The optimization of fire robot axle in axle size based on dynamic strength and material cost
The axle of robot always afford complex load in a high dynamic vibration, the statics strength cannot take enough safety factor, and a larger safety factor would waste the material cost. In this paper, a new optimization function which takes consideration to the dynamic strength and material cost is derived. The dynamic strength has been discussed, a dynamic simulation modle based on FEA has also been bulid, the simulation results showed the boundary conditions of the optimization, the relationship between dynamic strength and axle size which was highly nonlinear, was simplized as a approximated sine function. The material cost factor is simplified to the mess of the axle. And all the factors in the optimization plently funtion were normalized, and the 3D graphic of the funtion has been draw, the extremum point of the optimization function, which was the most appropriate sizes of the axle, was found by the Matlab.
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.
Active profiling and polishing for efficient control of material removal from large precision surfaces with moderate asphericity
We present the development of an active fabrication technology for controlling material removal on large precision surfaces of moderate departure from a sphere. The underlying philosophy was established as an efficient solution to the challenging problem of fabricating secondary mirrors of up to nominally 2.5 m in diameter for modern 8 m class telescopes and beyond. The facility described comprises a CNC profiler, two contact profilometers, and a full size active polisher. The trial work-piece was a convex surface of 830 mm in diameter on a zero-expansion ceramic (`Cervit') blank – a 1/3 scale hyperbolic mirror for a proposed 2.5 m diameter f/7 secondary mirror for the 8 m Gemini telescope. Using software error-correction from profilometric metrology data, a factor of 2 improvement in generating the convex aspheric profile was achieved. An active loose-abrasive polishing process is also described, in which a full-size tool is configured to deliver variable, edgeless, sub-diameter removal-footprints. Real-time monitoring of process variables is described, and approximately 10% convergence in each polishing pass is reported.