory Vehicle System Interpolation Unit

Technical field

The solution relates to the technical implementation of a vehicle unit to support testing and development of a unified concept of an advisory power management system for various vehicle drive system configurations, based on evaluation of inertial systems connected to the vehicle bus, GPS / GLONAS vehicle satellite position knowledge, receiving RTK corrections via private radio network and knowledge of vehicle dynamics. The unit can be used in many industrial areas, especially in the area of location and vehicle navigation systems development.

BACKGROUND OF THE INVENTION

One important factor in improving the energy efficiency of vehicle systems is the integration of controls. This requires the development of a new generation of specific testing tools. The GNSS advisory vehicle system (Global Satellite Position System) signal interpolation unit extends the limits of vehicle position refinement based on inertial vehicle data. The main benefit of the GNSS signal interpolation unit lies in the development and testing of Human Machine Interface (HMI) systems for improved driving stability and improved environmental performance. Nowadays, technology for determining the current position of the vehicle off the road is becoming increasingly important. For positioning we can use different kinds of technologically different approaches, for example: GNSS satellite system, positioning by GSM network of mobile operator, inertial vehicle systems, infrastructure location system 20 or various combinations of these approaches. The most accurate location data of a moving object can be obtained through a satellite navigation system using a network of ground stations transmitting a differential correction signal. However, even this method does not allow positioning in shaded areas such as tunnels, dense urban areas, etc. A certain solution is a combination of GSM cellular network and satellite positioning A-GPS (network-assisted GPS).

To make the satellite system more accurate in locations with low satellite signal levels, GSM base stations can also be used. This system also has its limitations in terms of base station availability and positioning accuracy. These shortcomings were the basis for the development of a new GNSS signal interpolation unit for the vehicle guidance system.

Significant disadvantages of existing location devices when developing vehicle assistance systems include:

- Limited accuracy depending on the number of signals received from satellite transmitters

- Dependence on infrastructure conditions - topological layout of the road, surrounding development, presence of underground transport structures

- Limited frequency of location data provision

- Reduced / limited transmission of signal reception, eg windscreen, etc.

- Possibility of deliberate interference (selective availability)

List of literature:

Gakstatter, E.: Centimeter-Level RTK Accuracy More and More Available, http://gpsworld.com/centimeter-level-rtk-accuracy-more-and-more-available-for-less-andless/,

11. Nov. 2014

Beutler, G .: GPS and GNSS from the International Geosciences Perspective; ILRS; p. 17-22 Rapant, P .: Satellite Position Systems. VŠB-TU Ostrava, 2002, 200 pp. ISBN 80-248-0124-8 The essence of technical solution

The object of the solution is to create a hardware and firmware unit enabling positioning of the vehicle with centimeter accuracy and frequency of 50 Hz (and higher) using a conventional system

-1 CZ 28625 Ul

GPS / GLONAS. The GNSS signal interpolation test unit consists of two parts: an inertial system consisting of a three-axis gyroscope and a three-axis accelerometer and an ARM data evaluation unit. Positioning is determined based on vehicle motion sensing using an inertial system, CAN (Control Area Network) bus data, GNSS satellite system data, receiving Real Time Kinematic (RTK) corrections via a private radio network, and knowledge of vehicle motion dynamics.

Optionally, steering wheel motion and vehicle GPS position data from an automated robotic steering system can be utilized. The inertial system is mounted on the roof structure of the vehicle with three GNSS antennas and data cables connected to the ARM data evaluation unit. Second pulses (1PPS) from one of the three GNSS antennas (optional) entering the ARM data evaluation unit are used to synchronize the inertial system time with UTC (Coordinated Universal Time) time obtained from GNSS satellite position sensors.

The ARM data evaluation unit is further connected to an on-board power supply. The output data from the ARM data evaluation unit is sent to the serial port through which the ARM data evaluation unit is connected to the data logger. Longitudinal and yawing speed of the vehicle is important to refine the position of the vehicle. These data are provided from inertial sensors that are rigidly connected to the roof structure of the vehicle, where the sensor axes are identical to the vehicle axes. To further refine the position, the selected values from the CAN bus are recorded, in particular the values of the speed of the individual wheels, the accelerator pedal, the brake system pressure and the steering angle.

The required minimum positioning frequency of 50 Hz corresponds to a period of 20 ms, when the exact reading time is recorded. Practical tests have shown that the datalogger timestamps may not be suitable for this task, so each ARM data record data record also contains its own timestamp. The ARM data evaluation unit includes an internal clock that does not require parameter setting. Their value always increases incrementally from zero when the ARM data evaluation unit is switched on. For each rising edge of the second pulse (1PPS), the internal clock state is stored, which corresponds to the start of the second in UTC. Synchronization of internal time with UTC time can then be performed retroactively by means of data logger recording. The ARM data evaluation unit is equipped with signaling LEDs to indicate the operation of each interface. The LED changes its status (on or off) when an event occurs on the interface.

