This article lists and describes in detail most modern solutions ensuring control of fuel consumption for Vehicle Oh. This information will allow you to expand your knowledge of the types of equipment used, and will allow you to take a more balanced and rational approach to the choice of control methods and purchased measuring instruments. Using this material You will certainly be able to avoid unnecessary costs for experiments.
Modern methods of monitoring fuel consumption and other parameters in transport.
First, let's answer a few questions, the solutions to which we will consider individually below.
Which facilities typically require the use of fuel consumption controls?
- passenger vehicles
- freight transport
- special equipment
- agricultural machinery
- stationary tanks for storing and dispensing fuels and lubricants
What types of fuel do they usually want to monitor?
- diesel fuel
- petrol
- GAS (propane, butane)
Which modern methods and methods for monitoring fuel consumption exist?
- connect to the vehicle's standard analog fuel level sensor
- connect to vehicle injector
- connect to CAN bus vehicle
- install a fuel level sensor in the vehicle tank
- install a flow-through fuel meter on the vehicle engine
- install an ultrasonic fuel level sensor (US) on the vehicle tank or LPG cylinder
- install a fuel level sensor on the gas cylinder to control the gas level
Now let's look at each control method separately....
Monitoring fuel level and consumption using a standard analog sensor.
Here is another example of how a fuel meter is installed on an engine. It doesn't take much time.
If the customer is against loopback (changes) fuel system You can install differential fuel meters on both fuel lines (supply and return) at once. You can install a differential meter, for example, after the fuel pump low pressure), both fuel streams of the vehicle are conveniently located nearby. IN in this case It is worth remembering that meters are afraid of dirt, so it is advisable for a differential fuel consumption control meter to install an additional filter in front of the meter in the supply line so that dirt from the bottom of the tank does not get into it.
If the fuel meter is clogged, there is nothing to worry about. They can be cleaned in just 15 minutes. An example of how this is done can be found in the “reference book” of the “info center” on our website. Regardless of the type of meter and its manufacturer, the technology is the same. For example "Cleaning (flushing) of the flow fuel meter VZO 8 (OEM)" or "Cleaning (flushing) of the flow fuel meter VZO 4 (OEM)".
Whatever meter you choose to monitor vehicle fuel consumption, you must take into account that fuel meters are susceptible to water hammer from the injection pump. These water hammers can create errors in measurements; to avoid this, an additional one must be installed after the meter. check valve or a hose ring at least 2 meters long.
Another nuance of using differentiated fuel consumption monitoring meters is that they are not suitable for all vehicles. To some vehicle at the outlet of the fuel injection pump from diesel fuel Foam is formed from the pressure difference, and this foam is incorrectly counted by the fuel meter. You can fight it with defoamers or diaerators, but it doesn’t always help. In this case, it is better to choose a different method of control.
The fuel meter only monitors the fuel actually consumed by the engine; the vehicle tank remains uncontrolled. In this case, there is no need to rely on control of fuel fillings and drains.
Diagram for installing a fuel pressure meter:
Scheme for installing the fuel meter for discharge:
Installation diagram of a differential fuel meter:
Fuel level monitoring using ultrasonic sensors (ultrasound).
Ultrasonic fuel consumption monitoring sensors operate on the FLS principle (they measure the fuel level in the vehicle tank), only you do not need to drill into the tank to install them. This equipment is installed from below fuel tank by attaching an ultrasound emitter. These systems today are not cheap. The only advantage is that there is no need to make a hole in the tank. The disadvantages include the following: the ultrasonic fuel control sensor (US) is sensitive to dirt at the bottom of the tank and to the presence of water. The reason lies in the method of measuring the fuel level in a vehicle tank using an ultrasound sensor. The fact is that the signal from the emitter is reflected from the difference in the transmission medium of the ultrasound wave. In other words, the sensor passes through the level of diesel fuel in the tank and is reflected on the upper boundary (air), and the electronics, recording these readings, determines the height of the fuel level in the tank. If other media appear in the path of the emitter (water at the bottom of the tank or a particle of debris floating along the bottom of the tank), reflection will occur earlier and lead to a false fuel level value. This is not a big deal once, the GLONASS satellite monitoring program will filter out these readings, but if there is a lot of garbage and the tanks get clogged frequently, this can lead to a serious error. After installing an ultrasonic fuel consumption monitoring sensor, the vehicle tank must also be calibrated.
The working principle looks something like this:
Or in this video you can see how similar work is done on site.
Monitoring the gas level in the LPG cylinder using an external sensor.
A lot of our clients are interested in the issue of monitoring gas consumption on commercial vehicles. It is clear that technologically it is not realistic for drivers to drain GAS. They steal here simply by “under-refueling” or at the same time refueling their car. Plus the addition of mileage, plus overestimation of consumption standards, in the end - despite the significant difference in price from other types of fuel, GAZ has firmly taken its place in the list of fuel frauds.
As a rule, gas consumption on a vehicle is monitored by the driver based on the kilometers traveled and a mechanical sensor located on top of the LPG cylinder. Extremely inconvenient, of course, but there is no choice. Recently it has appeared gas equipment With electronic sensors, readings from which are displayed on various indicators of the gas level in the cylinder, or directly in standard systems TS. These sensors work extremely inaccurately, with jerks, jumps, etc.
Ordinary mechanical sensor The gas level on the HBO cylinder usually looks like this:
It can be replaced with an analogue one, also with an indication and an analogue output for the GLONASS monitoring system. After installation gas cylinder it is also necessary to calibrate, as a result, in the GLONASS transport monitoring system it will be possible to monitor the state of the gas level in the LPG cylinder, as a result of the actual fuel consumption and refueling. Now variants of fraud will be stopped. It looks like this after installation:
Also, to ensure control of gas consumption on vehicles, you can use control over the vehicle injector, or install an ultrasonic sensor (ultrasound) - these methods were described above, so we will not waste time on this again.
When implementing fuel consumption monitoring equipment, regardless of the type of control and equipment manufacturer, it is worth understanding the main thing - it will only work correctly installed equipment! Fuel consumption monitoring systems lead to significant savings and are very different short terms payback period (no more than three months, and often this is a month)! As a result of installing such equipment, the flow error can be reduced to the minimum possible indicator - 1% -3% no more. And before installing fuel consumption monitoring systems at enterprises, this error is at least 10%, and often reaches 30% (sometimes higher). Also, we must not forget that at gas stations they do not add enough fuel and the fuel trucks that bring fuel and lubricants to the enterprise are also being cunning! Using fuel monitoring systems, you can stop fuel theft by drivers, identify and control fuel suppliers, and also see which gas stations operate honestly and which ones cheat. All this together leads to restoration of order and enormous savings of money.
This data is based on our 10 years of implementation experience similar systems. Don't believe me? Take the equipment to FREE test drive!
There are a lot of modern ways to control fuel consumption on vehicles. Which solution should you choose? Weigh the pros and cons yourself or take our advice. We do not charge money for consultations. Specialists of the company "STAVINTEKH" will select for you optimal solution monitoring the operation of the vehicle, at a price and the required measurement accuracy. Most equipment is available for FREE trial use! Want to check how it works? Contact
One of the variants of the device, which allows you to control the amount and speed of liquid (in particular fuel) flowing through the line, was described in the article by I. Semenov et al." Electronic flow meter liquids" ("Radio", 1986, No. 1).
The repetition and adjustment of this flow meter is associated with certain difficulties, since many of its parts require high precision processing. Its electronic unit needs good noise immunity due to high level interference in on-board network car. Another disadvantage of this device is the increase in measurement error with decreasing fuel flow rate (in idle move and low engine load).
The device described below is free from the listed disadvantages and has more simple design sensor and circuit electronic unit. It does not have a device for monitoring the rate of fuel consumption; its function is performed by a total consumption meter. The frequency of operation is proportional to the rate of fuel consumption and is perceived by the driver by ear. This does not distract from driving, which is especially important in city traffic.
