To ensure the motor drive performance while saving cost in the field of electric industrial vehicles, low-precision encoders are often adopted. Although these encoders can measure the rotor’s accurate mechanical position, they introduce a long delay and large errors to the measured speed information. Therefore, the traditional load torque observers cannot obtain the accurate load torque information, and when the inaccurate information is used as feedforward of the current loop, the motor speed fluctuation cannot be effectively suppressed. To solve this problem, a second-order sliding-mode load torque observer based on a low-precision encoder is proposed, which can obtain the accurate load torque information based on the rotor position information and thus improve the anti-interference performance of the system. Finally, the correctness and effectiveness of the proposed method was verified by simulation and experimental results.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |