Shu Fang

The Analysis on Fire Smoke Exhausting Robot Vibration Based on Wavelet Transform

Belt relaxation, which affects a lot on operation reliability of the fire smoke exhausting robot, is hard to detect. In this paper, a new method for belt relaxation feature recognition based on continuous wavelet transform (CWT) is proposed, and a vibration model which simplified the robot as a 2-dof forced vibration system under harmonic excitation is established. The vibration acceleration signal has been collected using the IEPE sensor and data acquisition card, experimental results verified the accuracy of the vibration model, and weak impact signal caused by the belt relaxation was distinguished, that testify the practicability of the CWT method in belt relaxation feature recognition.

Pitting Corrosion Diagnosis of Bearing Based on Power Cepstrum and Histogram

The axle assembly of fire robot need endure both heavy load and high impact force, and the pitting corrosion in the bearing race become a commom fault. In this paper, the vibration of bearing both in the inner ring and outer ring was analyzed, the characteristics of bearing with pitting corrosion were also analyzed, and based on those characteristics a new method for pitting corrosion diagnosis were proposed, in this method the power cepstrum in the axial direction and histogram of the vibration amplitude in the radial direction were used for detecting the pitting corrosion of bearing, and experiments results proved the practicability and effectiveness of this method.

Fire Robot's Operation Quality Base on Sperling Value

The fire robot always bear high impact load due to the abominable fire environment and fatigue stress， this affects a lot on operation reliability and causes serious consequence. The operation quality of fire robot has been discussed in this paper, however, the kinetic energy and acceleration of vibration which have great influence on life cycle were analyzed, and Sperling Value, which definite by the acceleration and frequency, has been found for judging healthy condition of the robot. Furthermore, a set of method for measuring the vibration of robot has been proposed. The signal treated by Fourier Transform (FFT) and Sperling Value was calculated by a new algorithm. Experiments are made and the results demonstrated the practicability of the algorithm.

Turning Dynamics of Series Hybrid Power All-Terrain Vehicle

The complex and unstructured working environment of all-terrain vehicle cause large resistance when they are turning. The turning power which affects a lot on the mobility of all-terrain vehicle is much larger than the power in running straight. In this paper, a series hybrid power system of an all-terrain fire robot was discussed, the turning model of the robot is simplified to 2D mechanical model, force analysis was made, a power formula in which the power is only related to the drag coefficient and relative turning radius was derived, and a dynamic model based on the driving power of lateral side and the braking power of medial side has been set up, simulation has been made in the condition of paddy field, hard soil road and asphalt road, the simulation reults shows the characteristic curve of driving power and baking power in turning, and the extreme power needed in turnning have been found.

A Local Feature Based Fusion Algorithm for Fire Detection Image

Image fusion is an very important process for fire detection, it generates a single combined image that contains a more accurate description of the fire scene than multiple images from different sources. In this paper, a local feature based fusion algorithm for fire detection image is proposed. Using the non-subsampled contourlet transform (NSCT), each of the visual and infrared fire detection images is decomposed into a low frequency and a set of high frequency subbands. Then the fused coefficients are generated by applying different local feature measure to the low frequency and high frequency subbands, respectively. And the fused image is obtained by taking inverse NSCT. Experimental results indicate that the proposed method outperforms other methods in both of fire target enhancement and background detail preservation.

The Analysis on Track-Memory of Omnidirectional Fire Robot

The track-memory of omnidirectional fire robot is so useful in locating the robot in fire scene, ultrasonic location nor map-matching nor other methods in self-orientation are not suitable for fire robot because of the precision requirement and response speed, in this paper, a simplified method based on inertial measurement unit (IMU) is proposed, in this method the position of robot is calculated by the acceleration and angular velocity , and iterative equation is derived , as the omnidirectional fire robot is always used as a translational device, the rotations of the robot in triaxial-axis are zero, a more practical algorithm based on the triaxial accelerometer is established. A fire robot model has been set up, experiment both with smoothing curve path and un-smoothing curve path have been made, , the trajectorys are iteratived by the practical algorithm, the experimental results demonstrated the practicability and accuracy of the new simplified method.