JP2003018889A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller capable of obtaining sufficient torque and large acceleration and reducing power consumption and a heating value due to reduction in current consumption. SOLUTION: This controller comprises a plurality of exciting coils 11, 12, 13 generating magnetic forces by energizing, a rotor rotated by the respective magnetic forces from the exciting coils 11, 12, 13, and a controller 4 for energizing the exciting coils 11, 12, 13. The controller 4 changes a pulse duration, as necessary, for the exciting coils 11, 12, 13 for exciting.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for controlling rotation of a step motor or the like. 2. Description of the Related Art As a motor control device of this type, there is known a motor control device which generates a rotating force on a rotor by changing a voltage value applied to an exciting coil. [0003] However, in the above-described motor control device, in the one-phase excitation control, when the load is large or when the starting and braking are performed, the torque is insufficient.
The two-phase excitation control has a problem that power is wasted when the load is small or when rotating at high speed. [0004] It is an object of the present invention to provide a motor control device capable of obtaining a sufficient torque while obtaining a sufficient torque and further reducing power consumption and heat generation by reducing current consumption. It is intended to be. [0007] In the motor control device according to the first aspect of the present invention, a plurality of exciting coils that generate a magnetic force when energized, A rotor that is rotated by each magnetic force and a controller that energizes the excitation coil are provided, and the controller is configured to energize the excitation coil by appropriately changing the pulse width. In the motor control device according to the present invention, even if the pulse width of one-phase excitation and the pulse width of two-phase excitation are individually changed, the pulse width of one-phase excitation and the pulse of two-phase excitation are changed. In view of the well-known theory that if the sum of the widths is constant, the average rotation speed is constant, and the one-phase excitation is maintained while keeping the sum of the pulse widths of the one-phase excitation and the two-phase excitation constant. And the pulse width of the two-phase excitation are individually changed. That is, the ratio between the pulse width of one-phase excitation and the pulse width of two-phase excitation is changed. Then, a combination of the pulse width of the one-phase excitation and the pulse width of the two-phase excitation that can obtain the maximum torque for a certain rotation speed can be obtained. As a result, a larger torque can be obtained by using a combination of the pulse width of the one-phase excitation and the pulse width of the two-phase excitation that provides the maximum torque. Then, the motor is accelerated by using a combination of the pulse width of the one-phase excitation and the pulse width of the two-phase excitation at which the maximum torque is obtained, that is, the pulse width of the one-phase excitation and the pulse width of the two-phase excitation are increased. By shortening the sum, a large acceleration is obtained. Furthermore, the current consumption is reduced by shortening the pulse width of the two-phase excitation while keeping the sum of the pulse width of the one-phase excitation and the pulse width of the two-phase excitation constant. As a result, power consumption and heat generation are reduced. FIG. 1 to FIG. 12 show an embodiment of a motor control device according to the present invention. The illustrated motor control device 1 includes first, second, and third excitation coils 11, 1
Motor 3, controller 4 having rotors 2 and 13 and rotor 2
It is composed of First, second and third excitation coils 11, 1
2 and 13 have one end connected to the power supply 20 and the other end connected to the first and second power supply 20.
Second and third switching transistors 21, 22, 2
3 is connected. The first, second, and third switching transistors 21, 22, and 23 respectively turn on the first, second, and third excitation coils 11, 12, and 13 by turning on the output ports 4a, 4b, and 4c of the controller 4. Let it. The controller 4 has a built-in counter CNT for measuring the output pulse width and an arithmetic processing unit. The controller 4 is constructed as shown in FIGS.
(C), (d), (e), (f), (g), (h),
(I), (j), (k), (m), (n), FIG.
(A), (b), (c), (d), (e), (f),
(G), (h), (i), (j), (k), (m),
The control operation is performed based on the schematic diagram shown in (n), the time chart shown in FIG. 5, and the flowchart shown in FIG. In step 1, "the counter variable X of the motor rotation amount is initialized to" 0 "and the acceleration control is started. Are executed. During the acceleration control, steps 8 and 20 are executed.
Is determined as acceleration control. Initialization of the state of the motor rotor is started, and in step 2, "set the variable P indicating the output state of the motor coil to 2 and set the motor output state corresponding to the variable P using the output state table." Is executed. The output state table is shown in FIG. It is referred to as rotor state 1-6 which is stable for each state of P = 1-6.
