RU218350U1 - Multifunctional sensor module for satellite navigation - Google Patents

Abstract

The utility model relates to the field of radio direction finding, namely to satellite radio navigation systems, and can be used to determine the location, as well as other parameters such as temperature, acceleration, structural integrity. The objective of the utility model is to expand the range of operating temperatures of the sensor module, up to -55°C. A multifunctional sensor module for satellite radio navigation, containing a microcontroller, a satellite communication module, a mobile communication module, an accelerometer, characterized in that it additionally contains a temperature stabilization unit containing two groups of resistors: the first - for controlling the shoulders of the Wheatstone bridge - resistors, thermistor, the second - for the actual heating, high power; an operational amplifier and one or two power transistors. 2 ill.

Description

The utility model relates to the field of radio direction finding, namely to satellite radio navigation systems and can be used to determine the location, as well as other parameters such as temperature, acceleration, structural integrity.

A known device for obtaining location data /1/. For this, a GLONASS (GNSS) receiver is used, as well as a microcontroller controlling the system. In addition, there is a voltage stabilization circuit up to 3.3 V, necessary for the operation of the device. Information enters the device and from it through several connectors, which also make it possible to change the program for the operation of the device.

This solution has a number of disadvantages: Lack of autonomous operation, the possibility of external intervention and reprogramming of the device operation, lack of protection against temperature extremes, especially continued operation at temperatures below zero. In addition, this solution does not have additional functions, in addition to satellite navigation.

Also known device /2/. This solution contains a GNSS/GPS module for positioning, a GSM module for data transmission, an accelerometer that takes into account device acceleration, and a 4.5 mAh battery. The device has two tiers, on which the printed circuit board and power elements are located. The author's idea is also to minimize the volume of the module, the volume of the model is 105 cm ³ . In addition, the author indicates an alternative version of the utility model with an alarm button and a temperature sensor. This gives an understanding that the system was developed, including for security purposes.

The problem with this solution is a weak level of resistance to changing temperature. The module is able to work only within the limits of the extreme values of functioning laid down in the hardware, without possible improvements in this area.

The objective of the utility model is to expand the range of operating temperatures of the sensor module, up to -55 degrees Celsius.

For this, a useful model of a multifunctional sensor module for satellite radio navigation was proposed, containing a microcontroller, a satellite communication module, a mobile communication module, an accelerometer, which differs from the prototype in that it additionally contains a temperature stabilization unit containing two groups of resistors - the first to control the shoulders of the Wheatstone bridge, the second - for actual heating, an operational amplifier and one or two power transistors, which makes it possible to prevent the temperature from falling below the declared operating temperatures of the module elements.

The satellite communication receiver has the ability to work with satellite systems such as GLONASS, GPS, Galileo, QZSS, SBAS (WAAS, EGNOS, GAGAN, MSAS). This enables the most stable operation in conditions of disconnection or lack of signal reception from priority sensors. Also, within the framework of the device there is an antenna, which is fixed inside the case, which makes its fastening more reliable and unaffected by external factors.

The device uses a microcontroller as a control circuit, which performs all calculations, reception, transmission and accumulation of data received from sensors.

The GSM module is capable of both receiving data, such as settings, in order to change the operating parameters of the device, and transmitting sensor data received from the microcontroller or alarm signals. The GSM module operates at frequencies of 850, 900, 1800, 1900 MHz. An antenna is also used for this module.

A feature of the module is the presence of a temperature stabilization unit, which makes it possible to use the device at extremely low temperatures, and taking into account positive temperatures, the device operates within -55 ... + 60 ° С. A feature of the block is also considered to be its autonomous operation relative to the rest of the circuit. That is, the permanent operation of the functional part of the sensor module is not necessary for the operation of the temperature stabilization unit.

In FIG. 1 shows a block diagram of the module operation, where:

1-antenna of the mobile communication module,

2 - mobile communication module,

3 - antenna of the satellite communication module,

4 - satellite communication module,

5 - non-volatile Flash memory,

6 - battery,

7 - voltage stabilization unit,

8 - microcontroller,

9 - accelerometer,

10 - temperature stabilization unit,

11 - temperature sensor.

