Kinematic analysis of mechanisms kinematic synthesis of mechanisms simple mechanisms and coupler curves cams spur gears helical, spiral, worm and bevel gears gear trains hydrodynamic lubrication static force analysis inertia force analysis combined static and inertia force analysis turning moment diagram and flywheel balancing of rotating components balancing of reciprocating components gear forces.

Mechanism and machine theory

A review of modelling and analysis of morphing wings

The combination of nonlinear spectrum and convolutional neural network (CNN) is efficient for fault diagnosis of nonlinear system. However, in traditional method, the nonlinear spectrum calculation was accomplished by identification algorithm outside the CNN, which reduced the diagnosis efficiency. To solve this problem, a novel CNN with the function of spectrum calculation and fault diagnosis is designed, in which the spectrum calculation network and the fault diagnosis network are connected in series. By extracting the optimized parameters of network, the nonlinear spectrum based on generalized frequency response function (GFRF) is obtained in the former network. Then, the GFRF spectrum is automatically put into the latter network for feature extraction and diagnosis. Hence, after determining the structure of the CNN, only by system input and output, the fault diagnosis can be realized, which avoids the complex process in traditional method. What's more, a new error cost function model is designed to guide the network parameters optimization in the direction of feature classification, which is conductive to improve the diagnosis accuracy. The proposed network model is applied to the heavy-duty industrial robot system, and the best performance is demonstrated by several experiments.

Application of Generalized Frequency Response Functions and Improved Convolutional Neural Network to Fault Diagnosis of Heavy-duty Industrial Robot

Parallel kinematic manipulators (PKMs) are increasingly used in a wide range of industrial applications due to the characteristics of high accuracy and compact structure. However, most of the existing PKMs are structured with heavy actuators and high stiffness. In this respect, this article proses a simple, yet effective, parallel manipulator that distinguishes itself through the following basis. First, underactuation: it employs only a single motor and a driving cable to actuate its three legs. Second, novel foot location: it uses a smart shape memory alloy clutch-based driving system (SCBDS), which catches/releases the driving cable, thus, making possible the robot underactuation. Finally, adjustable compliance: its double compliant joints on each limb with a stiffness-adjustable section, which renders a safe human–robotic interaction. To support and predict the performance of this underactuated compliant manipulator, a novel kinetostatic model was developed by considering the generalized internal loads (i.e., force and moment) in three compliant limbs and the external loads on the upper platform. Finally, based on the physical prototype, a set of experiments were conducted to validate the model proposed in this article. It was found that the proposed kinetostatic model can be validated with the average deviations of 1.8% in position and 2.8% in orientation, respectively. Furthermore, the workspace of the system (e.g., discrete and continuous workspace) was studied when different actuating strategies were employed, thus, emphasizing the advantages and the limitations of this novel system.

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Modeling and Experimental Validation of a Compliant Underactuated Parallel Kinematic Manipulator

Parametric vibration analysis and validation for a novel portable hexapod machine tool attached to surfaces with unequal stiffness

Design and stiffness analysis of a class of 2-DoF tendon driven parallel kinematics mechanism

Design and Analysis of a Bat-Like Active Morphing Wing Mechanism

The clutch system is increasingly utilized in a large range of industrial applications due to its working characteristics (i.e. clamping and releasing). However, in conventional design of the clutch, the electromagnet is mostly selected as the actuator to drive the motion, which makes the clutch Bulk and heavy. In this paper, a novel SMA wire-based clutch is proposed to overcome the aforementioned disadvantages of conventional clutches, aiming to reduce the weight and shorten the response time. To achieve this, an SMA wire was selected and twisted around the clutch to drive the motion of the moveable platform. The voltage-displacement response of the SMA clutch was studied, and the appropriate controlling voltage and heating time were obtained. After that, the tracking response of the SMA clutch was checked to study the dynamic working characteristics. It can be found that the proposed SMA clutch can track the given sinusoidal trajectory with high accuracy in the clamping area (i.e. 3.4%). Promisingly, with the studies of the proposed SMA clutch, it can be used in environments (e.g. satellite) where the weight is restricted.

Nan Ma

Papers

Design and stiffness analysis of a class of 2-DoF tendon driven parallel kinematics mechanism

Modeling and Experimental Validation of a Compliant Underactuated Parallel Kinematic Manipulator

Parametric vibration analysis and validation for a novel portable hexapod machine tool attached to surfaces with unequal stiffness

Design and Analysis of a Bat-Like Active Morphing Wing Mechanism

A Novel Shape Memory Alloy (SMA) Wire-Based Clutch Design and Performance Test