Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental...Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental mechanics theories, a kind of 1-3 orthogonalanisotropic PCM (OAPCM) sensor is developed, and the sensing principle is analyzed to describesensor behaviors. In order to determine strain and stress on isotropic or orthogonal anisotropiccomponent surface, the relationships between strain and stress are established. The experimentalresearch on 1-3 OAPCM sensor is carried out in uniaxial and biaxial stress states. The results showthat 1-3 OAPCM sensors offer orthotropic properties of piezoelectricity, and sensing equations canbe used for strain or stress measurement with good accuracy.展开更多
To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into i...To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter.展开更多
This paper presents a new designed miniature six DOF (degree of freedom) force/torque sensor. This sensor is fully integrated with a micro DSP (digital signal processor), so all the signal conditioning, A/D, decou...This paper presents a new designed miniature six DOF (degree of freedom) force/torque sensor. This sensor is fully integrated with a micro DSP (digital signal processor), so all the signal conditioning, A/D, decoupling, digital-signals serial output are performed in the sensor. Some experimental results are presented to demonstrate the capability of the proposed design. Finally, a neural network was used for decoupling the interacting signals, compared with the conventional method using the inverse matrix, this new method is more accurate.展开更多
The software system, hardware system and performance principle of the gas detector were briefly described. A new method was developed for orientating and cali- brating the instrument. The method shows excellence in au...The software system, hardware system and performance principle of the gas detector were briefly described. A new method was developed for orientating and cali- brating the instrument. The method shows excellence in automation and intelligence, and presents simpler and more reliable new method for orientating and calibrating the nominal physical quantity of the nonlinear sensor.展开更多
An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio ...An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio to genetic algorithm, and the optimization parameters of genetic algorithm were given. The relevant experimental system is constructed. The simulation and experiments show that the analytical method proposed can be applied to analyze the reflective spectra of the quasistatic FBG sensing system at transverse uniform press, the strain measurement with high-precision of 0.91% can be realized展开更多
A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is proposed.First,a three-layer fundamental archi...A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is proposed.First,a three-layer fundamental architecture is proposed to overcome the inherent distributed management and rigidity of the conventional wireless sensor networks.Furthermore,the platform for research and development of MA-SDSN is established,and the dumb node(DN),the software-defined node(SN)and the movement-assisted node(MN)are designed and implemented.Then,the southbound application programming interface(API)is designed to provide a series of frames for communication between controllers and sensor nodes.The northbound API is developed and demonstrated overall and in detail.The functions of the controller are presented including topology discovery,dynamic networking,packet processing,mobility management and virtualization.Followed by the MA-SDSN network model,a Markov chain-based movement-assisted weighted relocation(MMWR)topology control algorithm is proposed to redeploy the MNs based on the node status and weight.Simulation results and analysis indicate that the proposed algorithm based on the MA-SDSN extends network lifetime with a lower average power consumption.展开更多
An improved encapsulation method of a sensing element for a cement-based piezoelectric sensor used in civil engineering structure was developed and some tests were carried out for validating this method. The cement-ba...An improved encapsulation method of a sensing element for a cement-based piezoelectric sensor used in civil engineering structure was developed and some tests were carried out for validating this method. The cement-based piezoelectric sensor of this kind is mainly used in concrete structure due to its compatibility with concrete, and the encapsulation method of its sensing element is important to the effectiveness and accuracy of the transfer of the stress from concrete to the sensing element. The sensor′s measurement error of the previous encapsulation method, which was induced by the area of the encapsulation material and the inherent difference of Young′s modulus between cement and encapsulation material, was analyzed theoretically using parallel model. In the improved method, the error is minimized by decreasing the area of the encapsulation material and changing the configuration of the cement and piezoelectric material in the sensor. Two sensors made by the previous and improved methods were embedded in two prisms respectively and the prisms were compressed on Material Test System. Through the comparison of the measurement errors of the two sensors, the improved method was evaluated. The test results show that the improved encapsulation method is effective and feasible.展开更多
A carbon nanotube-based(CNT) sensing element is presented, which consists of substrate, insulating layer, electrodes, carbon nanotube and measuring circuit. The sensing components are a single or array of CNTs, which ...A carbon nanotube-based(CNT) sensing element is presented, which consists of substrate, insulating layer, electrodes, carbon nanotube and measuring circuit. The sensing components are a single or array of CNTs, which are located on the two electrodes. The CNT-based sensing element is fabricated by CVD (chemical vapor deposition)-direct-growth on micro- electrodes. The sensing model and measurement method of electromechanical property are also presented. Finally, the voltage-current characteristics are measured, which show that the CNT-based sensing element has good electrical properties.展开更多