The flow meter consists of two components: a sensor with an electrovalve built into the fuel line between the fuel pump and carburetor, and an electronic unit located in the vehicle interior. The design of the sensor is shown in Fig. 1. Between the body 8 and the tray 2, an elastic diaphragm 4 is clamped, dividing the internal volume into upper and lower cavities. The rod 5 moves freely in the guide sleeve 7 made of fluoroplastic. The diaphragm is clamped at the bottom of the rod with two washers 3 and a nut. A permanent magnet 9 is installed at the upper end of the rod. In the upper part of the body, parallel to the channel in which the rod is located, two additional channels. They are equipped with two reed switches 10. In the lower position of the magnet, and therefore of the diaphragm, one reed switch is triggered, and in the upper position, another.
Fig.1. 1-Fitting, 2-Pan, 3-Washers, 4-Diaphragm, 5-Stem,
6 - Spring, 7 - Bushing, 8 - Housing, 9 - Magnet, 10 - Reed switches
The diaphragm moves to the upper position under the influence of fuel pressure coming from the fuel pump, and spring 6 returns it to the lower position. To connect the sensor to the fuel line, three fittings 1 are provided (one on the pan and two on the body).
The hydraulic diagram of the flow meter is shown in Fig. 2. Through channel 3 and the solenoid valve, fuel from the fuel pump enters channels 1, 2 and fills the upper and lower cavities of the sensor, and through channel 4 enters the carburetor. The valve is switched under the influence of signals from an electronic unit (not shown in this diagram), controlled by a reed switch of the sensor.
Fig.2
In the initial state, the solenoid valve winding is de-energized, channel 3 communicates with channel 1, and channel 2 is closed. The diaphragm is in the lower position, as shown in the diagram. The fuel pump creates excess fluid pressure in the lower cavity 6. As the engine produces fuel from the upper cavity A sensor, the diaphragm will slowly rise, compressing the spring.
When the top position is reached, reed switch 1 will operate and the electrovalve will close channel 3 and open channel 2 (channel 1 is constantly open). Under the action of a compressed spring, the diaphragm will quickly move down to its original position and release fuel through channels 1, 2 from the cavity b V A. Then the flow meter operation cycle is repeated.
The electronic unit (Puc.3) is connected to the sensor and solenoid valve with a flexible cable through the XT1 connector. Gorkoms SF1 and SF2 (1 and 2, respectively, according to Fig. 2) are installed in the sensor (in the diagram they are shown in a position where the magnet does not act on any of them); Y1 - valve solenoid winding. In the initial position, transistor VT1 is closed, contacts K1.2 of relay K1 are open and winding Y1 is de-energized. The sensor magnet is located next to the SF2 reed switch, so the reed switch does not conduct current.
Fig.3
As fuel is consumed from the cavity A sensor, the magnet slowly moves from reed switch SF2 to reed switch SF1. At some point the SF2 reed switch will switch, but this will not cause any change in the block. At the end of the stroke, the magnet will switch the reed switch SF1 and the base current of the transistor VT1 will flow through it and resistor R2. The transistor will open, relay K1 will operate and contacts K1.2 will turn on the valve solenoid, and contacts K1.1 will close the power supply circuit of the pulse counter E1.
As a result, the diaphragm together with the magnet will begin to quickly move down. At some point the reed switch SF1 after reverse switching will break the base current circuit of the transistor, but it will remain open, since the base current now flows through the closed contacts K1.1, diode VD2 and reed switch SF2. Therefore, the rod with the diaphragm and magnet will continue to move. At the end reverse the magnet will switch the reed switch SF2, the transistor will close, the valve electromagnet Y1 and the counter E1 will turn off. The system will return to its original state and a new cycle of its operation will begin.
Thus, counter E1 records the number of sensor activation cycles. Each cycle corresponds to a certain volume of fuel consumed, which is equal to the volume of space limited by the diaphragm in the upper and lower positions. The total fuel consumption is determined by multiplying the meter readings by the amount of fuel consumed in one cycle. This volume is set when calibrating the sensor. For the convenience of measuring fuel consumption, the volume per cycle is chosen to be 0.01 liters. If desired, this volume can be slightly reduced or increased. To do this, it is necessary to change the distance between the reed switches in height. With the specified sensor dimensions, the optimal aperture stroke is approximately 10 mm. The duration of the sensor cycle depends on the engine operating mode and ranges from 6 to 30 s.
When calibrating the sensor, it is necessary to disconnect the pipeline from the car's gas tank and insert it into a measuring vessel with fuel, and then start the engine and produce a certain amount of fuel. Dividing this amount by the number of cycles on the counter, the value of the unit volume of fuel per cycle is obtained.
The flow meter has the ability to turn it off using toggle switch SA1. In this case, the sensor diaphragm is constantly in the lower position and fuel through channels 2 and 3 through cavity a will directly flow into the carburetor. To realize the possibility of turning off the device in the solenoid valve, it is necessary to remove the rubber cuff covering channel 3, but this will worsen the error of the flow meter.
The electronic unit is mounted on a printed circuit board made of fiberglass 1.5 mm thick. The board drawing is shown in Fig. 4. The parts installed on the board are outlined in the diagram with a dot-dotted line. The board is mounted in metal box and is mounted in the car interior under the instrument panel.
Fig.4
The device uses a RES9 relay, passport PC4.529.029.11; solenoid valve - P-RE 3/2.5-1112. Counter SI-206 or SB-1M. Permanent magnet You can use any one with an end arrangement of poles and a length of 18...20 mm, it is only necessary that it moves freely in its channel without touching the walls. For example, a magnet from a remote switch RPS32 will do; you just need to grind it down to the required size.
The sensor body and tray are machined from any non-magnetic petrol-resistant material. The wall thickness between the channels of the reed switches and the magnet should not be more than 1 mm, the diameter of the hole for the magnet is 5.1+0.1 mm, the depth is 45 mm. The rod is made of brass or steel 45, diameter - 5 mm, length of the threaded part - 8 mm, total length- 48 mm. The thread on the sensor fittings is M8, the hole diameter is 5 mm, and on the solenoid valve fittings there is a conical thread K 1/8" GOST 6111-52. The spring is wound from steel wire with a diameter of 0.8 mm GOST 9389-75. The diameter of the spring is 15 mm, pitch - 5 mm, length - 70 mm, force full compression- 300...500 g.
If the rod is made of steel, then the magnet is held on it due to magnetic forces. If the rod is made of non-magnetic metal, then the magnet must be glued or strengthened in any other way. To ensure that the operation of the sensor is not interfered with by the pressure of air compressed above the magnet, a bypass channel with a cross-section of about 2 mm2 should be provided in the bushing.
The diaphragm is made of polyethylene film 0.2 mm thick. It must be molded before installation into the sensor. To do this, you can use the sensor pan assembled with a fitting. It is necessary to make a technological clamping ring from sheet duralumin 5 mm thick. The shape of this ring exactly matches the assembly flange of the pallet.
To form the diaphragm, the rod assembly with its blank is inserted with inside into the hole of the pallet fitting and clamp the workpiece with a technological ring. Then the assembly is evenly heated from the diaphragm side, holding it above the burner flame at a distance of 60...70 cm and, slightly lifting the rod, the diaphragm is formed. In order for the diaphragm not to lose elasticity during operation, it is necessary that it is constantly in the fuel. Therefore, when long-term parking car, it is necessary to clamp the hose from the sensor to the carburetor to prevent evaporation of gasoline from the system.
The sensor and solenoid valve are installed on a bracket in engine compartment near the carburetor and fuel pump and are connected with a cable to the electronic unit.
