Accelerometer sensors are widely applicable as a reliable and accurate measure of acceleration forces. This article overviews accelerometer sensors’ types, applications, and installation methods. It explains the different types of accelerometer sensors, ranging from piezoelectric to servo, and the various areas where we can apply them, such as car accident alarms and monitoring galloping of high voltage wires. Additionally, this article provides a detailed description of the installation process and the various mounting methods that one can use to attach the accelerometer sensor to a surface. With this information, engineers can use accelerometer sensors to create reliable and accurate systems for measuring acceleration forces.
What is an Accelerometer sensor?
An accelerometer sensor measures acceleration. Typically, an accelerometer sensor consists of dampers, elastic parts, sensitive parts, adaptive circuits, and masses. During acceleration, the sensor measures the inertial force acting on the mass block and uses Newton’s second law to calculate the acceleration value. Standard accelerometer sensors include inductive, capacitive, strain gauge, piezoresistive, and piezoelectric, according to the various sensitive components of the sensor.
Types of accelerometer sensor
The following are the common types of accelerometer sensors:
1. Piezoelectric Accelerometer Sensor:
A piezoelectric accelerometer operates as a sensor. Users can use the piezoelectric effect sensors to monitor acceleration forces. It comprises a mass fixed to a piezoelectric crystal, which produces an electrical charge when subject to force. Additionally, the mass may deform the crystal if you apply accelerating forces to it. Deformation may result in the production of an electric charge to the acceleration force. Furthermore, the designer can magnify the charge after the sensor produces it and utilize it to measure the acceleration. This accelerometer is appropriate for applications involving high-frequency vibration and shocks, such as seismic measurements, monitoring vehicle and aircraft vibration, and measuring g-forces during athletic competition.
2. Piezoresistive Accelerometer Sensor:
A Piezoresistive Accelerometer Sensor measures the effect of acceleration forces using piezoresistive. It comprises a mass attached to a piezo resistor that changes its electrical resistance when you subject it to force. In addition, applying acceleration forces to the mass causes the piezo resistor to deform, which changes the electrical resistance. Additionally, the change in resistance is proportional to the acceleration force and can help measure the acceleration. Piezoresistive Accelerometer Sensor is ideal for applications requiring low power consumption and noise, such as automotive applications.
3. Capacitive Accelerometer Sensor:
A capacitive accelerometer is a type of sensor that measures linear acceleration. It consists of a semiconductor substrate, typically silicon, with several fixed electrodes on one side and several movable electrodes on the other. The electrodes are in a pattern that when you subject the sensor to linear acceleration, the movable electrodes move relative to the fixed ones. This movement changes capacitance at the electrodes, which, when the designer measures, can help calculate the acceleration. Additionally, the capacitive accelerometer is a susceptible device and can measure acceleration as slightly as a few milligrams. Its sensitivity is typically in the range of 10-1000 milligrams (mg). The capacitive accelerometer is helpful in various applications such as automotive, medical, industrial, and aerospace.
4. Servo Accelerometer Sensor:
Servo accelerometers use a servo mechanism to measure acceleration. The device consists of a proof mass suspended by a spring and moving in response to acceleration. The engineers join the proof mass to a feedback loop that adjusts the voltage one will apply to an electrostatic actuator, which helps keep the proof mass fixed. The voltage essential to maintain the proof mass in a fixed position is proportional to the acceleration the designer is measuring. Servo accelerometers commonly help in aerospace and military applications requiring high accuracy and stability.
Application of accelerometer sensor
Accelerometer sensor is helpful in various areas, such as:
1. Geophone design:
A geophone is a device that detects, measures, and records ground movement. Accelerometers are helpful in geophones to measure ground motion, as they are sensitive to the acceleration of the ground. The designer mounts the accelerometer on the geophone and connects it to a device that converts the acceleration signals into electrical signals easily readable by a computer. Additionally, the accelerometer sensor measures the ground movements in three axes and provides the data to the computer for further analysis. In addition, the accelerometer measures the vibrations which could result from seismic activities, such as earthquakes. With the help of accelerometers, users can create a 3D map of the seismic activity in a detailed area map from data collected from the geophones.
