Angular Acceleration Sensor Research Articles

Study of the Mechanism of Perceived Rotational Acceleration of a Bionic Semicircular Canal on the Basis of the "Circular Geometry Hypothesis".

Academia often uses the "circular geometry hypothesis" to explain the sensing principle of the human semicircular canal (SCC) system for angular acceleration, which is widely accepted as an important angular acceleration sensor in the human balance system. On the basis of this hypothesis and the anatomical structure of human SCCs, a series of physical SCC models with different geometries at 4× magnification were prepared via three-dimensional printing and modification of hydrogels. Theoretical models of the SCC perception mechanism were established. Then, impulse angular acceleration, sinusoidal rotation, and sinusoidal linear stimulation were applied to the models, and their responses were visually observed and analyzed in detail. As a result, the circular SCC model had a larger system gain and a smaller phase difference for angular acceleration stimulation but a smaller system gain and a larger phase difference for linear acceleration stimulation. These results verified that the circular semicircular canal was more sensitive to angular acceleration. Our bionic model is hoped to be used for demonstrating the human SCC working process, facilitating researchers in better understanding of the working mechanism of the human SCC, or as a manual model for medical staff to simulate the diagnosis and treatment of human SCC.

Investigation of FBG Linear/Angular Acceleration Sensor for Novel Type Inertial Measurement

A novel inertial measurement unit (IMU) was proposed to measure the three-axis linear/angular acceleration of a body using six fiber Bragg grating (FBG) optical fiber acceleration sensors sharing the same rotational center. The six acceleration sensors were shown to accurately distinguish between movements in different directions using a vibration generator and rotary motor/encoder device. The results also indicated that the measurement range of the FBG linear acceleration sensor was ±14 g, its average sensitivity was approximately 229.4 pm/g, and its nonlinearity was under 0.05%. Furthermore, the average sensitivity and nonlinearity of the FBG angular acceleration sensor were 21°/s²/pm and 0.23%, respectively. When measuring linear and angular acceleration, the cross-axis sensitivity of the IMU was within 2.0%. The measurement accuracy of the roll and pitch angle during 360° rotation as well as that of the yaw angle during 720° rotation were both in the range of 0.54 to 1.31%. Most of results indicated that the FBG-based IMU sensor was within the performance specifications of an equivalent conventional IMU sensor. Thus, the concept underlying the proposed sensor can be confidently used as a basis to develop a high-precision IMU sensor that is unaffected by electromagnetic interference.

Algorithms for Complexing an Inertial Navigation System with Angular Acceleration Sensors

In this paper the problem of increasing the accuracy of inertial navigation system of an aircraft in the absence of high-precision additional information sensors, such as GPS, has been studied. It is proposed to install angular acceleration sensors on the gyrostabilized platform of the inertial navigation system. The use of signals from the angular acceleration sensors made it possible to generate correction signals for the inertial navigation system. Correction algorithms have been developed in the structure of the inertial navigation system and in its output signal. The effectiveness of the developed algorithms has been demonstrated using semi-natural simulation with the Ts060K inertial navigation system.

Dynamic response of a coal rock caving impact tail beam for hydraulic support

Based on the two-way coupling technology of Discrete Element Method-Multi Flexible Body Dynamics (EDM-FMBD), a virtual caving coal wall is established by using the discrete element software, EDEM. The rigid flexible coupling model of the tail beam of caving supports is established by using multibody dynamics software, RecurDyn. The stiffness of the oil cylinder is calculated by using the solid–liquid spring coupling theory and is replaced by a spring. By simulating the process of a coal rock collapse impacting the tail beam, the dynamic signal from the coal rock collapse impacting the tail beam to crushing in the coal caving stage of the comprehensive caving working face is studied, and the test is carried out underground. The angular acceleration at the hinge point of the tail beam is the largest and shows a variation pattern of "large at both ends and small in the middle". The definition of a "low amplitude band" on the surface of the tail beam is proposed. The force signal at the hinge point of the front link is the strongest and is the best measurement point for the force sensor; the angular acceleration signal at the hinge point of the tail beam is the strongest and it is the best measurement point for the angular acceleration sensor. The results have practical implications for the identification of the coal gangue and the adaptive control of support for integrated top coal mining.

Biaxial Angular Acceleration Sensor with Rotational-Symmetric Spiral Channels and MEMS Piezoresistive Cantilevers.