The performance of the flow meter can be checked without installing it on the car using a pump with a pressure gauge connected instead of a fuel pump. The pressure at which the sensor is triggered should be 0.1 ... 0.15 kg/cm2. Tests of the flow meter on Moskvich and Zhiguli cars have shown that the accuracy of measuring fuel consumption does not depend on the engine operating mode and is determined by the error in setting a unit volume during calibration, which can easily be adjusted to 1.5...2%.
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| VT1 | Bipolar transistor | KT608B | 1 | To notepad | ||
| VD1-VD4 | Diode | KD105B | 4 | To notepad | ||
| HL1 | Light-emitting diode | AL307B | 1 | To notepad | ||
| R1 | Resistor | 1.5 kOhm | 1 | 0.5 W | To notepad | |
| R2 | Resistor | 1.2 kOhm | 1 |
The scope of application of our meters is departmental mini gas stations, as well as individual use. We will help you organize a system for recording the consumption of diesel fuel, gasoline, kerosene and machine oil. By controlling the amount of petroleum products sold and keeping statistics on their consumption at your enterprise, you can save significantly.
Classification of fuel consumption meters
Counters liquid fuel have certain design features depending on the product whose consumption they measure. Taking into account the degree of viscosity, chemical composition and the presence of suspended impurities, the device can be made from various materials and have different designs. For example, meters for gasoline and kerosene are equipped with special Viton gaskets.
The following options for flow meters are available:
Diesel fuel (diesel fuel) meter.
Oil meter.
Gasoline meter.
Kerosene meter.
Refueling pistol with counter.
Fuel pump with meter.
Our metering devices can be installed on a mini fuel supply pipe gas station or boiler room, as well as on the burner or mounted in the filling nozzle.
Today, the industry produces two main types of fuel transfer meters:
Mechanical counter.
Electronic counter.
As the name suggests, the first type of design is completely mechanical. The second type of counter uses digital, electronic method calculation and indication of consumed fuel volume. Both mechanical and electronic meters have their pros and cons. Mechanical design gives a large measurement error (about 1%), but works flawlessly in the harsh Russian winter. Electronic meters are more accurate (accuracy is about 0.5%), but they do not work well in the cold, as they are designed for European winters with frosts no more than -5ºС. Shutdown threshold electronic filling for some manufacturers it ranges from -10ºС to -30ºС.
Therefore, if refueling of vehicles at your enterprise takes place in the open air, then it would be preferable to use mechanical fuel refueling meters, especially in winter period. In order to increase the measurement accuracy of meters, they are often installed together with fuel pump. Due to this connection, fuel is supplied to the meter with constant pressure, which ensures minimal error.
Reliable manufacturers of fuel consumption meters with whom we work
Having been working in the fuel equipment supply market for several years, our company has established long-term partnerships with three well-known manufacturing companies. These are Gespasa (Spain), Petroll (China) and Piusi (Italy). The products of these brands have only positive reviews from customers and the optimal combination of price, quality and reliability. If we compare the meters we supply with analogues on the market from Fill-Rite and Adam Pumps, the latter will be less effective in a number of indicators, and also much more expensive.
Let's give brief characteristics fuel meters produced by our partners.
Mechanical counters. Spanish Gespasa fuel consumption meters are economical and easy to use. They are designed to control the volume of pumped petroleum products in the non-commercial sector. The measurement accuracy is about 1% (may vary depending on the amount of fuel pumped). These mechanical counters have two indicators. The first scale displays information about the current measurement (can be reset to 0), and the second scale displays the total volume of all measurements since the counter was installed (cannot be reset). Using the calibration screw, you can restore the accuracy of measurements. The counter is equipped with a filter that prevents suspended impurities from entering the mechanism. All holes are threaded with a diameter of 25 mm.
Main advantages:
The design allows these meters to be installed in different positions.
Durable body material.
Compact and light weight.
High reliability.
Electronic meters. These counters have the same purpose as mechanical ones. However, they are more accurate. The measurement error is 0.5%. The devices are powered by electric batteries, which last for several years. By analogy with mechanical counters, electronic counters have two scales - a resettable current scale and a non-resetable general scale. The digital indicator can operate in winter conditions at temperatures down to -30ºС!
