JPS5937675B2 - Direct current linear motor running speed control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new speed control method for accelerating and decelerating a DC linear motor vehicle to a desired speed.

As this type of speed control that has already been carried out, the self-control control method and the division control method are known.

This self-control control system, needless to be described in detail, is based on detecting the positional relationship between the field of the traveling vehicle and the armature coil provided on the ground side with a predetermined number of phases (number of phases: N). , which controls the timing of supplying current to the armature coil phase determined by the target speed and the vehicle speed (
Usually, in the commutation method of a linear motor, the commutation order is determined in advance, and the commutation is performed in accordance with that order.

), therefore, since the current to the armature coil phase is commutated based on the position signal obtained by the position detection, there is an advantage that problems such as step-out and hunting due to external disturbances do not occur. However, this method detects the speed of the vehicle and changes the timing of commutation accordingly to control the average thrust received from the field armature coil from the maximum thrust to the maximum braking force. , arithmetic processing is required to determine the timing, and therefore, it has been pointed out that the delay in the arithmetic processing time limits the running speed, especially when traveling at very high speeds. On the other hand, the other-control control method performs commutation at a predetermined timing based on the thrust of the DC linear motor and the coil length L of the armature coil in accordance with the speed of the vehicle, without being based on position detection. , has the advantage of being able to easily run at a constant speed by commutation at a constant cycle, but since it does not have a feedback system like the former, there is a risk of loss of synchronization or loss of control due to external disturbances. Furthermore, during acceleration/deceleration, a large number of commutation patterns for the above-mentioned timing must be stored, and the equipment configuration is not simple. The present invention eliminates the shortcomings and drawbacks of both of these methods,
The aim is to provide a new control system that combines the advantages and advantages of the above, and by providing a closed-loop control system with a position detection system, it is possible to prevent synchronization, etc., and to prevent commutation. The purpose is to simplify the circuit configuration without requiring speed detection and calculation processing to determine the armature coil phase, and without having to prepare many commutation patterns. .

To explain the present invention in detail with reference to drawings, FIG. 1 shows its overall configuration, and by sending a commutation signal 2 from a control logic circuit 1 as an output, current to the armature coil phase on the ground side is controlled. The circuit 1 receives as inputs a control clock signal 4 from a crystal oscillator 3 or the like, and a position detection signal 5 that detects where on the armature coil the field of the vehicle is located. be introduced.

Here, the control clock signal 4 is selected to have a set cycle T that substantially matches the commutation cycle when the vehicle runs at the desired target running speed v, and therefore, this set cycle is set to the above-mentioned cycle. If the coil length of the armature coil is L1, and the number of armature coil phases is ν, then it becomes T21.-, for example, as shown in Figure 2, 1T1▼L. For example, the control clock signal 4 may be oscillated at a cycle of 9V with T=- and transmitted to the control logic circuit 1.

This control clock signal 4 does not need to be synchronized in phase or cycle with the position detection signal 5, and may oscillate at a set cycle T completely independent from the position detection signal, etc. Of course, this T is determined by the target traveling speed v. If change L2 is made, then T
From the relationship of =1/-, the change VN will be made.

Thus, in the control logic circuit 1, the control clock signal 4
For each entry, the current conducting phase of the armature coil and
The armature coil phase in which the field is located is compared with the armature coil phase obtained by the position detection signal 5, and by this comparison, the current is passed to the next conducting armature coil phase according to the preset matrix of the circuit 1 (see Fig. 3). This creates a commutation signal 2 that causes the current to flow.

Here, Fig. 3 shows the relationship between the current conducting phase, the current position detection signal, and the next conducting armature coil phase. The current flow phases are "4-phase and 1-phase", "1-phase and 2-phase", respectively.
In the case of "2-phase and 3-phase" and "3-phase and 4-phase", the relationship of the next conducting armature coil phase to the "detection phase" of the current position detection signal is shown. In other words, referring to the table in the upper part of Figure 3, the table shows that the current flow phases are "4 phases and 1 phase".
phase”, the detection phase of the current position detection signal is “phase”.
4 phase and 1 phase", the next current carrying armature coil phase is "
4 phase and 1 phase (without changing the conducting phase), or if the current conducting phase is a phase other than the above, the next conducting armature coil phase is changed to the 1 phase of the next phase to be commutated. 2-phase. Hereinafter, the commutation signal 2 obtained in this way is used to determine whether Keiyukihama Orecho St9! I'm here
Six calamities? Since the f-whistle to the fourth phase are provided on the ground side, the position detection signal 5 is delayed in phase in the order of the same phase, and remains at a high level only while the field is present on the armature coil. During this high level, the current flows through the armature coil and a thrust force is applied to the traveling vehicle.