Angular acceleration sensors are attracting attention as sensors for monitoring rotational vibration. Many angular acceleration sensors have been developed; however, multiaxis measurement is still in a challenging stage. In this study, we propose a biaxial angular acceleration sensor with two uniaxial sensor units arranged orthogonally. The sensor units consist of two rotational-symmetric spiral channels and microelectromechanical system (MEMS) piezoresistive cantilevers. The cantilever is placed to interrupt the flow at the junctions of parallelly aligned spirals in each channel. When two cantilevers are used as the resistance of the bridge circuit in the two-gauge method, the rotational-symmetric spiral channels enhance the sensitivity in the target axis, while the nontarget axis sensitivities are canceled. The fabricated device responds with approximately constant sensitivity from 1 to 15 Hz, with a value of 3.86 × 10−5/(rad/s2), which is equal to the theoretical value. The nontarget axis sensitivity is approximately 1/400 of the target axis sensitivity. In addition, we demonstrate that each unit responds according to the tilt angle when the device is tilted along the two corresponding rotational axis planes. Thus, it is concluded that the developed device realizes biaxial angular acceleration measurement with low crosstalk.

Stratification of hippocampal electrophysiological activation evoked by selective electrical stimulation of different angular and linear acceleration sensors in the rat peripheral vestibular system

It has become well established that vestibular information is important for hippocampal function and spatial memory. However, as yet, relatively little is known about how different kinds of vestibular information are ‘represented’ in different parts of the hippocampus. This study used selective electrical stimulation of each of the 5 vestibular sensors (the horizontal (HC), anterior (AC) and posterior (PC) semi-circular canals, and the utricle and saccule) in the rat and recorded local field potentials (LFPs) across the hippocampus, using a 16 electrode microarray. We found that stimulation of any vestibular sensor in the left labyrinth evoked triphasic LFPs in both hippocampi, although it was clear that, in general, the amplitudes were greater for the right, contralateral side. This was particularly true for Phase 1 for the HC, AC, utricle and saccule, Phase 2 for the HC, PC, utricle and saccule, and Phase 3 for the AC, PC and saccule. Overall, our results suggest that vestibular input to the hippocampus is bilateral, preferentially contralateral, but highly stratified in that stimulation of the same vestibular sensor results in activation of different specific areas of the hippocampus, with different LFP amplitudes and latencies. This suggests the possibility that different regions of the hippocampus use different kinds of vestibular information for different purposes and that there may be a high degree of redundancy in the representation of vestibular input, perhaps ensuring that the hippocampus is more robust to the partial loss of vestibular information.

Biaxial angular acceleration sensor using inertial force in the spiral channels and MEMS differential pressure sensors

Biaxial angular acceleration sensor using inertial force in the spiral channels and MEMS differential pressure sensors

Universal Piezoelectric Seismometer

A universal piezoelectric seismometer is proposed that can simultaneously record linear and angular accelerations through two separate channels. The operational principle of the seismometer and the features of its design are described; the mechanical and electric circuits are considered. The device uses two-element piezoelectric linear and angular acceleration sensors with a total inertial mass. The principle of addition and compensation of electric signals is implemented. The channel sensitivities are referenced to real seismic vibration values. Based on an analysis of a large number of seismic vibration records, seismometer parameters are proposed that are suitable for use in the near fields of strong earthquakes.

A simplified modelling and analysis of six degree of freedom random vibration test

This paper deals with the modelling and analysis of six degree of freedom random vibration test. It involves an advanced multi-input multi-output random vibration test system where three translational and three rotational motions can be controlled simultaneously. In this work, a mechanical model of the six degree of freedom vibration test system is established such that eight exciters are modelled as spring damper pairs and the shaker table is assumed to be rigid. The acceleration properties of the test article undergoing such six degree of freedom base vibrations are analyzed and the relationships among the absolute acceleration, relative acceleration and base acceleration are derived. In practical applications, typically there is no available angular acceleration sensor for high frequency measurements. Therefore, the three rotational accelerations are obtained from measured translational accelerations of three or more control sensors with a response coordinate transformation matrix. It is shown that the locations of the control points have a significant influence on the response spectral results, which is reflected in the condition number of the output coordinate transformation matrix. The general multi-input multi-output random vibration control method is applied to the 6-DOF random vibration test. A six degree of freedom random vibration test simulation is finally provided.

Angular accelerometer‐based inertial navigation system

Angular acceleration sensors technologies are evolving and emerging in various applications. In this paper, we propose an angular accelerometer-based inertial navigation system. One application of such systems can be highly maneuvering platforms where direct measurement of angular acceleration is desired. To that end, a review of modern angular acceleration sensor technologies and their possible applications is provided. Two angular acceleration-based inertial navigation system architectures are suggested, and their equations of motion are derived. Additionally, an analytical assessment for short time periods of pure inertial navigation is provided with a comparison to traditional and gyro-free inertial navigation architectures.

