CFHBA-PID Algorithm: Dual-Loop PID Balancing Robot Attitude Control Algorithm Based on Complementary Factor and Honey Badger Algorithm.

The PID control algorithm for balancing robot attitude control suffers from the problem of difficult parameter tuning. Previous studies have proposed using metaheuristic algorithms to tune the PID parameters. However, traditional metaheuristic algorithms are subject to the criticism of premature convergence and the possibility of falling into local optimum solutions. Therefore, the present paper proposes a CFHBA-PID algorithm for balancing robot Dual-loop PID attitude control based on Honey Badger Algorithm (HBA) and CF-ITAE. On the one hand, HBA maintains a sufficiently large population diversity throughout the search process and employs a dynamic search strategy for balanced exploration and exploitation, effectively avoiding the problems of classical intelligent optimization algorithms and serving as a global search. On the other hand, a novel complementary factor (CF) is proposed to complement integrated time absolute error (ITAE) with the overshoot amount, resulting in a new rectification indicator CF-ITAE, which balances the overshoot amount and the response time during parameter tuning. Using balancing robot as the experimental object, HBA-PID is compared with AOA-PID, WOA-PID, and PSO-PID, and the results demonstrate that HBA-PID outperforms the other three algorithms in terms of overshoot amount, stabilization time, ITAE, and convergence speed, proving that the algorithm combining HBA with PID is better than the existing mainstream algorithms. The comparative experiments using CF prove that CFHBA-PID is able to effectively control the overshoot amount in attitude control. In conclusion, the CFHBA-PID algorithm has great control and significant results when applied to the balancing robot.

[Predictors of retention related factors at the initial methadone maintenance treatment clinics in Guangdong province].

OBJECTIVE: To identify predictors of treatment retention problems at the two initial methadone maintenance treatment (MMT) clinics in Guangdong province, and to provide reference in reducing the rate of drop-outs. METHODS: All of the patients were investigated at baseline and followed during the treatment period. Kaplan-Meier method on Survival Analysis was used to analyze retention related factors and predictors. RESULTS: 509 subjects were recruited in this study with median of retention time as 108 days (95%CI: 74 - 142 days). The retention rate at 1-, 3-, 6-, 12-months were 75.9%, 52.7%, 41.6%, 30.1%, respectively. Data from Multivariate Cox Proportional Hazard Model analysis showed predictors of retention would involve factors as HIV infection state at baseline (HR = 1.241, P = 0.047), daily methadone dose (HR = 0.633, P = 0.004) and secretly using drugs during treatment period (HR = 5.345, P = 0.000). CONCLUSION: The retention rates at the two initial MMT clinics in Guangdong province were low. Patients who were HIV negative at baseline but still secretly using heroine during treatment or accepted low daily average dosage of methadone, had the tendency to drop out. The results implied that retention time could be prolonged by increasing daily methadone dosage.