The output of the ARM data evaluation unit is a 2D UTM coordinate position and UTC time:

- the position of the real measured points of three GNSS receivers

- interpolated positions

Advantages of this technical solution:

New applications are offered in particular with respect to stored position and kinematic data, which, with respect to a uniform timeline, allow direct assessment of the technical causes of system behavior.

The main benefit of the proposed solution is positioning with high accuracy and frequency of recording when testing the limits of vehicle dynamics and driver response, which allows feedback in assessing stability and driving comfort systems. This GNSS signal interpolation test unit can be used in the commercial field of vehicle assistance systems as standard vehicle equipment or as additional vehicle installation. Unlike the collision mitigation assistance systems, this system can be applied in general to all road users (pedestrians, cyclists, motorcyclists, rail vehicles, etc.). In combination with prediction algorithms, this unit can take over the vehicle's directional warning function which, when testing a variety of vehicle assistance systems: FCW Forward Colision Waming, LDW Lane Departure Warning System (Waming), LCDI Warning Systems for

-2256251 UL (Decision Change Aid), etc., provides wide spectrum use.

Application of GNSS signal interpolation outputs is designed for the following areas:

- in the automotive industry as a basis for testing on-board assistance systems to monitor the inappropriate reactions of motor vehicle drivers. In particular, these systems will be retrofitted. Furthermore, as an add-on module of vehicle simulators, it is possible in laboratory conditions to verify the psychological aspects of driver decision-making in relation to the topological layout of the road. This unit, in connection with the wireless communication module, would also find application as part of a transport infrastructure system aimed at increasing active safety or charging for selected road sections.

- the basis for the development and testing of new generations of vehicle positioning systems using satellite technologies such as GALILEO.

Clarification of the drawing

An exemplary embodiment of the present invention is illustrated in the accompanying drawing, in which Figure 1 is a diagram of a GNSS signal interpolation unit of an advisory vehicle system. The enclosed arrows represent the data transfers between the different parts of the unit, distinguishing whether it is a one-way or two-way data transmission. Optional accessories are shown in blue. In black, the basic accessory unit for the GNSS signal interpolation system of the VLT is indicated.

Example of technical solution implementation

Figure 1 shows an exemplary embodiment of a technical solution, which is a GNSS signal interpolation unit of an advisory vehicle system. The unit consists of two parts - a roof unit and an indoor unit located in the vehicle cockpit containing an ARM data evaluation unit consisting of a CP processor, a DS memory containing program instructions for calculating vehicle position, and an SL interface for signaling LEDs to indicate operation of each interface. SPI for the first GNSS receiver from SA1 antenna, SP2 interface for the second GNSS receiver from SA2 antenna. SP3 interface for third GNSS receiver from SA3 antenna, NP interface for vehicle power supply via vehicle MIC via microphone connector MIC, DL interface for connection to datalogger recorder, KS interface for receiving RTK corrections via private radio network in band 350 to 470 MHz and a set of interfaces KB1 - KB5 connectable via the BNC connector to the On-board Controller Area Network with a KB1 interface for sensing the accelerator pedal deployment from the On-board Controller Area Network (CAN); KB3 interface for sensing steering angle from on-board bus, KB4 interface for sensing speed of individual wheels from on-board bus, KB5 interface for sensing lateral acceleration and yaw rate from ESP (Elect ronic Stability Program) from the on-board vehicle bus, with the roof unit consisting of a three-axis GS gyroscope and a three-axis AK accelerometer. which are mounted on the roof structure of the vehicle together with three GNSS antennas and through the SPI serial interface to connect the first GNSS receiver with SAJ antenna, the serial SP2 interface to connect the second GNSS receiver with SA2 antenna and the SP3 serial interface to connect the third GNSS receiver with SA3 antenna connected via data line to the ARM data evaluation unit.

An ARM data evaluation unit containing a CP processor for processing, evaluating and interpolating the current vehicle position is connected via data cables to a three-axis gyroscope GS and a three-axis accelerometer AK. A data logger is connected to the ARM data evaluation unit via the DL serial interface to store data from each ARM data processing unit interface together with synchronization data based on UTC time of one of the three GNSS receivers (optional) and CP internal time integrated in the

-3GB 28625 UI ARM Data Evaluation. The power supply of the NPM for data evaluation ARM is realized from the vehicle power supply network via the MIC screw connector. Positioning by the ARM data evaluation unit is determined based on algorithms describing the vehicle motion kinematics stored in the DS memory, data from attached equipment consisting of a 3-axis GS gyroscope and a 3-axis accelerometer AK for sensing longitudinal and yaw rate of the vehicle. Control Area Network) connected through a twisted-pair data line enabling the accelerator pedal position to be sensed through the KB1 interface. sensing brake system pressure via KB2, steering wheel angle sensing via KB3, sensing individual wheel speed via KB4, transverse acceleration and yaw sensing from ESP via KB5, and data from three satellite GNSS receivers connected via SPI, SP2 interface. SP3 interface and also based on RTK corrections sent via private radio network via RS interface.

Optionally, the advisory vehicle GNSS signal interpolation unit is supplemented via RR interface with an input from an automated robotic steering system for steering and sensing steering wheel movement and GPS reception with an RS radio relay network for transmitting RTK correction signal over distances up to several tens of kilometers connected via KS interface and also OS power transmission sensor for measuring circumferential and transverse forces on the wheel.

