Signal generators are widely used in experimental courses of universities. However, most of the commercial tests signal generators are expensive and bulky. In addition, a majority of them are in a fixed working mode with many little-used signals. In order to improve this situation, a small sized and highly accurate economic signal generator based on DDS technology has been developed, which is capable of providing wave signals commonly used in experiments. Firstly, it is introduced the basic principles of DDS and is determined the overall scheme of the signal generator. Then, it proposes a design of the hardware, which include power supply module, display module, keyboard module, waveform generating module based on DDS chip, and the minimum system module based on C8051F010. The signal generator was designed to output sine and square waveforms, and the other achieved performances included the frequency range 0.1 Hz–12.5 MHz, the frequency resolution 0.05 Hz–0.1 Hz, the output amplitude 1.0–4.5 V, the frequency accuracy% and%, and the signal distortion% and%.
15 March 2021 in Mathematical Problems in Engineering
This paper presents a kinematic analysis for an open architecture 6R robot controller, which is designed to control robots made by domestic manufactures with structural variations. Usually, robot kinematic studies are often introduced for specific robot types, and therefore, difficult to apply the kinematic model from one to another robot. This study incorporates most of the robot structural variations in one model so that it is convenient to switch robot types by modifying model parameters. By combining an adequate set of parameters, the kinematic models, especially the inverse kinematics, are derived. The kinematic models are proved to be suitable for many classic industrial robot types, such as Puma560, ABB IRB120/1600, KAWASAKI RS003N/RS010N, FANUC M6iB/M10iA, and therefore be applicable to those with similar structures. The analysis and derivation of the forward and inverse kinematic models are presented, and the results are proven to be accurate.
20 April 2024 in Advances in Mechanical Engineering
This article introduces the design of a robot end effector, which can perform constant force grinding on a curved surface using a brush tool without accurately measuring the geometric data of the workpiece. It uses a bidirectional cylinder and spring to create a force balance system as an additional servo degree of freedom to control the grinding brush. The system adopts impedance control method, establishes a complete electric pneumatic model, and uses PID controller to control contact force by adjusting pneumatic pressure to maintain a constant grinding force on the surface. The test results indicate that the system can perform effective rust and paint removal tasks. For paint removal, the removal rate has been proven to be 99.3% through measurement using image processing software, while for rust removal, the results are at a similar level but reliable and quantifiable measurement methods are still being studied. The end effector can be installed on most general-purpose robots for grinding and has potential application value.
10 April 2017 in Journal of Electrical and Computer Engineering
A hybrid electrical bus employs both a turbo diesel engine and an electric motor to drive the vehicle in different speed-torque scenarios. The cooling system for such a vehicle is particularly power costing because it needs to dissipate heat from not only the engine, but also the intercooler and the motor. An electronic control unit (ECU) has been designed with a single chip computer, temperature sensors, DC motor drive circuit, and optimized control algorithm to manage the speeds of several fans for efficient cooling using a nonlinear fan speed adjustment strategy. Experiments suggested that the continuous operating performance of the ECU is robust and capable of saving 15% of the total electricity comparing with ordinary fan speed control method.
This study investigates the characteristics of helical abrasive brush filaments and aims at developing a mobile robot system to perform rust removal and polishing tasks. A finite element model that can analyze the filament deformation and force characteristics is presented. From the model, the relationships between the brushing force and other operating parameters can be predicted, which are essential for developing an autonomous brushing control system. The modeled results are compared with experimental results carried out on a specifically designed test rig, leading to considerably well converged comparisons. Many later studies can be carried out to develop optimal brush control strategies for autonomous rust removal or polishing tasks.