Mechanical counters. These are non-commercial, economical fuel meters with measurement accuracy up to 1%. The design is equipped with a calibration screw, two reading indicators (resettable current and non-resettable total) and threaded holes with a diameter of 25 mm. The device indicator can be rotated in any convenient direction.
Design advantages:
Unpretentiousness to operating conditions allows these meters to operate successfully in temperature range+50 ºС -30 ºС.
The impact-resistant case reliably protects the structure from mechanical influences.
The use of fittings allows you to install these devices not only with pumps, but also on fuel hoses.
Petroll electronic fuel meters are designed for garages, workshops and small vehicles. Non-commercial use is intended. They have small dimensions. The counters are equipped with two indicators - to display current and total measurements. The measuring element has a turbine design. The power supply is a battery with a long service life. The diameter of the threaded holes is 25 mm.
Mechanical meters from Piusi have oval gears, which increases measurement accuracy. They are reliable, economical and easy to use. The mechanical strength of the case and the absence of electronics allows these devices to be used even in the most severe conditions. There are two indication scales. Measurement error – 1%.
Electronic meters. Just like mechanical counters, electronic devices from Piusi have oval gears (measurement accuracy 0.5%). Aluminium case has increased strength. Power supply from batteries. Two scales display the current and total consumption of petroleum products.
All fuel meters supplied by us have wide range measurements:
20 – 120 liters per minute for low and medium capacity models.
30 – 800 liters per minute for industrial meters.
The quality of the equipment we offer is confirmed by the manufacturer's guarantee. The devices are pre-calibrated, tested and fully ready for use. The product catalog on our website will give you the opportunity to choose and buy any fuel consumption meter, taking into account your individual needs.
Having your own service center, the company Technord LLC is ready to provide warranty and service maintenance Total model range products. The company's managers are always happy to provide clients with the necessary technical advice and help in choosing equipment. If necessary, our specialists will install, calibrate and verify the meter.
Designs for monitoring vehicle operating parameters have advanced significantly over last years. They have become more functional, more technologically advanced and simply closer to to the mass consumer. Accounting systems fuel consumption for now they occupy a peripheral place in the general niche of transport electrical engineering, but this area is of interest to everyone large quantity car enthusiasts. Against this background, it is quite logical that fuel flow meters appear, operating on different principles. It is also practiced self-production similar ones which, of course, have their own specifics.
General information and characteristics of flow meters
Most of these devices are traditional small-sized meters, the design of which is designed for installation in the fuel system. The dimensions of a typical device can be represented as follows: 50 x 50 x 100 mm.
This is a small block with throughput 100-500 l/h. The average error is 5-10%. During the flow of liquid, the device records in one way or another the indicators of the sensitive element and stores the received data. The implementation of the system of accounting, control and presentation of information may be different. For example, a flow-through fuel flow meter for a car is made with the expectation of manual readings. It may have a mechanical panel with data display or link to a liquid crystal display digital display in the cabin, but the information is not processed by the on-board computer. More technologically advanced devices also allow for the possibility of electronic accounting in automatic mode. Depending on the flow dynamics, for example, on-board equipment can adjust certain parameters of the machine components and assemblies.
Types of devices
The classification is based precisely on the principle of taking into account readings, which is determined by the sensitive element. Today, the following flow meters for cars are distinguished:
- Coriolis. The operating principle is based on the Coriolis effect, in which the dynamics of the phases of mechanical vibrations in the tubes through which the fuel circulates is measured.
- Turbine. A blade device is integrated into the system, the rotation of the blades of which is converted into speed indicators. Thus, taking into account the parameters of the serviced channels, the volume of consumption is determined.
- Geared. Another type of mechanical fuel flow meter that records data through rotating elements. In this case, a compact gear, the movement of which allows you to record flow data.
- Ultrasonic. These are meters of a new type that do not contact the target medium at all, but record the parameters of changes in the characteristics of the fuel system based on acoustic waves.