Fig. 2 shows the case where the vehicle is running at a speed equal to the target running speed v, and in the same figure, P1 to P are the control clock signals 4, which are used to control the control logic at every set period T. The pulses entering the circuit 1, A-J, represent the sections P1 to P.

Now, in section A of the same figure, if current is flowing through the armature coils of the 4th phase and 1st phase as shown as the conducting phase, commutation signal 2 will be output at pulse P1. , the one at the high level of the position detection signal 5 at this point is the fourth one.
phase and the first phase, the next current-carrying armature coil phase does not change according to the predetermined matrix of FIG. Even in the pulse P2, the position detection signal 5 is still in the fourth and first phases, so the flow phase does not change in the section C, and the vehicle continues to receive thrust from this.

Next, in pulse P3, since the position detection signal 5 is in the first and second phases, the current conduction phase is in the fourth and second phases as shown in FIG.
In the first phase, when the current position detection signal is the first and second phases, the matrix is configured so that the first and second phases become the next conducting armature coil phases. 1. The second phase becomes the flow phase, and in the next section E, thrust is still obtained by the flow of the first and second phases, and in pulse P5, the current flow phase is the first and second phases, and the position Since the detection signal 5 becomes the second and third phases, the next conducting armature coil phases become the second and third phases.

In this way, commutation of the flow phase occurs only at times A, b, c, d, . . . , and the vehicle continues to receive thrust. Of course, a reverse thrust is generated in the shaded portion in FIG. 2, but the average thrust exerted by the magnetic field as a whole is always positive, accelerating the vehicle toward the target traveling speed v. The program shown in FIG. , continues the flow to the relevant flow phase, and if there is a mismatch, stops the flow to the flow phase with the most advanced phase among the current flow phases of the armature coil, and continues the flow with the slowest phase. This means that the current is diverted to the armature coil phase following the current phase.

Now, Fig. 4 shows a state in which the traveling vehicle has accelerated from -V to a speed 5% slower than v, and Fig. 5 shows a state in which it has become 5% faster than v. In the figure, the position detection signal 5 is expressed as the signal width when traveling at the target running speed v, all of which remain unchanged, and the pulses P1' to P,', P1'', which should originally be displayed at constant intervals with the set cycle T, are shown.
~P,'' section A', B', Ct...AI, B''
, C''... are shown shorter in FIG. 4 and longer in FIG. 5, corresponding to the slower running speed.

Therefore, in the case of Figure 4, the commutation point a is similar to Figure 3.
′, b′, c′, d′, etc., the flow phase turns and thrust is obtained, but the reverse thrust acts as shown in the shaded area, so the large average reverse thrust When the average thrust gradually decreases and exceeds the maximum value, the average reverse thrust increases at once and then gradually decreases, repeating the process, and as it gradually approaches the target traveling speed V, the pulse interval length will be displayed longer. Therefore, the shaded area becomes larger and the average thrust becomes smaller as it approaches the speed v, but the average thrust always acts in the positive direction, and in this way the vehicle smoothly moves toward the target speed. It can be seen that the velocity approaches v.

Next, when the traveling vehicle becomes faster than v as shown in Fig. 5, when the position detection signal 5 remains unchanged as shown in Fig. 5, sections A'', B'', C'', D'', ``...The length will be displayed longer than in Figure 4, and this time, of course, thrust will also be obtained, and since reverse thrust will act as shown in the shaded area, the first to The average reverse thrust gradually becomes larger in the 4th phase, and then in the next 1st to 4th phases, the average reverse thrust becomes even larger. Eventually, the average reverse thrust always increases, and the average thrust is always negative. As a result, braking force is applied to the traveling vehicle, the vehicle approaches the target traveling speed, and speed control is performed.

Incidentally, in order to configure the control logic circuit 1 with this X,
Even when constructing a matrix as shown in FIG. 3, the purpose can be achieved with a relatively simple logic circuit such as an AND circuit or a flip-flop circuit, as illustrated in FIG.

That is, the Q of the two D-type flip-flop circuits 1 and 2,
The Q output signal (corresponding to the conducting phases 1, 3, 2, and 4 in order from the top of the figure) is a control clock signal (CLK) that is sent to each flip-flop circuit 1, 2 via an AND circuit 3. The configuration is such that each time an input is made, the current phases 1, 2, 3, and 4 are turned on and off in sequence as shown in Figure 5, and other AND circuits, OR circuits, and NOT circuits are used to change the current state. The conduction phase and the position detection signal are compared, and if the logic matches, the control clock signal (CLK) is output from the AND circuit 3.
If the logic does not match, the next control clock signal (CLK) is output.

Therefore, only when the current flow phase and the position detection signal do not match in logic can a change to the next flow phase occur. As described above, the present invention provides commutation of the armature coil in VN at the current moment for each control clock signal of the set cycle b that substantially coincides with the commutation cycle at which the target traveling speed of the vehicle is obtained. The current phase is compared with the armature coil phase where the field of the running vehicle is located, and based on the comparison result, phase commutation is performed so that the current flows to the next conducting armature coil phase according to the preset matrix of the control logic circuit. Because this is done, problems such as step-out do not occur as with the self-limiting control method. Moreover, the conduction phase and the position detection signal are compared for each pulse of this control clock signal, and based on the results, the rotation is performed according to a predetermined matrix. Since all you have to do is let it flow, there is no need for an arithmetic circuit like in the case of a self-limiting type.
Therefore, there is an advantage that no circuit modification is required for any kind of ultra-high-speed running.

Moreover, once the target traveling speed v is determined, it is only necessary to issue a control clock signal with a set period T corresponding to this, so there is no need to prepare numerous commutation patterns as in other control systems. In addition, if the matrix of logic circuits is appropriately configured, it is possible to apply a reverse thrust to the field as shown in Figure 4, which makes it possible to approach the target running speed extremely smoothly and effortlessly. , it is possible to reduce the ripple at this speed.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the overall configuration of a device for implementing the traveling speed control method according to the present invention, and FIG. 2 is an explanatory diagram of commutation signals when a traveling vehicle is traveling at one target traveling speed. Third
The figure is an explanatory table of the matrix preset in the logic circuit of the device, Figures 4 and 5 are explanatory diagrams of the commutation signal when the target travel speed is 5% slower and over the target speed, respectively. 1 is a control logic diagram showing an example of a control device for implementing the present invention. FIG. 1... Control logic circuit, 2... Commutation signal, 4... Control clock signal, 5...
Position detection signal.

Claims (1)

[Claims] 1. By timely commutating current to a desired phase of an armature coil (coil length: L) provided on the ground side with a predetermined number of phases (number of phases: N), the field of a running vehicle can be changed. In a DC linear motor designed to impart a desired forward and reverse thrust to the magnetic field, a set period (L/V・2 /N), and for each control clock signal, the current flow phase of the armature coil is compared with the armature coil phase where the field of the traveling vehicle is located, and based on the comparison result, the logic A running speed of a DC linear motor characterized in that the running speed of a running vehicle is controlled by performing phase commutation so that current flows to the next conducting armature coil phase according to a matrix configured of a circuit. control method. 2. If a comparison result of the matrix composed of logic circuits is obtained in which the current flow phase of the armature coil phase matches the armature coil phase where the field of the traveling vehicle is located, the corresponding Claims characterized in that the composition is configured such that if the current flow to the flowing phase is continued and an inconsistent comparison result is obtained, phase commutation is performed so that the current flows to the next flowing armature coil phase. The running speed control method for the DC linear motor according to item 1. 3. When a mismatched comparison result is obtained, the matrix for determining the next conducting armature coil phase is determined by stopping the current flowing to the conducting phase whose phase is most advanced among the current conducting phases of the armature coil, and 3. The running speed control system for a DC linear motor according to claim 2, wherein the current flow is switched to the armature coil phase next to the current flow phase having the slowest phase.