Fan speed control method
View Patent ↗A fan speed control method performing by a baseboard management controller includes following steps: obtaining a first temperature from a first temperature sensor, determining a first rotational speed according to the first temperature and a proportional-integral-derivative (PID) equation, wherein a proportional term of the PID equation is: ∫ 0 t f ( E V ( t ) , p ) [ EV ′ ( t ) ] 2 d t - ∫ 0 t - Δ t f ( E V ( t - Δ t ) , p ) [ EV ′ ( t - Δ t ) ] 2 dt ; where t denotes time, Δt denotes an interval time, EV(t) denotes an error between the first temperature and a set temperature when the time is t, EV′(t) denotes a first derivative of EV(t), ƒ(EV(t),p) denotes a coefficient of the proportional term, and controlling said at least one fan according to said at least the first rotational speed.
1 . A fan speed control method, performed by a baseboard management controller, comprising:
obtaining at least one first temperature from at least one first temperature sensor;
determining a first rotational speed according to the at least one first temperature and a proportional-integral-derivative (PID) formula, wherein a proportional term of the PID formula is:
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wherein t represents time, Δt represents a time interval, EV(t) represents an error between the at least one first temperature and a set temperature at time t, EV′(t) represents a first derivative of EV(t), and ƒ(EV(t),p) represents a coefficient of the proportional term; and
controlling at least one fan according to the first rotational speed.
2 . The fan speed control method of claim 1 , wherein
ƒ(EV(t),p)=0 when EV(t)<−10;
a setting range of ƒ(EV(t),p) is 2 to 5 when −10<EV(t)<5;
ƒ(EV(t),p)=20 when 5<EV(t)<10; and
ƒ(EV(t),p)=0 when 10<EV(t).
3 . The fan speed control method of claim 1 , wherein
an integral term of the PID formula is: ƒ(EV,i)×EV(t);
a derivative term of the PID formula is: ƒ(EV,d)×[EV(t)+EV(t−2Δt)−2EV(t−Δt); and
ƒ(EV,i) and ƒ(EV,d) represent coefficients of the integral term and the derivative terms, respectively.
4 . The fan speed control method of claim 1 , further comprising:
obtaining a second temperature according to a sensed temperature of a second temperature sensor;
determining a second rotational speed according to the second temperature and a default ratio;
determining a third rotational speed according to the first rotational speed and the second rotational speed; and
controlling the at least one fan using the third rotational speed.
5 . The fan speed control method of claim 4 , wherein obtaining the second temperature according to the sensed temperature of the second temperature sensor comprises:
determining whether the sensed temperature falls within a first default normal temperature range;
setting the second temperature to a default temperature when the sensed temperature does not fall within the first default normal temperature range; and
using the sensed temperature as the second temperature when the sensed temperature falls within the first default normal temperature range.
6 . The fan speed control method of claim 1 , wherein determining the first rotational speed according to the at least one first temperature and the PID formula is performed when the at least one first temperature falls within a second default normal temperature range.
7 . The fan speed control method of claim 6 further comprising: when the at least one first temperature does not fall within the second default normal temperature range, controlling the at least one fan according to an abnormal speed control table, wherein the abnormal speed control table includes a default minimum fan speed.
8 . The fan speed control method of claim 1 , wherein the at least one first temperature sensor includes a plurality of temperature sensors respectively positioned in a smart network card, an open computing project network card and a baseboard.
9 . The fan speed control method of claim 1 , wherein determining the first rotational speed according to the at least one first temperature and the PID formula is performed when the baseboard management controller is in a normal operational state.
10 . The fan speed control method of claim 9 , further comprising: when the baseboard management controller is not in a normal operational state, controlling the at least one fan by a complex programmable logic device.