Features of diesel meters
Heavy fuel is usually used by trucks and special equipment, which place higher demands on fuel metering devices. The operating principle is usually mechanical. Moreover, the design of the sensors has more high degree insulation - for example, with Thus, the device is protected from the effects of an aggressive environment. The housing can be formed by an aluminum solid alloy, the measuring chambers of which are also provided with anti-friction coatings. The flow meter is located both in the fuel mixture supply line and in the return channel through which the liquid returns to the tank. Only if both circuits are covered can accurate data on consumption volume be obtained.
Additional functionality
The presence of a GPS monitoring system is perhaps the most modern addition to fuel consumption sensors. Such devices allow you to transmit information on-board computer over a wireless channel. Multifunction devices can comprehensively record flow data in several systems simultaneously. The main one can be taken into account fuel mixture and with additives and modifiers. The benefit of comprehensive monitoring is the ability to accurately control additives for fuel, transmission and other systems. In addition, it may be provided different modes operation of devices. There are fuel flow meters that, in addition to the function of counters, perform idle control tasks, record possible temperature overloads and, based on the information received, regulate climatic equipment. When introducing the device into the signaling infrastructure, the flow sensor may well be programmed to perform the tasks of monitoring the heater and the engine auto-start system.
Installation of flow meters
The devices are installed in the target metering loop through a physical insertion into the channel. And here it is important to emphasize that, depending on the car model, the fuel channels may initially have remote pipes with plugs, which can be used precisely as integration points for metering devices. It should also be taken into account that installation is carried out behind the filtration system. This solution will prevent possible contamination of the fuel flow meter and its premature exit out of service.
Mechanical fixation of massive devices is usually carried out on a complete frame, which is attached to the surface of the body. According to reviews from car enthusiasts, it is important to calculate so that the sensitive channel is sufficiently interfaced with the target environment, and the base of the housing can be securely fixed to the mounting platform with hardware. It is advisable that the installation location does not involve strong vibration loads and thermal influences.
Self-production of flow meters
According to drivers, it is quite difficult to assemble a full-fledged meter completely from scratch, and for this you need to have certain knowledge in radio engineering. However, based on a ready-made control unit such as a controller and sensor with an electric valve, the task is simplified. The sensor itself is integrated into the fuel line. It should be placed between the fuel pump and carburetor. As for the control unit, it is connected to the detector and output to the cabin. Using the CAN interface, you can connect your own fuel flow meter to the on-board electronics. As additional elements Mounting and controlling the sensor may require the use of fittings, washers, trays and bushings. The technical infrastructure must be designed to respond autonomously when the fuel pump opens.
How to fool the fuel flow meter?
Standard meters for monitoring gasoline or diesel consumption can be adjusted in one direction or another. The simplest way involves draining through the return line. It is enough to insert a fitting into this channel and drain the liquid through a hidden circuit. In some configurations, the built-in line may be used for a direct supply function, in which case the fuel flow meter meters simply will not provide up-to-date information. Another option provides thermal effect to the sensor. This applies specifically to liquid level detectors, which, after a thermal burn, stop working correctly, although outwardly they look intact. You can pour boiling water over the device or bring a heater to it for 5-10 minutes. But before doing this, it is worth thinking about the feasibility of such experiments.
Hello! I'll tell you about my attempt to make an onboard flow meter based on Arduino Nano. This is my second product from Arduino, the first was a walking spider. After experimenting with light bulbs and servos, I wanted to do something more useful.
Of course, you could buy a finished product, maybe even for lower price(although I couldn’t find it for less). But it wasn't fun, and it might not have the features I wanted. In addition, a hobby, like sports, rarely justifies the costs in material form.
Before I talk about the process, I’ll show you a picture of what it looks like now. The program is still in the debugging stage, so the controller hangs on wires in the cabin, and the display is stuck on double-sided tape) In the future, this will be installed humanly.
The device calculates and displays kilometer fuel consumption on the display: instantaneous on the bottom line, average over the last kilometer on the top line.