For the modified demodulation arithmetic of 3×3 coupler, the processing software built on the basis of Labview is able to demodulate asymmetric 3×3 coupler signal and do further spectrum analysis. It shows t...For the modified demodulation arithmetic of 3×3 coupler, the processing software built on the basis of Labview is able to demodulate asymmetric 3×3 coupler signal and do further spectrum analysis. It shows that the measured frequency ranges from 10 Hz to 1 000 Hz and phase range is covered by -10 rad^10 rad. The phase sensitivity is 0.5 V/rad. This system is proved to show high resolution and wide dynamic range.展开更多
A new kind of hydraulic transformer, called variable hydraulic transformer(VHT), is proposed to control its load flow rate. The hydraulic transformer evolves from a pressure transducer to a power transducer. The flow ...A new kind of hydraulic transformer, called variable hydraulic transformer(VHT), is proposed to control its load flow rate. The hydraulic transformer evolves from a pressure transducer to a power transducer. The flow characteristics of VHT, such as its instantaneous flow rates, average flow rates, and flow pulsations in the ports, are investigated. Matlab software is used to simulate and calculate. There are five controlled angles of the port plate that can help to define the flow characteristics of VHT. The relationships between the flow characteristics and the structure in VHT are shown. Also, the plus-minus change of the average flow rates and the continuity of the instantaneous flow rates in the ports are presented. The results demonstrate the performance laws of VHT when the controlled angles of the port plate and of the swash plate change. The results also reveal that the special principle of the flow pulsation in the ports and the jump points of the instantaneous curves are the two basic causes of its loud noise, and that the control angles of the port plate and the swash plate and the pressures in the ports are the three key factors of the noise.展开更多
Magnetism parameters vary with the position and the speed of electromagnetic actuator's motion parts.The measurement unit presented in the paper can be applied to get the position and the speed feedback informatio...Magnetism parameters vary with the position and the speed of electromagnetic actuator's motion parts.The measurement unit presented in the paper can be applied to get the position and the speed feedback information from the measurement of electromagnetism parameters,and can constitute the untouched feedback sensing unit in the closed-loop motion control,and it adapts to the diversified feedback control of electromagnetic actuator.The digital miniaturization meter,based on MSP430 single chip processor,which can do the multi-purpose measurement of Φ & B through the menu selection,can be used for the electromagnetic actuator's performance evaluation and improvement,and also the online quality control in production process.Both real-time data graph and data table can be displayed in the meter.The paper presents the system's structure,describes the principle,discusses the working modes,and shows the software flowchart and the measuring results.展开更多
Recently, the Internet of Things (loT) has attracted more and more attention. Multimedia sensor network plays an important role in the IoT, and audio event detection in the multimedia sensor net- works is one of the...Recently, the Internet of Things (loT) has attracted more and more attention. Multimedia sensor network plays an important role in the IoT, and audio event detection in the multimedia sensor net- works is one of the most important applications for the Internet of Things. In practice, it is hard to get enough real-world samples to generate the classifi- ers for some special audio events (e.g., car-crash- ing in the smart traffic system). In this paper, we introduce a TrAdaBoost-based method to solve the above problem. By using the proposed approach, we can train a strong classifier by using only a tiny amount of real-world data and a large number of more easily collected samples (e.g., collected from TV programs), even when the real-world data is not sufficient to train a model alone. We deploy this ap- proach in a smart traffic system to evaluate its per- formance, and the experiment evaluations demonstrate that our method can achieve satisfying results.展开更多
Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance Ⅰ of broken en...Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance Ⅰ of broken ends and output volt Ⅴ, when Ⅰ ≥60 mm, Ⅴ keeps constantly, the running speed v of wire-core belt has no big effect on output volt Ⅴ, there is inverse proportion between the height h from probe to the surface of the belt and output volt Ⅴ, when h≥30 mm, Ⅴ tends to be zero. Based on the test result, on-line monitoring installation is developed, the practice proved that the accuracy of broken wire monitoring can be above 95%, the monitoring accuracy of joint twitch can be 0 .04 Ⅴ/mm.展开更多
In this paper,the sensors array technique is applied to the quality detection of aluminum alloy spot welding.The sensors array has three forms,i.e.,linear magnetic sensors array,annular magnetic sensors array and cros...In this paper,the sensors array technique is applied to the quality detection of aluminum alloy spot welding.The sensors array has three forms,i.e.,linear magnetic sensors array,annular magnetic sensors array and cross magnetic sensors array.An algorithm based on principal component analysis is proposed to extract the signal eigenvalues.The three types of magnetic sensors array are used in the experiment of monitoring the signal.After the eigenvalues are extracted,they are used to build a relationship with ...展开更多
A robot slide tactile sensor based on photoelectric devices is introduced.The sensor is mounted on the hydraulic manipulator and used in a soft grasp control system.The experimental results are also presented.