Improving the efficiency of the search methods of the refused sensor in an excessive angular speed meters

In control systems of launch vehicles, satellites, it is important to ensure the operability of the system in the presence of failures. In the units of angular velocity or acceleration sensors, redundancy can be used, that is, the installation of sensors in the amount of four to six, the sensitivity axis of any three of them are not coplanar. In addition to reliability improvement the redundant meters improve the accuracy characteristics of systems. To determine the failed sensors, special algorithms which influence the efficiency of the failed sensor search have been developed. The following search methods are considered: the method of the failed sensor determining by the minimum of average values of the residual modules; method for the failed sensor determining by the minimum of mean values of squared residuals method for the failed sensor determining by the minimum of the squares deviations average values of the angular velocity components; method for the failed determining sensor by the maximum modulus of the difference of the calculated and measured data. The probabilities of determining failures, false failures, and undetected failures are given. The methods of finding a failed sensor in the redundant angular velocity meters given in the article take into account the presence of errors in the transmittance of sensors.

Highly sensitive and low-crosstalk angular acceleration sensor using mirror-symmetric liquid ring channels and MEMS piezoresistive cantilevers

This paper describes an angular acceleration sensor that uses liquid ring channels and piezoresistive cantilevers. The detection of fluidic rotation has attracted attention as a sensing principle for angular acceleration due to the simple structure and potentially low power consumption of devices that use said principle. Although the existing angular acceleration sensors that use this sensing principle have the potential for high sensitivity to angular acceleration about the target axis, crosstalk is an issue—specifically, crosstalk with angular accelerations about other axes and with linear acceleration. Here, we propose an angular acceleration sensor that uses a MEMS piezoresistive cantilever as the sensing element and two mirror-symmetric ring channels. This mirror symmetry cancels out the signals due to accelerations about the other axes, while the signal for the angular acceleration about the target axis is doubled. The experimental results show that the sensitivity to other axial angular accelerations and linear acceleration is sufficiently small. The obtained sensitivity for the angular acceleration is as high as 3.1 × 10−4 (rad/s2)-1, similar to theoretical predictions. This value for the sensitivity is maintained over a range of frequencies from 0.1 Hz to 100 Hz. Therefore, the proposed sensor is suitable for practical angular acceleration detection applications.

Wireless acceleration sensor of moving elements for condition monitoring of mechanisms

Comprehensive analysis of the angular and linear accelerations of moving elements (shafts, gears) allows an increase in the quality of the condition monitoring of mechanisms. However, existing tools and methods measure either linear or angular acceleration with postprocessing. This paper suggests a new construction design of an angular acceleration sensor for moving elements. The sensor is mounted on a moving element and, among other things, the data transfer and electric power supply are carried out wirelessly. In addition, the authors introduce a method for processing the received information which makes it possible to divide the measured acceleration into the angular and linear components. The design has been validated by the results of laboratory tests of an experimental model of the sensor. The study has shown that this method provides a definite separation of the measured acceleration into linear and angular components, even in noise. This research contributes an advance in the range of methods and tools for condition monitoring of mechanisms.

A micromachined angular-acceleration sensor for geophysical applications

This paper presents an angular-acceleration sensor that works as either an angular accelerometer or a gravity gradiometer and is based on the micro electromechanical system (MEMS) technology. The changes in the angle of the sensor mass are sensed by a rotational capacitive array transducer that is formed by electrodes on both the stator and rotor dies of the flip-chip-bonded MEMS chip (21 mm × 12.5 mm × 1 mm). The prototype was characterized, demonstrating a fundamental frequency of 27 Hz, a quality factor of 230 in air, and a sensitivity of 6 mV/(rad/s2). The demonstrated noise floor was less than 0.003 rad/s2/Hz within a bandwidth of 0.1 Hz to 10 Hz, which is comparable with the conventional angular accelerometer and is better than the other reported MEMS sensors in low-frequency ranges. The features of small size and low cost suggest that this MEMS angular-acceleration sensor could be mounted on a drone, a satellite or even a Mars rover, and it is promising to be used for monitoring angular accelerations, aiding seismic recording, mapping gravity anomalies, and other geophysical applications for large-scale terrestrial and space deployments.

Study on a Ship with 6 Degrees of Freedom Inertial Measurement System and Related Technologies

We research ship 6 DOF inertial measurement method and displacement reconstruction form acceleration signal to establish the strap-down inertial navigation measurement system through sensors configuration technology. The inertial measurement system consists of three groups of vertically mounted angular rate and acceleration sensors. Through designing an FIR integration filter and studying the ship displacement signal reconstruction from the acceleration, the filter parameters design method and implementation way were determined. By means of the beam vibration to analog ship heave motion reconstructs linear displacement form acceleration signals. The root mean square error of the reconstructed line displacement is 0.004 mm, and the mean value of the displacement peak value is 5.92%, which is close to the design precision of the filter. The test shows that the measurement system and the FIR filter to achieve the predetermined precision with noise suppression.