Rotor states 1-6 are shown in FIGS. 2 (a), (b), (c),
(D), (e), and (f). In step 3, "stabilization wait" is executed. The state becomes the fixed state or the rotor state 2. Alternatively, the control waits until a state other than the rotor state 4 is set. Where P
If the motor output state corresponding to P = 1 of 4 is set from the beginning without setting the motor output state corresponding to P = 2, the following problems may occur. That is, when the initial state of the rotor is the rotor state 4, no rotational force is generated for the motor output state of P = 1. Therefore, the rotor may not be initialized to the correct state = rotor state 1. Therefore, a motor output state corresponding to P = 2 is set, and the process waits until the rotor enters rotor state 3 or rotor state 2. If rotor state 3 and rotor state 2 are reached,
Rotational force is generated for the motor output state of P = 1. The initial state of the rotor is in rotor state 5, and P =
If the motor does not move with respect to the motor output state of No. 2, the rotor state 5 becomes a rotor state 1 through the rotor state 6 due to the generation of a rotational force with respect to the motor output state of P = 1, so the problem is Absent. When the initial state of the rotor is near rotor state 5 and responds to the motor output state of P = 2, when rotor state 4 or near rotor state 4, P
When the motor output state of = 1 is set, no rotational force is generated. In such a case, the motor output state of P = 2 is maintained until the state changes to the rotor state 2 or the rotor state 3 after passing through the rotor state 4 or for a time sufficient to reach the rotor state 3. There is a need to. In step 4, "set P to 1" is executed, and the motor output state for P is set using the output state table. In step 5, "stabilization wait 2 is executed. It waits for a certain period of time or until it becomes stable in rotor state 2. This completes the initialization of the state of the motor rotor. In step 6," 1 phase ON pulse The variable T indicating the sum of the pulse width and the pulse width at the time of two-phase ON is “T0”
Initialize with In step 7, the counter CNT for measuring the output pulse width is set to "0".
Initialize with In step 8, the "one-phase ON pulse width T1 and the two-phase ON pulse width T2" are set.
Is obtained from T and a pulse width table or a function using T as an argument. The pulse width table and the function are shown in Fig. 11. The pulse width table and the function are stored as a data table in the controller 4. In the acceleration control, the low speed control, and the deceleration control, In FIG. 11 showing an example of the pulse width table, when this example is represented by a function, T1 = T / 2, T2 = T−T1, (T ≧ 16) T1 = T / 4 + 4, T2 = T−T1, (8 ≦ T <16) T1 = T × 3/4, T2 = T−T1, (T <8) During acceleration control, when the rotational speed is 2 / T, By setting a combination of T1 and T2 that gives the maximum acceleration torque (the maximum value of the applied force without deviating from the control when applying a force in the direction in which the motor decelerates), a large acceleration can be obtained. When the acceleration control A table or a function is set as described above, but when a combination of T1 and T2 that can obtain the maximum deceleration torque (the maximum value of the force applied without deviating from the control when the force is applied in the direction in which the motor accelerates) is set. In the constant speed control, when the load W applied to the motor can be detected, or when the load can be obtained by a function using the motor rotation amount X or the motor rotation speed 2 / T as an argument. Changes the pulse width ratio according to the load so that a necessary and sufficient torque is obtained, and at this time, the pulse width table (or function) uses T and the load W as arguments. In FIG. 12 showing an example of the obtained pulse width, when this example is represented by a function, T1 = T, T2 = 0, (W = 0, T ≧ 2) T1 = 2, T2 = 0, (W = 0, T <2) T1 = T × 3/4, T2 = TT 1, (W = 1, T ≧ 4) T1 = 3, T2 = 1, (W = 0, T <4) T1 = T / 2, T2 = T−T1, (W = 2, T ≧ 8) T1 = 4, T2 = 4, (W = 0, T <8) Normally, a table and a function are selected so that T = T1 + T2. In the case where it is desired to provide, for example, when the rotational speed at the time of the load W = 0 is to be up to 2/2 (T = 2 with respect to 2 / T), even in the region of T <2 as in the illustrated table / function, The combination T1-2, T2 = 0 (T = T1 + T2 = 2) of T1 and T2 that can obtain the rotation speed 2/2 is set as follows: In the illustrated table / function, W = 0 rotation speed upper limit = 2/2 (T1 = 2, T2 = 0,
T = 2) W = 1 Rotational speed upper limit = ２ (T1 = 3, T2 = 1,
T = 4) W = 2 Upper rotational speed = 2/8 (T1 = 4, T2 = 4,