Cameras can reliably detect human motions in a normal environment, but they are usually affected by sudden illumination changes and complex conditions, which are the major obstacles to the reliability and robustness o...Cameras can reliably detect human motions in a normal environment, but they are usually affected by sudden illumination changes and complex conditions, which are the major obstacles to the reliability and robustness of the system. To solve this problem, a novel integration method was proposed to combine hi-static ultra-wideband radar and cameras. In this recognition system, two cameras are used to localize the object's region, regions while a radar is used to obtain its 3D motion models on a mobile robot. The recognition results can be matched in the 3D motion library in order to recognize its motions. To confirm the effectiveness of the proposed method, the experimental results of recognition using vision sensors and those of recognition using the integration method were compared in different environments. Higher correct-recognition rate is achieved in the experiment.展开更多
The mositure content inside the hermetic package of semiconductor device has been quantitatively measured by using in-site sensor technique and computer-aided-test system.The principle and apparatus for measurement ar...The mositure content inside the hermetic package of semiconductor device has been quantitatively measured by using in-site sensor technique and computer-aided-test system.The principle and apparatus for measurement are introduced.The results show good repeatability and consistency.This technology can be used as a standard test for controlling the moisture content within semiconductor device package.展开更多
A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It...A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2 μm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter.展开更多
文摘Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental mechanics theories, a kind of 1-3 orthogonalanisotropic PCM (OAPCM) sensor is developed, and the sensing principle is analyzed to describesensor behaviors. In order to determine strain and stress on isotropic or orthogonal anisotropiccomponent surface, the relationships between strain and stress are established. The experimentalresearch on 1-3 OAPCM sensor is carried out in uniaxial and biaxial stress states. The results showthat 1-3 OAPCM sensors offer orthotropic properties of piezoelectricity, and sensing equations canbe used for strain or stress measurement with good accuracy.
基金Project(200801346) supported by the China Postdoctoral Science FoundationProject(2008RS4022) supported by the Hunan Postdoctoral Scientific ProgramProject(2008) supported by the Postdoctoral Science Foundation of Central South University
文摘To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter.
基金Supported by the National Natural Science Foundation of China ( No. 60275032 ) and the Supported bv the High Technology Research and Development Programme of China ( No. 2003AA404220).
文摘This paper presents a new designed miniature six DOF (degree of freedom) force/torque sensor. This sensor is fully integrated with a micro DSP (digital signal processor), so all the signal conditioning, A/D, decoupling, digital-signals serial output are performed in the sensor. Some experimental results are presented to demonstrate the capability of the proposed design. Finally, a neural network was used for decoupling the interacting signals, compared with the conventional method using the inverse matrix, this new method is more accurate.
基金Key Project Sponsored by Science and Technology Office of Hebei(01220140D)
文摘The software system, hardware system and performance principle of the gas detector were briefly described. A new method was developed for orientating and cali- brating the instrument. The method shows excellence in automation and intelligence, and presents simpler and more reliable new method for orientating and calibrating the nominal physical quantity of the nonlinear sensor.