In FIG. 2 shows a block diagram of the temperature stabilization unit (10), where

12 - the first arm of the Wheatstone bridge,

13 - the second arm of the Wheatstone bridge,

14 - operational amplifier,

15 - power transistors,

16 - high power resistors.

The system is controlled by a microcontroller (8).

A satellite navigation module (4), a mobile communication module (2), as well as their antennas (3.1, respectively) are connected to it via information channels. In addition, an accelerometer (9) is connected to the microcontroller, which transmits indications about the presence of device accelerations. There is a non-volatile Flash-memory (5), which stores information from sensors within the module and external sources. The module also uses a temperature sensor. The entire module is powered by a battery (6), from which energy is supplied to the voltage stabilization unit (7). A feature of the module is the temperature stabilization unit (10), which is also considered in Figure 2.

Within its framework, there are two arms of the Wheatstone bridge (12,13). Next is the operational amplifier (14), and a group of power transistors (15). Heating occurs with the help of high power resistors (16).

The operation of the module is based on the operation of a microcontroller that controls all peripheral devices and sensors. The module includes a temperature sensor and an accelerometer. It is possible to connect external sensors via the I2C bus.

With a large array of data, a 64 MB (or 32 MB) Flash memory is used, which makes it possible to write 2048 (or 1024 with 32 MB of memory) times more than in the microcontroller. It is estimated that when using the standard variable size of 4 bytes, it is possible to record 16 million events (8 million with 32 MB of memory).

With, for example, 8 sensors (3 axes of the accelerometer, internal temperature sensor, charge level, 3 external temperature sensors) and a recording frequency of 0.5 s, it makes it possible to accumulate data for 291 hours, to fully write the Flash memory, and then overwrite them, leaving in memory 291 (145 with 32 MB of memory) hours of the previous operation of the device.

The module uses a satellite communication module that has the ability to receive data from GLONASS, GPS, Galileo, QZSS, SBAS (WAAS, EGNOS, GAGAN, MSAS) satellites. If there is no priority satellite in range, the microcontroller gives a command to switch to another type of satellite. This allows you to receive data with high stability.

To transmit the received and accumulated information, a GSM mobile communication module is used, operating at frequencies of 850, 900, 1800, 1900 MHz. Within the framework of the utility model, the transmission of data within the framework of encrypted text messages is conceived. In addition to the above, thanks to the GSM module, it is possible to change the settings during the operation of the module.

In accordance with the task, within the framework of the sensor module there is a temperature stabilization unit. It consists of the two arms of the Wheatstone Bridge. A thermistor is inserted into one of the arms, the resistance of which varies depending on the temperature of its environment. When the temperature threshold is reached, the resistance drops so much that the total resistance of the arm becomes less than the total resistance of the second arm. This creates a slight difference in tension between these shoulders. An op amp installed next changes the operating mode by switching to another state. The voltage falls on a group of power transistors, which open and the current, passing through high power resistors, heats up the module. At the same time, taking into account the design, the module becomes able to provide a temperature difference between the external environment and the temperature inside the device. In this regard, the main task of the module is achieved - functioning in a wide range of operating temperatures.

The device adopts an ADC-10 (JIS) grade aluminum housing, which also prevents exposure to external influences. This brand of aluminum is an analogue of ENAC-AISi9Cu3(Fe), the tensile strength of which is 240 MPa. This solution makes the author's solution very resistant to external influences. In addition, the solution has protection against dust and water at the level of IP67.

The technical and economic feasibility of the solution is illustrated by an example: when the prototype falls into the temperature range from -30°C and below (depending on the component base used), the device will not be able to maintain error-free functionality, and after reaching -40°C, its functionality in general. In contrast, the described utility model, upon reaching temperatures below -30°C, begins to react to this, namely, the temperature stabilization unit begins to react. The operation of the unit raises/maintains the overall temperature of the module for full error-free operation.

Information sources:

1. Patent of the Russian Federation No. 71489

2. RF patent No. 193444 - prototype

Claims (1)

A multifunctional sensor module for satellite radio navigation, containing a microcontroller, a satellite communication module, a mobile communication module, an accelerometer, characterized in that it additionally contains a temperature stabilization unit containing two groups of resistors: the first - for controlling the shoulders of the Wheatstone bridge - resistors, thermistor, the second - for the actual heating, high power; an operational amplifier and one or two power transistors.

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