T = 8). The characteristics of the pulse width corresponding to the load fluctuation are shown in FIGS. If the load is not known, a table / function for the assumed maximum value Wmax of the load is set and used. In that case, only the arguments of the table and the function are available. The pulse width table shown in FIG. 12 is stored in the controller 4 as a data table. In step 9, "P is increased by" 1 ". If it is determined in step 10 that “P exceeds 6”, then in step 11 “P is reduced by“ 6 ”. In step 12, "the motor output state corresponding to the new P is set. In step 13, "whether the motor output state is a two-phase output state (a state of two outputs ON and one output OFF) or a one-phase output state (a state of one output ON and two outputs OFF) is determined. In this embodiment, when P is an even number, it is in a one-phase output state, and when it is an odd number, it is in a two-phase output state, so that it is used to determine that P is an even number. , Step 15, step 1
6. In step 17, the position of the rotor is determined. That is, if it is determined in steps 14a and 14b that the rotor is behind the motor output state, T1 is extended in step 17a or T2 is extended in step 17b. If it is determined in steps 15a and 15b that the rotor is advanced with respect to the motor output state, T1 is reduced in step 16a or T2 is reduced in step 16b. In step 18a, "T1
If it is determined that time has elapsed, that is, CNT ≧ T1, the process proceeds to step 20. In step 18b, “T
If it is determined that 2 hours have elapsed, that is, CNT ≧ T2, the process proceeds to step 20. In steps 19a and 19b, “increase CNT by“ 1 ”” is executed,
Returning to steps 14a and 14b, steps 14a and 14b to steps 19a and 19b are repeatedly executed. In step 20, it is determined whether or not the vehicle is accelerating. If it is determined in step 20 that "acceleration is in progress", the process proceeds to step 24, where "the pulse width change amount .DELTA.T is set to .DELTA.T = f (T1 + T2, T) from the function f". Normally, ΔT <0, and T decreases in T = T1 + T2 + ΔT in step 25,
Speed 2 / T increases. As an example of the function f, when the position of the rotor is not determined, the constant acceleration control is executed by the following equation. ΔT = 2 / (2 / T + K) −T Here, K is a constant that determines the acceleration of the motor, and K> 0, and as a result, ΔT <0. In the case of (A) in which the position of the rotor is determined, ΔT = T1 + T2-T. In steps 14 to 17, when T1 is corrected by δ and new T1 = old T1 + δ, T
Is the old T1 + T2, so that ΔT = new T1 + T2-old T1-T2 = δ. Therefore, in step 25, the new T1 + T2 +
ΔT = (old T1 + δ) + (T2 + δ), and T2 is also δ
It is predicted that only changes. Step 14
In steps 17 to 17, similarly, when T2 is corrected, it is predicted that T1 changes by δ.
In the case of (B) in which the position of the rotor is determined, ΔT = 0. In this case, T1 is not predicted, and T1 and T2 are corrected in steps 14 to 17 depending on the position of the rotor. Will wait until In this case, the change in the rotation speed becomes slower than in FIG. In the case of (C) in which the position of the rotor is determined, (B) when the motor accelerates, and (A) when the motor decelerates. In particular,
If ΔT <0 in (A), change ΔT = 0. Generally, during acceleration, the motor rotor state is controlled in a state delayed from the motor output control state. In this case, if the vehicle can be accelerated, the vehicle is accelerated gently. If the vehicle needs to be decelerated, the vehicle decelerates quickly. In step 21, it is determined whether or not the vehicle is decelerating. If it is determined in step 21 that "the vehicle is decelerating", the process proceeds to step 23 where "the pulse width change amount .DELTA.T is set to .DELTA.T = g (T1 + T2, T) from the function g". Usually, it is determined whether or not ΔT acceleration is in progress.If it is determined in step 20 that “acceleration is in progress”, the process proceeds to step 24 and the “pulse width variation Δ
Let T be ΔT = f (T1 + T2, T) from the function f. "
Is executed. Usually, ΔT> 0, and step 25
T = T1 + T2 + ΔT, T increases, and the speed 2 /
T decreases. As an example of the function g, when the position of the rotor is not determined, the constant acceleration control is executed by the following equation. ΔT = 2 / (2 / TK) −T Here, K is a constant that determines the deceleration of the motor, and K> 0, and as a result, ΔT> 0. In the case of (A) in which the position of the rotor is determined, ΔT = T1 + T2-T. In steps 14 to 17, when T1 is corrected by δ and new T1 = old T1 + δ, T
Is the old T1 + T2, so that ΔT = new T1 + T2-old T1-T2 = δ. Therefore, in step 25, the new T1 + T2 +
ΔT = (old T1 + δ) + (T2 + δ), and T2 is also δ
It is predicted that only changes. Step 14
In steps 17 to 17, similarly, when T2 is corrected, it is predicted that T1 changes by δ.