文摘An analytical method in a quasi-static fiber grating sensing system under transverse uniform press is proposed based on genetic algorithm The effect of population size, generations, crossover ratio and mutation ratio to genetic algorithm, and the optimization parameters of genetic algorithm were given. The relevant experimental system is constructed. The simulation and experiments show that the analytical method proposed can be applied to analyze the reflective spectra of the quasistatic FBG sensing system at transverse uniform press, the strain measurement with high-precision of 0.91% can be realized
基金The National Natural Science Foundations of China(No.61471164,61601122)
文摘A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is proposed.First,a three-layer fundamental architecture is proposed to overcome the inherent distributed management and rigidity of the conventional wireless sensor networks.Furthermore,the platform for research and development of MA-SDSN is established,and the dumb node(DN),the software-defined node(SN)and the movement-assisted node(MN)are designed and implemented.Then,the southbound application programming interface(API)is designed to provide a series of frames for communication between controllers and sensor nodes.The northbound API is developed and demonstrated overall and in detail.The functions of the controller are presented including topology discovery,dynamic networking,packet processing,mobility management and virtualization.Followed by the MA-SDSN network model,a Markov chain-based movement-assisted weighted relocation(MMWR)topology control algorithm is proposed to redeploy the MNs based on the node status and weight.Simulation results and analysis indicate that the proposed algorithm based on the MA-SDSN extends network lifetime with a lower average power consumption.
基金Supported by Hong Kong Research Grant Council to HKUSTunder grant HKUST6212/O2ENational Science Fund forDistinguished Young Scholars of China(No.50425824).
文摘An improved encapsulation method of a sensing element for a cement-based piezoelectric sensor used in civil engineering structure was developed and some tests were carried out for validating this method. The cement-based piezoelectric sensor of this kind is mainly used in concrete structure due to its compatibility with concrete, and the encapsulation method of its sensing element is important to the effectiveness and accuracy of the transfer of the stress from concrete to the sensing element. The sensor′s measurement error of the previous encapsulation method, which was induced by the area of the encapsulation material and the inherent difference of Young′s modulus between cement and encapsulation material, was analyzed theoretically using parallel model. In the improved method, the error is minimized by decreasing the area of the encapsulation material and changing the configuration of the cement and piezoelectric material in the sensor. Two sensors made by the previous and improved methods were embedded in two prisms respectively and the prisms were compressed on Material Test System. Through the comparison of the measurement errors of the two sensors, the improved method was evaluated. The test results show that the improved encapsulation method is effective and feasible.
基金This work is partially granted by National Natural Science Foun-dation of China (No.50505018)Specialized Research Fund forthe Doctoral Program of Higher Education (No. 20030003024)China Postdoctoral Science Foundation Grant (No.2005038068).
文摘A carbon nanotube-based(CNT) sensing element is presented, which consists of substrate, insulating layer, electrodes, carbon nanotube and measuring circuit. The sensing components are a single or array of CNTs, which are located on the two electrodes. The CNT-based sensing element is fabricated by CVD (chemical vapor deposition)-direct-growth on micro- electrodes. The sensing model and measurement method of electromechanical property are also presented. Finally, the voltage-current characteristics are measured, which show that the CNT-based sensing element has good electrical properties.
文摘For the modified demodulation arithmetic of 3×3 coupler, the processing software built on the basis of Labview is able to demodulate asymmetric 3×3 coupler signal and do further spectrum analysis. It shows that the measured frequency ranges from 10 Hz to 1 000 Hz and phase range is covered by -10 rad^10 rad. The phase sensitivity is 0.5 V/rad. This system is proved to show high resolution and wide dynamic range.
基金Projects(50875054,51275123)supported by the National Natural Science Foundation of ChinaProject(GZKF-2008003)supported by the Open Foundation of State Key Laboratory of Fluid Transmission and Control,China
文摘A new kind of hydraulic transformer, called variable hydraulic transformer(VHT), is proposed to control its load flow rate. The hydraulic transformer evolves from a pressure transducer to a power transducer. The flow characteristics of VHT, such as its instantaneous flow rates, average flow rates, and flow pulsations in the ports, are investigated. Matlab software is used to simulate and calculate. There are five controlled angles of the port plate that can help to define the flow characteristics of VHT. The relationships between the flow characteristics and the structure in VHT are shown. Also, the plus-minus change of the average flow rates and the continuity of the instantaneous flow rates in the ports are presented. The results demonstrate the performance laws of VHT when the controlled angles of the port plate and of the swash plate change. The results also reveal that the special principle of the flow pulsation in the ports and the jump points of the instantaneous curves are the two basic causes of its loud noise, and that the control angles of the port plate and the swash plate and the pressures in the ports are the three key factors of the noise.