The output message from the ARM data evaluation unit is generated every 20 ms and sent via the DL serial interface to the datalogger data logger. All data is converted to an appropriate format so that the report fully complies with the National Marina Electronic Association (NMEA) standard, that is, data in a text representation with a maximum length of 80 characters. Individual values are formatted in hexadecimal numbers. With on-board bus messages with KB1 interface for sensing the position of the accelerator pedal, with KB2 interface for sensing brake pressure, with KB3 interface for sensing steering wheel angle, with KB4 interface for sensing wheel speed, with KB5 sensing interface lateral acceleration and yaw rate from the ESP unit combines the first 31 characters, a further 24 characters are associated with data from an inertial system consisting of a three-axis gyroscope GS and a three-axis accelerometer AK and the remaining 16 characters with a time stamp generated by the CP processor integrated in the ARM data evaluation unit.

List of literature:

[1] Hogan, Michael K., Advanced mission planning tool for real-time cinematic (RTK) GPS surveying [2] Czommer, Renate, Leistungsfahigkeit fahrzeugautonomer Ortungsverfahren auf der Basis von Map-Matching-Techniken

Claims (5)

PROTECTION REQUIREMENTS 1. An advisory vehicle system GNSS signal interpolation unit, comprising a processor (CP) to which is connected an inertial system located on the roof of a vehicle comprising a three-axis gyroscope (GS), a three-axis accelerometer (AK), and a processor (CP). CP) connected through the serial interface (SPI) of the first of three GNSS receivers with antenna (SA1), through the serial interface (SP2) of the second GNSS receiver with antenna (SA2) and through the serial interface (SP3) of the third GNSS receiver with antenna (SA3); a plurality of interfaces (KB1) - (KB5) for connection to the vehicle bus are connected to the processor (CP), with an interface (KB1) for sensing the position of the accelerator pedal, with an interface (KB2) for sensing the brake system pressure; ) for sensing steering angle, with interface (KB4) for sensing the speed of rotation of individual wheels, with interface (KB5) for sensing the transverse the acceleration and yaw speeds from the ESP [Electronic Stability Program], which are located in the cockpit of the vehicle -4GB 28625 UI interface (SL) for connecting LEDs to indicate operation of each interface, memory (DS) containing program instructions for calculating vehicle position, power supply (NP) from the vehicle's mains network, interface (DL) for connection to data logger for continuous cloud recording of information clouds, interface (KS) for receiving RTK corrections sent over a private radio network in the 350 to 470 MHz band, with the set of interfaces (SPI) - (SP3) and (KB1) - (KB5) arranged for transmission a synchronizing second pulse that is parametrically adjustable, preferably synchronous with UTC time, wherein the processor (CP) is arranged to generate and send a NMEA standard message via a serial interface (DL) to the data logger recording unit, an inertial system located on the roof of the vehicle is provided at level h RS-485 differential bus to reduce the influence of the vehicle's disturbed environment. The GNSS signal interpolation unit of claim 1, wherein the processor (CP) is connected to an interface (RR) for input from an automated robotic steering system to control and sense steering wheel movement and receive an external GPS signal. The GNSS advisory vehicle system signal interpolation unit according to any one of the preceding claims, characterized in that the processor (CP) via an interface (KS) for receiving RTK corrections is connected to an input from a retransmission network (RS) formed by radio modems for transmitting the correction signal over longer transmission distances up to tens of kilometers. A GNSS signal interpolation unit for vehicle guidance system according to any one of the preceding claims, characterized in that a power transmission sensor (OS) for measuring circumferential and transverse forces on the wheel is connected to the processor (CP). The GNSS advisory vehicle signal interpolation unit according to any one of the preceding claims, characterized in that the NMEA messages in conjunction with vehicle bus data are intended to calculate a vehicle position with a frequency of at least 50 Hz, in other words for GNSS signal interpolation. 1 drawing List of reference marks: GS - three-axis gyroscope AK - three-axis accelerometer SA1, SA2, SA3 - three GNSS receivers with antenna SPI, SP2, SP3 - three serial interfaces for connecting GNSS receivers DS - memory CP - processor SL - interface for connection of signaling LEDs, indicating operation of individual interfaces NP - power supply from vehicle mains DL - interface for connection to data logger ŘR - interface for input from automated robotic control system for controlling and sensing steering wheel movement and receiving external GPS signal KS - interface for receiving RTK corrections sent through a private radio network in the band 350 to 470 MHz RS - retransmission network consisting of radio modems for transmission of correction signal over longer transmission distances up to tens of kilometers OS - force transmission sensor for measuring circumferential and transverse forces on the wheel KB1 - vehicle bus interface for sensing the accelerator pedal position KB2 - vehicle bus interface for sensing brake system pressure KB3 - vehicle bus interface for steering angle sensing KB4 - vehicle bus interface for speed sensing of individual wheels KB5 - vehicle bus interface for sensing lateral acceleration and yaw rate from the unit ESP.