A Novel Permanent Magnetic Angular Acceleration Sensor.

Angular acceleration is an important parameter for status monitoring and fault diagnosis of rotary machinery. Therefore, we developed a novel permanent magnetic angular acceleration sensor, which is without rotation angle limitations and could directly measure the instantaneous angular acceleration of the rotating system. The sensor rotor only needs to be coaxially connected with the rotating system, which enables convenient sensor installation. For the cup structure of the sensor rotor, it has a relatively small rotational inertia. Due to the unique mechanical structure of the sensor, the output signal of the sensor can be directed without a slip ring, which avoids signal weakening effect. In this paper, the operating principle of the sensor is described, and simulated using finite element method. The sensitivity of the sensor is calibrated by torsional pendulum and angle sensor, yielding an experimental result of about 0.88 mV/(rad·s−2). Finally, the angular acceleration of the actual rotating system has been tested, using both a single-phase asynchronous motor and a step motor. Experimental result confirms the operating principle of the sensor and indicates that the sensor has good practicability.

An Innovative and Reliable Wireless Angular Accelerometer Made Directly on a Flexible Substrate without Moving Parts

Five novel ideas are proposed in this paper to integrate an active RFID tag with a thermal convection angular accelerometer on a flexible substrate, thus the new device becomes a wireless sensor. The first innovative idea is that this device is without any movable parts, so it is very reliable. The second new idea is that it is made on a flexible substrate, such as plastic or polyimide, the thermal conductivity of the flexible substrate is much lower than silicon, and thus it can save more power and very useful for mobile operation. The third new idea is to apply xenon gas in the chamber to conduct the heat instead of the traditional carbon dioxide, so no oxidation and performance degradation effects will be produced on the heater and thermal sensors. The fourth new idea is to integrate with an active RFID tag on the same substrate, thus the device becomes a more useful wireless angular acceleration sensor. The final new idea is to apply a hemispherical chamber instead of the conventional rectangular one. From the simulation results one can see it is a good idea to apply a non-floating type angular accelerometer with a hemispherical chamber, the sensitivity performance is the best (395K/(rad/sec2)), and the response speed (693μs) is also comparable to the traditional one by using a floating type with a rectangular chamber (593μs). In summary, from the considerations of reliability, cost and performance, the non-floating type angular accelerometer with hemispherical chamber is a better choice.

Vehicle Speed Estimation in Driving Mode for Hybrid Electric Car Using Unscented Kalman Filter

As for the four-wheel drive hybrid electric car with complex and changeable driving modes, unscented Kalman filter(UKF) is proposed for vehicle speed estimation in consideration of obtainable driving torque and electronic stability program(ESP) senor signals. Simulation platform is established according to the four-wheel drive hybrid electric car, which integrates power-train system model, nonlinear seven degree of freedom vehicle dynamics model and the dynamic union tire model. The estimation result of UKF algorithm is compared with the simulated real car's velocity. After steering wheel angle sensor, yaw angular velocity sensor and acceleration sensors are all mounted in the prototype car and the signals of two front wheel angular speed are acquired as well as the torque information of driving wheel are introduced, UKF algorithm is tested on the real vehicle road experiments, which include 8-shape route driving case on pure electric drive mode, double-lane change driving case and S-shape route driving case on four wheel hybrid drive mode. Simulation and test results show that the proposed algorithm has not only high precision, but also strong adaptability.

Robust online roll dynamics identification of a vehicle using sliding mode concepts

This paper proposes a robust observer concept for joint estimation of system states and model parameters related to the roll dynamics of a vehicle. Using sliding mode concepts introduces robustness to parametric uncertainties and also allows reconstruction of the latter. These model parameters are of interest for vehicle dynamics assessment and estimation of the roll angle. A novel classification concept exploits these parameter estimates for assessing the roll dynamics. An additional benefit of the proposed method is the minimal requirement of measurement equipment as it only relies on cost-efficient angular rate and acceleration sensors. Evaluation of the framework is performed in simulations and real-world using an experimental vehicle.

Angular Acceleration Measurement Experiment Study of Stepping Motor on Single Clap Operation

Apparent rotational angular acceleration exist in the stepper motor operation processing, the stepper motor torque angle characteristics were described and the mathematical model of motor are constructed; The actual angular acceleration of stepper motor on single-step operation is measured by self-developed rotating angular acceleration sensor, the experimental results show that the angular acceleration fluctuations of stepping motor on three single clap operation are little greater than on six clap operation, and there are return oscillations of motor on three single clap operation are obviously more than on six clap operation; Finally, the experimental phenomenon reasons are analyzed, and the corresponding conclusions are obtained.