基金Sponsored by the Multidiscipline Scientific Research Foundation of Harbin Institute of Technology(Grant No.HIT.MD2002.13).
文摘Magnetism parameters vary with the position and the speed of electromagnetic actuator's motion parts.The measurement unit presented in the paper can be applied to get the position and the speed feedback information from the measurement of electromagnetism parameters,and can constitute the untouched feedback sensing unit in the closed-loop motion control,and it adapts to the diversified feedback control of electromagnetic actuator.The digital miniaturization meter,based on MSP430 single chip processor,which can do the multi-purpose measurement of Φ & B through the menu selection,can be used for the electromagnetic actuator's performance evaluation and improvement,and also the online quality control in production process.Both real-time data graph and data table can be displayed in the meter.The paper presents the system's structure,describes the principle,discusses the working modes,and shows the software flowchart and the measuring results.
基金supported by the National Natural Science Foundation of China(No.60821001)the National Basic Research Program of China(No.2007CB311203)
文摘Recently, the Internet of Things (loT) has attracted more and more attention. Multimedia sensor network plays an important role in the IoT, and audio event detection in the multimedia sensor net- works is one of the most important applications for the Internet of Things. In practice, it is hard to get enough real-world samples to generate the classifi- ers for some special audio events (e.g., car-crash- ing in the smart traffic system). In this paper, we introduce a TrAdaBoost-based method to solve the above problem. By using the proposed approach, we can train a strong classifier by using only a tiny amount of real-world data and a large number of more easily collected samples (e.g., collected from TV programs), even when the real-world data is not sufficient to train a model alone. We deploy this ap- proach in a smart traffic system to evaluate its per- formance, and the experiment evaluations demonstrate that our method can achieve satisfying results.
文摘Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance Ⅰ of broken ends and output volt Ⅴ, when Ⅰ ≥60 mm, Ⅴ keeps constantly, the running speed v of wire-core belt has no big effect on output volt Ⅴ, there is inverse proportion between the height h from probe to the surface of the belt and output volt Ⅴ, when h≥30 mm, Ⅴ tends to be zero. Based on the test result, on-line monitoring installation is developed, the practice proved that the accuracy of broken wire monitoring can be above 95%, the monitoring accuracy of joint twitch can be 0 .04 Ⅴ/mm.
基金Supported by National High Technology Research and Development Program ("863" Program) of China (No.2008AA04Z136)National Natural Science Foundation of China(No.50975197)+1 种基金Cooperation Project in Industry,Education and Research of Guangdong Province and Ministry of Education of China(No.2007A090302105)Tianjin Research Program of Application and Advanced Technology (No.09JCZDJC24000)
文摘In this paper,the sensors array technique is applied to the quality detection of aluminum alloy spot welding.The sensors array has three forms,i.e.,linear magnetic sensors array,annular magnetic sensors array and cross magnetic sensors array.An algorithm based on principal component analysis is proposed to extract the signal eigenvalues.The three types of magnetic sensors array are used in the experiment of monitoring the signal.After the eigenvalues are extracted,they are used to build a relationship with ...
文摘A robot slide tactile sensor based on photoelectric devices is introduced.The sensor is mounted on the hydraulic manipulator and used in a soft grasp control system.The experimental results are also presented.
基金Supported by National Natural Science Foundation of China(No.50875193)
文摘Cameras can reliably detect human motions in a normal environment, but they are usually affected by sudden illumination changes and complex conditions, which are the major obstacles to the reliability and robustness of the system. To solve this problem, a novel integration method was proposed to combine hi-static ultra-wideband radar and cameras. In this recognition system, two cameras are used to localize the object's region, regions while a radar is used to obtain its 3D motion models on a mobile robot. The recognition results can be matched in the 3D motion library in order to recognize its motions. To confirm the effectiveness of the proposed method, the experimental results of recognition using vision sensors and those of recognition using the integration method were compared in different environments. Higher correct-recognition rate is achieved in the experiment.
文摘The mositure content inside the hermetic package of semiconductor device has been quantitatively measured by using in-site sensor technique and computer-aided-test system.The principle and apparatus for measurement are introduced.The results show good repeatability and consistency.This technology can be used as a standard test for controlling the moisture content within semiconductor device package.
文摘A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2 μm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter.