A smart micro-cantilever in a creative gas sensor with high sensitivity is presented. The resonance frequency shifting of
the cantilever is monitored to detect its mass change caused by adsorption of certain gas molecules. The cantilever has a
more compact MEMS structure and the smart functions because of the sensor with a self-actuating and detecting (SAD)
vibration system, which is integration of a vibration actuating system and a detecting system. The model of the smart
beam is analyzed by computer simulation. Design rules of the beam are obtained according to related discuss with
function goal of extremely rare gas detection. After fabrication and test of the smart cantilever, an improved solution of
the smart cantilever is introduced by comparison study of the computer simulation and experiment results of the
This paper provides one scheme of the on-board parallel computer system designed for the Nano-satellite. Based on the
development request that the Nano-satellite should have a small volume, low weight, low power cost, and intelligence,
this scheme gets rid of the traditional one-computer system and dual-computer system with endeavor to improve the
dependability, capability and intelligence simultaneously. According to the method of integration design, it employs the
parallel computer system with shared memory as the main structure, connects the telemetric system, attitude control
system, and the payload system by the intelligent bus, designs the management which can deal with the static tasks and
dynamic task-scheduling, protect and recover the on-site status and so forth in light of the parallel algorithms, and
establishes the fault diagnosis, restoration and system restructure mechanism. It accomplishes an on-board parallel
computer system with high dependability, capability and intelligence, a flexible management on hardware resources, an
excellent software system, and a high ability in extension, which satisfies with the conception and the tendency of the
integration electronic design sufficiently.
In this paper, the Bluetooth wireless data transmission technology is applied in on-board computer system, to realize
wireless data transmission between peripherals of the micro-satellite integrating electronic system, and in view of the
high demand of reliability of a micro-satellite, a design of Bluetooth wireless network based on fault-tolerant technology
is introduced. The reliability of two fault-tolerant systems is estimated firstly using Markov model, then the structural
design of this fault-tolerant system is introduced; several protocols are established to make the system operate correctly,
some related problems are listed and analyzed, with emphasis on Fault Auto-diagnosis System, Active-standby switch
design and Data-Integrity process.
This paper presents a method on how to reload the operating system on nano-satellite, in case of problems on the on-board computer subsystem. In this scheme, the ground station sends a command to the on-board computer subsystem to turn it on with the operating system reloaded. With the technology of operating system reloading, the reliability of the on-board computer subsystem is improved remarkably. It is very significant for the integration design and the integration electronic technologies for nano-satellite.
According to the digital imaging of remote sensing camera and informatics theory, information entropy is presented as the automatic exposure criteria for remote sensing camera and its performance is detailedly analyzed. Aiming at the characteristics of gray-level histogram at different exposure time and the relationships between image brightness and information entropy, improved MCS (Mountain Climbing Servo) is proposed to approach the optimal exposure time in short order. The proposed algorithm has been successfully tested to be effective on a subminiature CMOS remote sensing camera system developed by the authors. Experimental results demonstrate that the proposed criteria can adjust the exposure time automatically according to the image information with high speed, sensitivity and reliability. It is of great value for CMOS camera to improve the quality of space imaging.
Modern small satellites have been one of the hotspots of space technologies as the satellite technology develops. They represent the developing trend of smaller, faster, better and cheaper. Today more and more solid imaging sensors are utilized on modern small remote sensing satellites. But it’s difficult for the conventional CCD (Charge Coupled Device) to be fit on the satellites of around 10 kg, which require smaller size, lighter weight and lower power consumption remote sensing systems. CMOS (Complementary Metal Oxide Semiconductor) imaging sensor, which develops fast recently, provides an opportunity for such satellites. A CMOS remote sensing system was built, including the design of the optical and the electrical systems. Thermal experiments and radiation experiments were taken to research the performance of the CMOS camera under the space circumstance.