A piezoelectric stick–slip actuator with the inertial block structure is presented in an attempt to achieve smooth motion. Under asymmetric excitation, the inertial block produces different inertia, which can dynamically change the normal pressure between the stator and rotor to adjust the friction. During the slip stage, the driving arm produces a deflection away from the rotor, the normal pressure between the stator and rotor can be eliminated, and the angular impulse of the moment of friction force on the rotor can be almost reduced to zero. To verify the feasibility of the prototype, finite-element method simulation is performed. On the basis of the experimental system, the output characteristics of the prototype are systematically studied. The experimental results indicate that the prototype can achieve smooth motion under large pretightening displacement. The displacement curve under the load of 2.0 kg still shows good smoothness, and the resolution is 1.56 μ rad. This article proposes a new design concept of dynamic control of the normal pressure to achieve smooth motion for piezoelectric stick–slip actuators, even under heavy-load conditions, using the inertial block structure.

The UAV (unmanned aerial vehicle) accelerometer is a sensor that measures the acceleration of the UAV by detecting the components of gravity along the three axes. The use of self-powered technology in UAV accelerometers will become inevitable. This article proposes an asymmetric electrode arc triboelectric nanogenerator (ASA-TENG) based on the single-electrode mode. It is a potential self-powered acceleration sensor that is installed on the UAV to detect the acceleration in the cruise state. It is characterized by a simple structure, low quality, high sensitivity, large detection range, low cost, and environmental friendliness. Two ASA-TENG structures are stacked into a cross along the x-axis and y-axis to detect the components of actual acceleration along the two axes to detect the acceleration of random directions. Finally, the actual acceleration is obtained through the principle of acceleration synthesis, which can accurately detect the direction of acceleration. The ASA-TENG acceleration sensor can detect accelerations in the range of 0.1–40 m/s ² . It exhibits a high sensitivity, and its response time has a good fitting relationship with acceleration (R ² =0.997). In addition, the voltage signal amplitude generated by the ASA-TENG sensor shows negligible fluctuations after 6 hours of continuous operation. Comparison experiments with commercial acceleration sensor and the maximum relative error of only 2.9%. Therefore, the ASA-TENG acceleration sensors can be potentially used under cruise conditions of UAV as it presents numerous advantages.

In this paper, a data-driven predictive controller is designed for the start-up process of vehicles with automated manual transmissions (AMTs). It is obtained directly from the input-output data of a driveline simulation model constructed by the commercial software AMESim. In order to obtain offset-free control for the reference input, the predictor equation is gained with incremental inputs and outputs. Because of the physical characteristics, the input and output constraints are considered explicitly in the problem formulation. The contradictory requirements of less friction losses and less driveline shock are included in the objective function. The designed controller is tested under nominal conditions and changed conditions. The simulation results show that, during the start-up process, the AMT clutch with the proposed controller works very well, and the process meets the control objectives: fast clutch lockup time, small friction losses, and the preservation of driver comfort, i.e., smooth acceleration of the vehicle. At the same time, the closed-loop system has the ability to reject uncertainties, such as the vehicle mass and road grade.