How do you design a fake programmers
Real programmers are the cloud, big data, high load... And we have almost DIY. 2 installation — already duplication, 100 pieces — production... But nuclear-powered icebreakers, shunting locomotives, tractors, gateways, bridges, slip down of excess asphalt, drones the size of a house, 50 people staff in the shop longer than two kilometers... and reliability, reliability, reliability... And five CEOs in suits right on the field during the demonstration of the system on the tractor...
Normal termination debug — remove antenna puteprovodnoj machine
So... came the request from my colleagues to write the tap (technical and commercial bid) on the cunning of a GPS tracker. And comments that are real and large refused to do.
Hmm... we, of course, is GPS, but mildly different. Not trackers, and vysokochetkoe. Well as swaying bridge can measure. Or satellite compass to do. And trackers — not ours. But it is interesting to try where real refused!
the Main goal of this work is the implementation of p. 597 Federal norms and rules in the field of industrial safety "safety regulations for the mining and processing of solid minerals"
There is a quarry. Go on it mining shovels and trucks. And work people. Who knows — quarry machine large. From the cab — people are not visible. In recent years, with the customers a couple of accidents with human victims. Therefore we need a system to prevent collisions. That is a smart GPS trackers.
It is clear, as do large and real. GPS tracker via mobile communications (GPRS, 3G) transmits coordinates to the database server. The database server provides the coordinates to the application server, that determines the possibility of collision and on the Internet forwards alerts to the control room. From the control room, they somehow (SMS? Pager? The paging?) delegated to staff. Begin to think why refused large.
Yeah, already clear. The accuracy of household GPS receivers and GNSS — 3 meters CVO-50. That is 50% of the time — they give an accuracy of 3 meters, 49.8% — from 3 to 9 meters and 0.2% next. And TK likely is due 3 meters KVO-95. That is, 95% of the time error must be within a circle of radius 3 meters. Well, it's clear how to solve. Instead of home — take a semi-professional receiver that support DGNSS. It is such a system, when there is a stationary receiver with known coordinates. It calculates the error of the reception for each satellite and transmits this error to other receivers — mobile. And those already considered, given the known errors (primarily ionosphere). WOW! The project has emerged, the base station and communication channel base station receivers.
Receiver take the Russian-Ukrainian NV08C-CSM from KB Navis. Well, just because the authors are familiar. So, in case of problems consult. Look at the parameters in the mode DGNSS accuracy of 1 meter SKOthat is 1.7 meters CWE-95. Missed. And file the clearance is good.
What's next? Transmission via GPRS/3G. Read TK: operator Distance from the quarry to the cement clays is 7 km from the quarry of limestone is 100 km away.. Look at the map — what with the coverage of cellular operators? Who the hell knows what's in his career. On the surface — may be 3G, but at the bottom in his career... So the connection tracker with a base station by radio. Choose LoRa,well, I want our electronics to play with this technology because he's cheap and productive. At the same time — saving the customer on operating costs. To pay for 3 SIM cards is cheaper than 40.
Learn about the Internet — haven't seen him on these careers. What about communication with the dispatcher? So we need a GSM antenna on the mast. And not just the antenna, with amplifier. Remember Sochi and 1 packet every 20 minutes via GPRS. Though the season was, but in the evening the cell was filled with voice and GPRS slots. Then recall upgrade in St. Petersburg on the day that put the entire network Fora. No, one operator we know very little. Do 3 towers — each on your mobile operator.
And just 3 rigs — so 3 base stations and DGNSS 3 channels LoRa. Just got to the range with frequency division. However, temporal partitioning is probably better?
What's next at large? The application server defines the threat coming? And is it needed? But if the Internet is not? No, we are paranoid. The link trackers and base stations we have. The coordinates in the ether trackers transmit. Trackers each other listening. So the tracker can determine whether anyone near. And who is man or machine. And if he can't? Well, through mining truck radio may go bad. Means a safety system in base stations. They also analyze the approach and give the alarm to the tracker.
The DB server? Yes well itto the devil to the dispatcher. The mnemonic control room — draw Master SCADA on it and the same server. But the server and the mnemonic will manage better than us is their part in the overall project. And our trackers and base station.
Concept is already clear. Let's move on. Next, we have the power. Base stations — all good. Fed by 220 volts by cable. Shut off cable — not terrible, there are two. No electricity at all — well, at the very least, Munch-Munch-Munch, but the trackers will work. Dispatching is disabled, but the detection of dangerous proximity of people to technology will remain. With the loss of precision — but will remain.
And what's with the food trackers? Lithium battery as large? And how to change it when it runs out? These trackers send data once per second, they have the tracker mainly works in sleep mode. No, do meals on two 18650 batteries. And initially powered by a single, and after his full discharge from the other. To check the power — set button and led. Clicked — on means the norm. Flashes long — the right battery is discharged. Flashes briefly — both discharged. Well, the charging station to charge all night. Quarry works in the 1-2 shift, so overnight charging is. And is no night — just increase the number of batteries and bude to change them between shifts.
What trackers on cars? And here is the oscilloscope necessary. It is unclear whether they, too, from batteries to fuel, whether from the on-Board network + supercapacitor. The problem is that if the car is power on batteries to power supply from diesel — there is a surge and our devices crash. Need an oscilloscope to boatlifts, to understand that there is a shot. But for now, decide what vehicle electrical system better.
And that car with the antenna? Oops, the antenna is built into the tracker, will not work in a metal case. Well, or will be, but the signal will give poor and the accuracy will decrease. Means on the vehicle antenna external, and to have a General device for pedestrians and cars will not work.
Accordingly, we have three devices: a base station, the wearable tracker is battery powered with a built-in antenna and vehicle tracker with power from the electrical system and the roof antenna.
Then we have the drivers. The driver tracker is needed? Yes, it seems that need. If the driver got out of the car — it is to prevent the movement of other vehicles. What to do when boarding a car? Will be ringing constantly. Then you need to mute the ringing by pressing the button. At the same time solve the problem with the transportation by car. Approached the car, the tracker is ringing. I clicked on the button, the tracker paused until you exit 3хметровой zone.
And whether you want to track the truck on the way from the quarry to the railway-station or factory? Yes, like need, but this is optional. Put in car trackers 3G modems, but as an option. Price give higher — there's a "big" know better than us, let the customer they have a separate system buys.
Well, the line device is clear.
the
On buns, that is what we did not order, but thateasily can be done as an option:
What is left over? The budget of the radio channel. First of all, here research is needed on career. But one way or another we connection provide. And communication between trackers and base stations with trackers and base stations among themselves. At the very least, the base station will transmit in a circle, once every 3 seconds each. And the Rovers at every second. This is due to the fact that from the base station there is a stream about 25 times more than the Rover: the coordinates of all 20 Rover + DGNSS corrections.
PS As happens in 80% of cases, the tender was won by a private KB of the customer. Well, Yes, they in Bryansk, they have lower salaries and office rent is cheaper. Well, we are not mad. A few days on an interesting project and to work for free.
UPD1: By tip Wicron specify that alert pedestrians and drivers is done by feeding the audio signal (a call) through the buzzer.
UPD2: the review noted many who want to make the system collision warning and raids based on RFID. Alas, we were ordered not to "collision avoidance", we ordered step 597 the Federal norms and rules in the field of industrial safety "safety regulations for the mining and processing of solid minerals". A violation of these rules entails responsibility up to criminal. The article talking about 216. "Violation of safety rules at conducting mountain, building or other works"
Basic requirements:
the
The rules do not forbid a system based on radio, ulrazvuk, infrared sensors, but the transmission of information about the situation should go throughout a career. It is approximately 2.5 by 1.5 kilometers.
UPD3. At the request of TheShock write more about the budget of radio LoRa. Very Pro channel separation in LoRa a lot will not tell, but it is the frequency, code and temporary.
The problem is this. Each tracker reports 37 bits: 23 bits of the coordinate 8-bit speed 1 bit — SOS button, 5-bit — number of the tracker. The base station transmits the coordinates and velocities of all 20 trackers, that is, 620 bits + 30 bits of the amendments DGNSS +5 bits for the station number, only 655 bit. If all sit on one frequency channel only is transmitted 2035 bit. Between gears — protective intervals. In the end, will have to pass at a speed of 7 kilobits, if not more. But — the wide band transmission and 500 kHz.
There is another option. Each base station broadcasts on the frequency. On the same frequency to broadcast those receivers that close to her. Then the average case, we have 37*7 + 655 = 914 bits, and at worst 37*20 + 655 = 1295 bits. But the receiver code appears to select frequency channel, and base stations, the second and third receiver LoRa to listen to the channels to each other. And channels in this case at 125 or 250 kHz.
There is another option. Base stations operate on the same channel, but each sends 1 every 3 seconds. Then we will have 1295 a bit.
And what is the best option we know when we sign the contract, get accurate topographic maps of quarries and carry out computer modeling of visibility at different location of the towers. More precisely do not know.
Article based on information from habrahabr.ru
Normal termination debug — remove antenna puteprovodnoj machine
So... came the request from my colleagues to write the tap (technical and commercial bid) on the cunning of a GPS tracker. And comments that are real and large refused to do.
Hmm... we, of course, is GPS, but mildly different. Not trackers, and vysokochetkoe. Well as swaying bridge can measure. Or satellite compass to do. And trackers — not ours. But it is interesting to try where real refused!
the Main goal of this work is the implementation of p. 597 Federal norms and rules in the field of industrial safety "safety regulations for the mining and processing of solid minerals"
There is a quarry. Go on it mining shovels and trucks. And work people. Who knows — quarry machine large. From the cab — people are not visible. In recent years, with the customers a couple of accidents with human victims. Therefore we need a system to prevent collisions. That is a smart GPS trackers.
It is clear, as do large and real. GPS tracker via mobile communications (GPRS, 3G) transmits coordinates to the database server. The database server provides the coordinates to the application server, that determines the possibility of collision and on the Internet forwards alerts to the control room. From the control room, they somehow (SMS? Pager? The paging?) delegated to staff. Begin to think why refused large.
Read paragraph 597
597. When you use the positioning tools to ensure safe operation of technological transport and mining equipment, speed control and mutual arrangement of mining tools and Executive mechanisms following conditions are met:
continuous transmission of coordinates and velocities of movement in the control room with the display of the navigation parameters on the terminal operators;
the positioning accuracy.
The accuracy of positioning should be:
for career road transport and bulldozers — not more than 3 m;
for rail transport — not more than 1 m;
for actuators drilling rigs and mining equipment — not more than 0.1 m;
for staff — no more than 3 m.
Staff located at the site of mining operations shall be equipped with individual means of positioning with continuous transmission of the location of the personnel in the control room.
The software should provide a timely alarm, alerting staff of danger of collisions, possible assaults, approaching hazardous areas, breaches of the technological parameters and modes of operation of mining equipment.
continuous transmission of coordinates and velocities of movement in the control room with the display of the navigation parameters on the terminal operators;
the positioning accuracy.
The accuracy of positioning should be:
for career road transport and bulldozers — not more than 3 m;
for rail transport — not more than 1 m;
for actuators drilling rigs and mining equipment — not more than 0.1 m;
for staff — no more than 3 m.
Staff located at the site of mining operations shall be equipped with individual means of positioning with continuous transmission of the location of the personnel in the control room.
The software should provide a timely alarm, alerting staff of danger of collisions, possible assaults, approaching hazardous areas, breaches of the technological parameters and modes of operation of mining equipment.
Yeah, already clear. The accuracy of household GPS receivers and GNSS — 3 meters CVO-50. That is 50% of the time — they give an accuracy of 3 meters, 49.8% — from 3 to 9 meters and 0.2% next. And TK likely is due 3 meters KVO-95. That is, 95% of the time error must be within a circle of radius 3 meters. Well, it's clear how to solve. Instead of home — take a semi-professional receiver that support DGNSS. It is such a system, when there is a stationary receiver with known coordinates. It calculates the error of the reception for each satellite and transmits this error to other receivers — mobile. And those already considered, given the known errors (primarily ionosphere). WOW! The project has emerged, the base station and communication channel base station receivers.
Receiver take the Russian-Ukrainian NV08C-CSM from KB Navis. Well, just because the authors are familiar. So, in case of problems consult. Look at the parameters in the mode DGNSS accuracy of 1 meter SKOthat is 1.7 meters CWE-95. Missed. And file the clearance is good.
What's next? Transmission via GPRS/3G. Read TK: operator Distance from the quarry to the cement clays is 7 km from the quarry of limestone is 100 km away.. Look at the map — what with the coverage of cellular operators? Who the hell knows what's in his career. On the surface — may be 3G, but at the bottom in his career... So the connection tracker with a base station by radio. Choose LoRa,
Learn about the Internet — haven't seen him on these careers. What about communication with the dispatcher? So we need a GSM antenna on the mast. And not just the antenna, with amplifier. Remember Sochi and 1 packet every 20 minutes via GPRS. Though the season was, but in the evening the cell was filled with voice and GPRS slots. Then recall upgrade in St. Petersburg on the day that put the entire network Fora. No, one operator we know very little. Do 3 towers — each on your mobile operator.
And just 3 rigs — so 3 base stations and DGNSS 3 channels LoRa. Just got to the range with frequency division. However, temporal partitioning is probably better?
What's next at large? The application server defines the threat coming? And is it needed? But if the Internet is not? No, we are paranoid. The link trackers and base stations we have. The coordinates in the ether trackers transmit. Trackers each other listening. So the tracker can determine whether anyone near. And who is man or machine. And if he can't? Well, through mining truck radio may go bad. Means a safety system in base stations. They also analyze the approach and give the alarm to the tracker.
The DB server? Yes well it
Concept is already clear. Let's move on. Next, we have the power. Base stations — all good. Fed by 220 volts by cable. Shut off cable — not terrible, there are two. No electricity at all — well, at the very least,
And what's with the food trackers? Lithium battery as large? And how to change it when it runs out? These trackers send data once per second, they have the tracker mainly works in sleep mode. No, do meals on two 18650 batteries. And initially powered by a single, and after his full discharge from the other. To check the power — set button and led. Clicked — on means the norm. Flashes long — the right battery is discharged. Flashes briefly — both discharged. Well, the charging station to charge all night. Quarry works in the 1-2 shift, so overnight charging is. And is no night — just increase the number of batteries and bude to change them between shifts.
What trackers on cars? And here is the oscilloscope necessary. It is unclear whether they, too, from batteries to fuel, whether from the on-Board network + supercapacitor. The problem is that if the car is power on batteries to power supply from diesel — there is a surge and our devices crash. Need an oscilloscope to boatlifts, to understand that there is a shot. But for now, decide what vehicle electrical system better.
And that car with the antenna? Oops, the antenna is built into the tracker, will not work in a metal case. Well, or will be, but the signal will give poor and the accuracy will decrease. Means on the vehicle antenna external, and to have a General device for pedestrians and cars will not work.
Accordingly, we have three devices: a base station, the wearable tracker is battery powered with a built-in antenna and vehicle tracker with power from the electrical system and the roof antenna.
Then we have the drivers. The driver tracker is needed? Yes, it seems that need. If the driver got out of the car — it is to prevent the movement of other vehicles. What to do when boarding a car? Will be ringing constantly. Then you need to mute the ringing by pressing the button. At the same time solve the problem with the transportation by car. Approached the car, the tracker is ringing. I clicked on the button, the tracker paused until you exit 3хметровой zone.
And whether you want to track the truck on the way from the quarry to the railway-station or factory? Yes, like need, but this is optional. Put in car trackers 3G modems, but as an option. Price give higher — there's a "big" know better than us, let the customer they have a separate system buys.
Well, the line device is clear.
the
-
the
- base station: a GNSS receiver, a 3G modem, a mast, a GNSS antenna, 3G antenna, 3G booster, power supply (220 for 5 and 12 volt), radio LoRa, LoRa antenna, processor Renesas OS linux. the
- Wearable tracker: GNSS receiver, GNSS antenna, radio LoRa, LoRa antenna, STM32 processor, FreeRTOS, buzzer, button, led, 2 batteries. the
- Automobile tracker: GNSS receiver, radio LoRa, 3G modemSTM32 processor, FreeRTOS, buzzer, button, led, 2 batteries.
- the
- In the house at the checkpoint: a charging station and night storage wearable trackers. There's also a brace of remote controller, receiving data through the Internet with the Scud.
On buns, that is what we did not order, but that
-
the
- signal SOS with wearable and mobile trackers; the
- Receive paging signals (up to 4 options of signals); the
- Scanner to determine the direction of a buried collapse people; the
- Geomonitoring of landslides on the sides of the quarry; the
- Geomonitoring edges career; the
- Adaptive polling frequency (from 1 Hz to 1 times per minute) to carry the tracker, depending on the possibility of collisions. Including while in the car; the
- Router to share the Internet in prokurennom house; the
- Providing several operator workstation by installing the breeder data; the
- Analysis of historical data (tracks and crashes).
What is left over? The budget of the radio channel. First of all, here research is needed on career. But one way or another we connection provide. And communication between trackers and base stations with trackers and base stations among themselves. At the very least, the base station will transmit in a circle, once every 3 seconds each. And the Rovers at every second. This is due to the fact that from the base station there is a stream about 25 times more than the Rover: the coordinates of all 20 Rover + DGNSS corrections.
PS As happens in 80% of cases, the tender was won by a private KB of the customer. Well, Yes, they in Bryansk, they have lower salaries and office rent is cheaper. Well, we are not mad. A few days on an interesting project and to work for free.
UPD1: By tip Wicron specify that alert pedestrians and drivers is done by feeding the audio signal (a call) through the buzzer.
UPD2: the review noted many who want to make the system collision warning and raids based on RFID. Alas, we were ordered not to "collision avoidance", we ordered step 597 the Federal norms and rules in the field of industrial safety "safety regulations for the mining and processing of solid minerals". A violation of these rules entails responsibility up to criminal. The article talking about 216. "Violation of safety rules at conducting mountain, building or other works"
Basic requirements:
the
-
the
- continuous transmission of coordinates and velocities of movement in the control room with the display of the navigation parameters on the terminal operators; the
- position accuracy 3 meters the
- Staff located at the site of mining operations shall be equipped with individual means of positioning with continuous transmission of the location of the personnel in the control room. the
- the Software should provide a timely alarm, alerting staff of danger of collisions, possible assaults, approaching hazardous areas, breaches of the technological parameters and modes of operation of mining equipment.
The rules do not forbid a system based on radio, ulrazvuk, infrared sensors, but the transmission of information about the situation should go throughout a career. It is approximately 2.5 by 1.5 kilometers.
UPD3. At the request of TheShock write more about the budget of radio LoRa. Very Pro channel separation in LoRa a lot will not tell, but it is the frequency, code and temporary.
The problem is this. Each tracker reports 37 bits: 23 bits of the coordinate 8-bit speed 1 bit — SOS button, 5-bit — number of the tracker. The base station transmits the coordinates and velocities of all 20 trackers, that is, 620 bits + 30 bits of the amendments DGNSS +5 bits for the station number, only 655 bit. If all sit on one frequency channel only is transmitted 2035 bit. Between gears — protective intervals. In the end, will have to pass at a speed of 7 kilobits, if not more. But — the wide band transmission and 500 kHz.
There is another option. Each base station broadcasts on the frequency. On the same frequency to broadcast those receivers that close to her. Then the average case, we have 37*7 + 655 = 914 bits, and at worst 37*20 + 655 = 1295 bits. But the receiver code appears to select frequency channel, and base stations, the second and third receiver LoRa to listen to the channels to each other. And channels in this case at 125 or 250 kHz.
There is another option. Base stations operate on the same channel, but each sends 1 every 3 seconds. Then we will have 1295 a bit.
And what is the best option we know when we sign the contract, get accurate topographic maps of quarries and carry out computer modeling of visibility at different location of the towers. More precisely do not know.
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