2. Car Accident Alarm:
An accelerometer sensor can help detect sudden changes in acceleration, which can indicate a car accident. The designer positions the accelerometer inside the car and programmes it to detect sudden changes in acceleration, such as a sudden stop or sharp turn. If the accelerometer detects a significant change, it will trigger an alarm, such as a loud siren or flashing lights. This alarm, therefore, alerts the driver of a potential car accident, and the driver can take appropriate action. Additionally, if the manufacturers equip the car with a GPS, the alarm will transmit an alert to emergency services, allowing them to respond quickly in the event of an accident.
3. Monitoring Galloping of High-Voltage Wires:
High-voltage wires can gallop or vibrate due to strong winds and other external forces. Galloping can cause damage to the wires and the surrounding infrastructure if not checked. An accelerometer sensor detects these vibrations, allowing engineers to monitor the galloping of the wires and take appropriate action. Additionally, designers can attach the accelerometer to the wire and program it to detect vibrations above a certain threshold. If the accelerometer sensor detects a vibration, it alerts the engineers, allowing them to rectify the faults.
4. Car safety:
The application of accelerometer sensors in car safety is extensive. Accelerometers measure the rate of change in velocity to detect any sudden acceleration or deceleration, whether due to an impact or a sudden stop. This information helps see a crash and trigger airbags and other safety features. Additionally, accelerometers detect the severity of a collision, which allows for measuring the force exerted on the car and determining the proper deployment of airbags depending on the situation.
5. Compensate the dead angles in GPS Navigation System:
The application of an accelerometer sensor helps compensate for dead angles in GPS navigation systems. Dead angles are areas with blocked or weakened GPS signals, often due to terrain or buildings. Accelerometers measure the vehicle’s acceleration, and the data from the measurement help determine if the car is moving in a straight line or turning. Designers can improve the accuracy of the navigation system by combining this data with the GPS signal.
Accelerometer Sensor Installation
The following is the procedure to follow to install an Accelerometer Sensor successfully:
- Identify the mounting location:
Depending on the application, designers should install an accelerometer at the point of interest, generally the engine, suspension, or chassis of the vehicle. It’s crucial to ensure the mounting location is physically stable, with sufficient clearance, and away from vibration sources.
- Gather the accelerometer and mounting hardware:
Manufacturers should mount the accelerometer sensor securely to the mounting bracket using the provided hardware. Additionally, they should orient the accelerometer sensor to line the axis of interest with the direction of acceleration. Finally, if the designer uses a vibration isolator, they should attach it between the accelerometer and the mounting surface.
- Connect the accelerometer sensor to the power source:
Operators can execute this step by soldering the positive and negative wires of the accelerometer to the power source. Alternatively, users can connect the accelerometer sensor to the power supply using a connection.
- Configure the accelerometer sensor:
Designers can complete the configuration process by linking the accelerometer to a computer using a USB or serial interface. The designer can configure the accelerometer sensor by manually entering the settings or using the offered setup tools.
- Tested accelerometer sensor:
Testing the accelerometer sensor confirms that it is working correctly. Measuring the output of the accelerometer when driving the car in different conditions helps with the testing procedure. Furthermore, the users should compare the outcome of the accelerometer to the projected output of the accelerometer to confirm it is working appropriately.
Methods of mounting Accelerometer Sensor
Below are methods one can apply when mounting an Accelerometer Sensor:
1. Probe:
A probe measures the position or vibration of an object. It comprises a flexible, elongated wire with a contact tip at the end that designers can insert into an opening or hole in the object. The probe measures the vibration or displacement of the thing, providing a signal to calculate the motion.
2. Magnetic base:
A magnetic base is a mounting device that uses a magnetic field to attach an accelerometer sensor to a surface. The base consists of a magnet, a mounting plate, and a mounting bracket. Additionally, the magnet is an electromagnet, and the mounting plate and bracket are from a non-magnetic material such as aluminum or stainless steel. The magnet provides a solid attachment to the surface, allowing the accelerometer to measure the motion in the desired direction.
3. Adhesive Mounting base:
A common way to mount an accelerometer sensor is with an adhesive mounting base. It uses a mounting base, often made of metal, plastic, or a composite material, with an adhesive backing those sticks to the accelerometer’s surface. In some circumstances, the adhesive backing may directly assist the accelerometer. For example, the adhesive backing may be helpful to the mounting base before attaching the mounting base to the accelerometer. Designers advocate using a heat gun or other thermal application equipment since the adhesive backing is pressure sensitive. When a more long-term mounting solution is needed, adhesive mounting bases offer a safe and dependable way to mount the accelerometer.
4. Adhesive wax:
Adhesive wax is a standard method that helps mount an accelerometer sensor. It involves melting a wax material, such as paraffin wax, onto the surface of the accelerometer sensor. After melting the wax material, designers allow it to harden and form a bond between the accelerometer and the mounting surface.
5. Adhesive Cement:
Adhesive cement uses a unique adhesive material to attach the sensor to a mounting surface. Since it creates a solid bond between the accelerometer sensor and the mounting surface, this technique provides a safe and dependable mounting option for the sensor. Moreover, adhesive cement is perfect for applications in automobile or aerospace industries where engineers must firmly and securely fasten the sensor to the mounting surface. The adhesive material applicable in this process includes a two-part epoxy or acrylic adhesive, available in various colors, viscosities, and curing times.
6. Isolated Mounting Stud:
An isolated mounting stud helps in an accelerometer sensor mounting approach, which isolates the mounting stud from the mounting surface. Isolated Mounting stud does not require sticky materials or other mounting techniques that could compromise the accelerometer sensor’s operation, making it a safe and reliable installation choice. Moreover, an isolated mounting stud is ideal for uses where the sensor needs a firm connection to the mounting surface without interference from other objects or materials. The mounting stud consists of sturdy material, such as aluminum or stainless steel, to resist corrosion and wear.
7. Mounting stud:
This method involves attaching the accelerometer sensor to a rigid surface through a mounting stud. The mounting stud comprises stainless steel, which securely holds the accelerometer in place. The mounting stud works by screwing the stud into a tapped hole in the mounting surface. When mounting an accelerometer sensor using a mounting stud, it is essential to ensure that you properly secure the stud and that the mounting surface is clean and free of contaminants. Additionally, it is crucial to ensure that the mounting stud is of the correct size for the accelerometer sensor. If the stud is too small, the accelerometer sensor may shift or become loose during vibration or shock, leading to inaccurate readings.
Benefits of accelerometer sensor
- Simple to interface and rugged in design:
Accelerometers are relatively simple to interface with other systems, making them easily integrated into various applications. Additionally, their design makes them easy to rug, therefore suitable for harsh environments.
- High impedance:
Accelerometers have high input impedance; thus, they do not draw a lot of current from the connected system. This feature makes them ideal for use in low-power systems.
- Higher sensitivity:
Modern accelerometers are highly sensitive, hence, able to detect tiny changes in acceleration. This aspect makes them ideal for applications that require precise measurements.
- High-frequency response:
Accelerometers have a high-frequency response, enabling them to detect changes in acceleration at high frequencies. This feature makes them ideal for applications that involve high-speed motion or vibration.
- Available at a lower cost due to advancements in MEMS technology:
Micro-electromechanical systems (MEMS) technology advancements have led to the development of small, low-cost accelerometers widely available in the market. This has made them accessible to a wide range of applications that require motion sensing.
- Built-in signal conditioning circuit to measure capacitance:
Some accelerometers have a built-in signal conditioning circuit that allows them to measure capacitance. This makes them more accurate and reliable in measuring acceleration.
Conclusion
In conclusion, accelerometer sensors are incredibly versatile and helpful in various sectors. From monitoring the galloping of high-voltage wires and car accident alarms to compensating for dead angles in GPS navigation systems, accelerometer sensors provide an invaluable tool to designers and engineers. Furthermore, with the proper installation technique, accelerometer sensors can be reliable and accurate. So, if you need a device to measure acceleration, don’t hesitate to try your trusty accelerometer – you won’t regret it!
