A novel induction heating coil is proposed and designed as a shrink-fit tool holder. An electromagnetic field analysis of the coil with different winding methods is conducted using the ANSYS finite element analysis software and an appropriate coil structure is determined, based on the simulated electromagnetic field distribution cloud maps. The magnetic field in the X–Y plane is increased by one order of magnitude around the surface with the addition of the designed magnetic slot, as well as improving the magnetic leakage. The electromagnetic field strength in the middle of the coil is greatly increased, up to 2.312 × 104 A/m, by the addition of a designed magnetic ring covering the top of the coil. The distribution of the three-dimensional temperature field is obtained by the ANSYS workbench transient thermal analysis software, based on the selected coil. Hot-loading equipment used for shrink-fit tool holders are implemented with diameter-selection, power, and heating time-setting functions. Experiments on different types of tool holders are carried out to obtain optimal heating parameters and to verify the reliability of the implemented heating equipment. Through experimental testing, the inserting and pulling out temperature is found to be about 270 °C for the BT40-SF06 and about 285 °C for the BT40-SF10. According to the experimental results, the simulated temperature field is in good agreement with the measured result. The optimal heating parameters of the heating equipment are determined, which proves the correctness of the heating method of the shrink-fit tool holder.

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In this paper, the control problem is investigated for discrete time-varying delayed systems with stochastic uncertainty, external disturbance, and two-channel packet dropouts. Sliding mode functions with packet loss probabilities are proposed for the packet loss problem in the sensor–controller channel and the controller–actuator channel. Furthermore, by employing the Lyapunov–Krasovskii functional, some new stability conditions are established in terms of solvable linear matrix inequalities (LMIs), and H∞ performance is analyzed for the sliding mode motion of the system. Meanwhile, a sliding mode controller is designed to drive the system state to the pre-designed sliding surface. Moreover, the designed controller can be robust for two-channel packet dropouts, time-varying delays, stochastic uncertainty and external disturbance. Finally, two numerical examples are given to demonstrate the feasibility of the proposed theoretical method.