The idea of making this thing came to me a long time ago, but it was hampered by the lack of information about what and how it works in my car. I have it quite old - Corolla E11 with a 4A-FE engine. I knew about the engine that it is fuel-injected and that the injectors have more or less constant performance, which is what its own control unit counts on. Therefore, the main idea of measuring flow is to measure the total duration of opening of the nozzles.
ECU, as suggested good man and as the instructions later confirmed, it controls the injector in the following way: plus is always supplied to it, and minus opens and closes depending on the wishes of the ECU. Therefore, if you connect to the negative wire of the injector, you can track the moment of its opening by measuring the potential: when the ECU shorts the injector to ground, 14 volts drop to zero. This simple thought did not immediately occur to me, because my knowledge of electronics is limited to a school physics course and Ohm’s law. Next, we needed to turn +14V into +5V, which can be supplied to the logic input of the controller. Here I somehow came up with a shunt circuit known to all electronics engineers, but before that I had to study the manuals and make sure that the injector resistance was negligibly small, and the logic input resistance was almost infinite.
To calculate the kilometer consumption, it was necessary to obtain data from the speed sensor. Everything turned out to be simpler with it, because it produces steps 0... +5V, the more steps, the more mileage. These steps went directly to the logical input without transformations.
I really wanted to display data on the LCD display. I was considering different variants and settled on a MELT text display for 234 rubles based on the Hitachi HD44780 microcontroller, which Arduino has been able to work with since birth.
After long and painful reflection, the following diagram was drawn up:
In addition to resistors that reduce the voltage from the injector, there is a voltage stabilizer here in order to power the controller from the on-board network, as well as on the advice of grandfather and good friend capacitors were added to smooth out possible voltage peaks, and a resistor “just in case” for each logical input. And yes, I decided to send signals from the injector and sensor to analog inputs, which I later did not regret at all, because in digital mode the analog inputs did not want to understand the difference between a closed and open nozzle, but in analog they showed very clearly different level voltage. Perhaps this is a flaw in my scheme, but everything was done for the first time, blindly and without testing on a breadboard, in general, at random.
Following the diagram, I added markings printed circuit board(yes, I immediately rushed to type, because I didn’t really want to mess around with a bunch of wires on the circuit board):
The board was etched for the first time and with some technology violations, so the result came out so-so. But after tinning everything came back in order. I etched using a laser iron, learned from well-known videos on easyelectronics. After etching the board turned out like this:
To solder the elements onto the board, we had to make a lot of holes in it. I didn’t want to buy an expensive drill like a Dremel or similar, and in order to save a couple of thousand rubles, I made a micro drill from a motor and a collet clamp, which were bought at a radio store nearby:
After drilling holes, tinning and soldering, the board began to look like this:
Here I foolishly soldered an extra stabilizer, which was later replaced with a resistor.
After the product was ready, I began testing it in combat conditions, that is, directly on the car. To do this, at my request, the wires from the injector and sensor were routed into the cabin. For the microcontroller I wrote test program, which wrote raw data to the COM port - the number of pulses from the speed sensor and the milliseconds during which the injector was open. After sitting in the car with my laptop and seeing that the data corresponded to reality, I was incredibly happy and went home to write a working version of the program.
After two or three testing sessions, the program began to show valid data. At first I calculated average consumption according to the time interval (5-10 minutes), which caused an interesting effect: after five minutes of standing at a traffic light (not even a traffic jam, but a slight semblance), the kilometer consumption jumped to prohibitive values of 50-100 liters per 100 km. At first I was perplexed, but then I realized that this is a common thing, because the consumption is per kilometer, and I average it over time: the clock is ticking, gasoline is flowing, and the car is standing still. After that, I came up with the bright idea of averaging by mileage: in the current version, the program calculates how much gasoline was consumed in the last kilometer and shows how many liters will be consumed if you drive 100 km at the same pace. The “instant” flow rate is calculated as the average for the last second and is updated every second.
Source code (if anyone is interested) I