In the case of (B) in which the position of the rotor is determined, ΔT = 0. In this case, T1 is not predicted, and T1 and T2 are corrected in steps 14 to 17 depending on the position of the rotor. Will wait until In this case, the change in the rotation speed becomes slower than in FIG. In the case of (C) in which the position of the rotor is determined, (B) when the motor accelerates, and (A) when the motor decelerates. In particular,
If ΔT <0 in (A), change ΔT = 0. Generally, during deceleration, control is performed in a state where the motor rotor state is ahead of the motor output control state. In this case, if acceleration is required, it is accelerated slowly,
If the vehicle can be decelerated, if the vehicle decelerates gently, the deviation from the control is reduced, so that the control as shown in FIG. In step 22, since constant speed control is being performed, T is kept constant at the target value Tx. If the position of the rotor can be determined and the value of T1 + T2 and the value of Tx corrected in steps 14 to 17 are significantly different, deceleration is started if Tx> T1 + T2, and Tx <T1 +
If T2, acceleration is started. When the acceleration control is started, it is determined in steps 8 and 20 that the vehicle is accelerating. When the deceleration control is started, it is not determined in steps 8 and 20 that the vehicle is accelerating, and it is determined in steps 8 and 20 that the vehicle is decelerating. If it is determined in step 26 that T is close to the pulse width target value Tx (the target rotation speed is 2 / Tx), "start constant speed control" is executed in step 27, and in the constant speed control, step 8 is executed. , It is not determined that the vehicle is accelerating in step 20, and it is not determined that the vehicle is decelerating in steps 8 and 20. Step 2
In step 8, "increase the motor rotation amount by" 1 "is executed, and in step 29," whether or not the motor rotation amount X has reached the deceleration start position "is determined.
If it is determined in step 9 that "the motor rotation amount X has reached the deceleration start position or the movement amount of the load can be measured and the movement amount has reached the deceleration start position", then in step 30, "deceleration control Is started. "Is executed. When the deceleration control is started, Step 8, Step 2
At 0, it is not determined that the vehicle is accelerating. In step 31, it is determined whether or not the motor rotation amount X has reached the target position. Step 3
In step 1, when it is determined that "the motor rotation amount X has reached the target position, or that the movement amount of the load can be measured and the movement amount has reached the deceleration start position", the control is ended. However, the motor rotation speed 2 / T at that time
However, when the motor is too large to stop at that position (ie, when deceleration fails), the deceleration control is continued until the motor can be stopped, the motor is stopped, and the motor is moved beyond the target position as necessary. Control is performed to rotate the motor in the reverse direction by the amount of rotation. If the motor rotation amount X or the load movement amount has not reached the target position,
Returning to step 7, the motor control is continuously performed. As described above, by using a combination of the pulse width of the one-phase excitation and the pulse width of the two-phase excitation that can obtain the maximum torque, a larger torque can be obtained and the one-phase excitation that can obtain the maximum torque can be obtained. A large acceleration can be obtained by accelerating the motor using a combination of the excitation pulse width and the two-phase excitation pulse width. By reducing the pulse width of the two-phase excitation while keeping the sum of the pulse width of the one-phase excitation and the pulse width of the two-phase excitation constant, current consumption is reduced, and power consumption and heat generation are reduced. It will be. As described above, since the motor control device according to the present invention has the above-described configuration, it is possible to obtain not only a sufficient torque but also a large acceleration, This leads to an excellent effect that power consumption and calorific value can be reduced by reducing the amount of heat.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit configuration diagram of an embodiment of a motor control device according to the present invention. FIGS. 2 (a), (b), (c), (d), (e),
(F) is a schematic diagram explaining a state of a rotor in the motor control device shown in FIG. 1. FIGS. 3 (a), (b), (c), (d), (e),
(F), (g), (h), (i), (J), (k),
(M), (n) is a schematic diagram explaining motor output and standby in the motor control device shown in FIG. FIGS. 4 (a), (b), (c), (d), (e),
(F), (g), (h), (i), (J), (k),
(M), (n) is a schematic diagram explaining motor output and standby in the motor control device shown in FIG. FIG. 5 is a time chart for explaining a control operation in the motor control device shown in FIG. 1; FIG. 6 is a characteristic diagram of the motor control device shown in FIG. FIG. 7 is a characteristic diagram of the motor control device shown in FIG. FIG. 8 is a characteristic diagram of the motor control device shown in FIG. FIG. 9 is a flowchart of a control operation in the motor control device shown in FIG. 1; FIG. 10 is an output state table used for controlling the motor control device shown in FIG. 1; FIG. 11 is a pulse width table used for controlling the motor control device shown in FIG. 1; FIG. 12 is a pulse width table used for control of the motor control device shown in FIG. 1; [Description of Signs] 1 Motor control device 2 Rotor 4 Controller 11 (Exciting coil) First exciting coil 12 (Exciting coil) Second exciting coil 13 (Exciting coil) Third exciting coil

Claims (1)

Claims: 1. An electronic apparatus comprising: a plurality of exciting coils that generate a magnetic force when energized; a rotor that is rotated by each magnetic force from the exciting coils; and a controller that energizes the exciting coils, respectively. The motor control device, wherein the controller energizes the exciting coil by appropriately changing a pulse width.