JP5212799B2 - Inductive load control device, control method, and control program - Google Patents

Description

  The present invention relates to a control device, a control method, and a control program for controlling a current flowing through an inductive load element.

  Conventionally, as a control device for controlling an inductive load element, an integrated circuit (IC) in which a control arithmetic unit (CPU) and a drive circuit system for the inductive load element are integrated is supplied to the inductive load element. Current control processing is performed. These ICs are for using PWM (Pulse Width Modulation) control to control the drive current that drives the inductive load element. This technique is disclosed, for example, in JP-A-11-308107 (Patent Document 1). Here, the inductive load element to be controlled is, for example, a solenoid of an electromagnetic actuator such as an automobile, and is used for various controls of the automobile to improve fuel consumption of the automobile or to move the automobile. It is used multiple times for the purpose of making things smoother. In this conventional control device, the plurality of inductive load elements are controlled in cooperation.

Japanese Patent Laid-Open No. 2000-35802 (Patent Document 2) obtains a difference between a data value and a value at the previous reception every time various data is received, and divides the difference by a detection interval time. Thus, it is disclosed that the amount of change per unit time of data is calculated.
Japanese Patent Laid-Open No. 11-308107 (Linear Solenoid Control ICs 14 and 54 (FIGS. 1 and 11 respectively)) JP 2000-35802 A (Claim 1 etc.)

  In order to more precisely control the operation of inductive load elements used in automobiles and the like, precise drive control is required. For this reason, the control method of drive control has increased complexity, and the load on the processing capacity of the control CPU has increased.

In response to this problem, if the control CPU and the drive circuit unit of the inductive load element are separated so that the process of the control CPU and the drive control of the inductive load element are distributed, the process of the control CPU The load can be reduced. As described above, when functions that have conventionally been operated as one IC are separated, it is necessary to transmit and receive control data using a communication path between them. In a conventional communication method for transmitting or receiving control data (for example, an interface such as I ² C or SPI), the number of bits of data flowing on the communication path is the maximum value of the data value that the data can take. It is determined by a communication protocol that defines the number of digits (the number of bits expressed in binary). As a result, communication is performed with a data amount that is not necessarily required to represent data. For example, when transmitting or receiving 4-bit data, even if the data value to be transmitted / received is 0 (0000B, B indicates binary representation), or 15 (1111B) Even if it exists, the bit length contained in the data transmitted at the time of communication shall be 4 bits. However, in order to improve the response accuracy of inductive load elements, the number of bits of data values to be transmitted as current setting values (or command values) of various data has increased, and the communication speed of the communication path is the same as before. Assuming that there is an increase in the number of bits, the time during which data is transmitted from the control CPU to the drive circuit section is delayed, and as a result, the response of the inductive load element connected to the sub-control circuit is delayed.

  An object of the present invention is to solve at least some of the above problems.

  In the present invention, a control device that performs communication by representing the difference before and after the current set value changes with control, that is, the code indicating whether the increase or decrease is an increase or decrease, and the range of the increase or decrease Is used. That is, according to the present invention, an inductive load control device that controls a current flowing through an inductive load element based on instruction data of an external host CPU and signals from various sensors, the instruction data of the external host CPU and A main control circuit for instructing a current setting value for a current flowing through the inductive load element based on the sensor signal by a current setting signal; a communication path for transmitting the current setting signal from the main control circuit; and the communication And a sub-control circuit that is connected to the inductive load element and controls a current value that flows to the inductive load element based on the current setting signal from the main control circuit. A bit string of data representing increase / decrease of the current set value is scanned from the MSB toward the LSB, and the bit immediately before the bit in which the valid bit first appears in the scan is scanned. Including a change amount data and the remaining bits of deleted data bits until note from the bit string, and command data for instructing the calculation of the variation amount data, inductive load control device is provided.

  Here, the sub-control circuit has an arithmetic unit for determining a current value to flow through the inductive load element and a current amplifying unit that actually controls the current, and one or more inductive load elements are connected. Can be. The sub control circuit may be a set of a plurality of control circuits. In this case, each control circuit may be provided with an arithmetic unit and a current amplifying unit for controlling the current flowing through the inductive load. In order to independently control a plurality of inductive load elements, a communication path can perform communication of a plurality of channels that are divided in time.

  The change amount data is data included in the current setting signal, and represents the increase / decrease value of the current setting value flowing through the inductive load. It should be noted that the change amount data can use a bit representation in an arbitrary form representing an absolute value. Positive and negative values can be represented by two's complement.

  Further, in this specification, the command data is an arbitrary code indicating how to perform the subsequent arithmetic processing. As an example, it is a code (increase / decrease code) indicating whether the increase / decrease is an increase or decrease. As another example, a code representing a 2's complement can be used. The command code can be expressed by data having a bit length of at least 1 bit such as 1 bit, 2 bits, and 3 bits. As will be described later according to the embodiment, the increase / decrease code and the code indicating 2's complement can be combined to form a 2-bit code.

  The range of bits that can be valid bits depends on the amount of increase or decrease in the current setting value. When the increase / decrease amount is indicated by a bit string, the effective bit is the range of bits that can be inverted when the data is changed so that the absolute value of the increase / decrease amount becomes small. is there. There are various modes in which data is represented by binary values, but the range of effective bits for each value does not vary depending on the representation.

  In the present invention, it is preferable that the change amount data is a data of a remaining bit deleted from the bit string based on the scan by scanning a bit string of data representing an absolute value of increase / decrease of the current set value. And the command data includes an increase / decrease code indicating whether the current set value has increased or decreased from the previous current set value, and the sub control circuit receives the current set signal, Depending on the data in the command data, the current data is selectively added to or subtracted from the previous current setting value to obtain a new current setting value, and the new current setting value is obtained. The value can be data of the current set value.

  In the present invention, as another preferred embodiment, the change amount data is obtained by scanning a bit string of data in a two's complement format representing increase / decrease of a current set value, and deleting the remaining data deleted from the bit string based on the scan Bit data, and the command data includes a code indicating that the change amount data is data in two's complement format, and the sub-control circuit receives the current setting signal, and the current setting signal When the data in the command data indicates that the amount of change data is two's complement data, the adder calculates the immediately preceding current set value data and the amount of change data. Thus, a new current set value can be obtained, and the new current set value can be used as data of the current set value.

  In one embodiment of the present invention, the main control circuit transmits the current setting signal through a plurality of channels that are time-divided in the current setting signal, and the sub-control circuit has a plurality of inductive load elements. Can be connected to receive the current setting signal for each inductive load element by each channel and control each inductive load element independently.

  In another embodiment, the main control circuit instructs the calculation for the first and second variation data by the command data together with the first variation data, and the current setting signal includes: Including first change amount data transmitted in association with the command data and second change amount data transmitted after the first change amount data, wherein the sub control circuit receives the received command data Can be applied to the calculation based on the first and second variation data.

  A method of inductive load control can be implemented. That is, in the present invention, using the main control circuit, the sub control circuit to which the inductive load element is connected, and the main control circuit and the communication path connected to the sub control circuit, the instruction data of the external host CPU and An inductive load element control method for controlling a current flowing through an inductive load element based on signals from various sensors, the current setting being a set value of a current passed through the inductive load element by the main control circuit A bit string of data representing increase / decrease in value is scanned from the MSB toward the LSB, and the change is the data of the remaining bits obtained by deleting the bits up to the bit immediately before the bit in which the valid bit first appears in the scan. A data generation step for generating quantity data and command data for instructing arithmetic processing of the change quantity data, and the main control circuit By transmitting a current setting signal including change amount data and command data through the communication path, a set value current to be supplied to the inductive load element based on the instruction data of the external host CPU and the sensor signal is The step of instructing by the current setting signal and the sub-control circuit that has received the current setting signal from the communication path cause the inductive load element to flow based on the current setting value of the current setting signal from the main control circuit And an inductive load control method including a control step of controlling current.

  The above method can also be implemented as a computer program.

  In any embodiment of the present invention, any of the following effects can be obtained. Since the amount of communication data is reduced, the transmission time from the main control circuit to the sub control circuit is shortened, the response time to the command is shortened, and the system operation with a faster response is possible. Further, since the communication time is reduced, the power consumption of the system for communication can be reduced. In addition, at least one of the above effects does not require a complicated circuit configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the configuration of a control system of a specific example using an embodiment of the inductive control device of the present invention. The system 100 of this embodiment includes a host CPU 5, an inductive load control device 10, and a sensor 7 connected to the host CPU 5 and the inductive load control device 10. The inductive load control device 10 includes a main control circuit 12, a communication path 14, and a sub control circuit 16, and the main control circuit 12 and the sub control circuit 16 are connected by the communication path 14. The sub-control circuit 16 is a drive circuit for the inductive load 9, and controls the drive current that is passed through the inductive load 9 by, for example, PWM control.

As shown in FIG. 1, not only one sub-control circuit 16 but also a plurality of sub-control circuits 16 can be provided. Here, N sub-control circuits of sub-control circuits (# 1- # N) 16 _{1 to} 16 _N are provided, and each is connected to the main control circuit 12 via the communication path 14. Inductive loads 9 _{1 to} 9 _N are connected to the sub control circuits (# 1 to #N) 16 _{1 to} 16 _N , respectively.

The main control circuit 12 determines a current set value for controlling a plurality of inductive loads 9 _{1 to} 9 _N based on a control command signal from the host CPU 5 and sensor signals from various sensors 7. The sub-control circuits (# 1- # N) 16 _{1 to} 16 _N are instructed through the communication path. Hereinafter, when it is not particularly necessary to specify individual sub-control circuits or inductive loads, the sub-control circuit 16 and the inductive load 9 will be collectively described.

FIG. 2 shows a timing chart of data communication between the main control circuit 12 and the sub control circuits (# 1- # N) 16 _{1 to} 16 _N in the communication path 14. In the present embodiment, an example of transmitting data having a configuration including 2-bit command data and 8-bit current setting signal data will be described, and the communication path 14 will be described by an example including a plurality of signal lines. The content of the present invention is not limited to this example.

Signals used for transmission on the communication path 14 include an ENn signal, a CLK signal, and a DATA signal. N of the ENn signal is a channel number, and the timing at which the main control circuit 12 and the sub control circuits 16 _{1 to} 16 _{N in} FIG. 1 communicate with each channel enables the corresponding ENn signal (n = 1 to N). Specified by. The CLK signal and the DATA signal are commonly used for a plurality of channels. For example, in the communication from the main control circuit 12 to the sub control circuit 16 or vice versa, the nth inductive load 9 _n has the ENn signal enabled among the DATA signals received by the sub control circuit 16 _n that controls it. The signal of the timing which is (it is in the Low level) is used. As shown in the timing chart of FIG. 2, this signal includes a 2-bit command followed by an 8-bit current setting value.

  FIG. 3 shows types of values to be entered in command data when performing data transfer. As shown in FIG. 3, the normal mode is set when the command data is 00B. The normal mode means that the data following the command data is 8-bit data. Further, when the command data is 01B, the data following the command data is increased by the amount indicated by the change amount data. When the command data is 10B, the data following the command data decreases by the amount indicated by the change amount data. When the command data is code 11B, it can be left undefined in an embodiment of the present invention. In this case, since it is undefined, the receiving side ignores this command. In this embodiment, the code 11B is assigned a case where a 2's complement is used.

FIG. 4 shows an example of the time change of the current set value for controlling one inductive load. FIG. 5 is a table showing the current setting values shown in FIG. Hereinafter, the driving current, as from time _{t 0} in FIG. 4 between _{t 7,} that is, from time _{t 0} to _{t 7,} (10 in decimal) 0,1,2,11,10,1,0,1 A specific embodiment in the case of setting to change is shown. The first column of Figure 5 represents a t ₇ the set time from the time t _0. The second column shows the current setting value at each time, and the decimal notation is converted into an 8-bit binary number. In the lowermost row of the same column, the amount of data transmitted by the current set value in the range shown in FIG. 4 is shown by the number of bits.

FIG. 5 also shows the current setting value expressed in hexadecimal in the third column. Specifically, the current setting value at time t ₀ is 0H (indicating that H is a hexadecimal representation. Forth.), The current setting value at time t ₁ is 1H, the current set at time t ₂ values 2H, current setting value at time _{t 3} is BH, the time the current set value when _{t 4} is AH, the current setting value at time _{t 5} is 1H, the current setting value at time _{t 6} is 0H, time t _{At 7,} the current set value is 1H. In FIG. 5, the fourth column shows the difference data, which is the difference between the current set value t _{(n-1) at the} previous time and the current set value t _(n) , in decimal numbers using positive and negative signs. (If the value is positive, the difference is incremented, and if it is negative, it is decremented.) The fifth column shows command data generated from the positive and negative signs of the difference data in the fourth column. The sixth column shows the absolute value data (change amount data) of the difference shown by the third column expressed in binary.

In FIG. 5, as shown in the second column, when all data is transmitted and received in 8 bits from time t ₀ to t _7, it is necessary to transmit 64-bit data, and the transmission time for 64 bits I need it. On the other hand, as shown in the fifth column and the sixth column, when command data and change amount data are transmitted in combination, the data amount is 16 bits and 14 bits, respectively, which is necessary for data transmission. The time is 30 bits. In this way, the data to be transmitted can be reduced in this embodiment.

  Next, the configuration of data transmitted in the present embodiment is specifically shown in FIG. FIG. 6 is different from FIG. 5 in the case where the bit length of the current set value is 16 bits. The left column of FIG. 6 shows 16-bit current setting value data, and the right column shows transmission data (current setting signal) actually transmitted. The upper part of each column in the right column shows the bit configuration when transmitting normal data as it is, and the lower part shows the difference data indicating the difference between the current setting value and the current setting value at the previous time. The bit configuration for transmission is shown. The MSB2 bit of the transmission data (current setting signal) is command data. It is assumed that the current setting values at the previous time for the three types of data in FIG. Since the current set value at the previous time is 0, the normal data current set value data can be regarded as difference data as it is. The data transmitted as the difference data shown in the lower part of each column in the right column is a command data having a 2-bit length, followed by the change amount data obtained from the current set value in the order of bits (see FIG. 6). In the example, it is equal to normal data as described above), and all the bits are scanned in order from the MSB toward the LSB, and the data from the first bit to the LSB are first arranged. Compared with the normal data transmission data, which is simply a combination of the 2-bit command data and the current setting value data in the left column of FIG. 6, the change amount data is shortened in this way, so the communication data amount is reduced. The communication time required for transmitting the current set value can be reduced.

FIG. 7 shows a transmission data creation flow. First, in the program of the main control circuit of FIG. 1, it is determined whether normal data is transmitted as data to be transmitted to the sub control circuit (S702). When transmitting normal data, the code to be inserted into the command data of FIG. 2 is set to 00B (S704). At this time, the current setting value data is directly input to the current setting signal (S706). By way of example the value of _{t 0} in FIG. 4 and 5 this, for use as a 8-bit data, 00000000B is used. If it is not normal transmission data (S702), a difference from the previous stored current setting value (0 when data is not saved) is detected (S708). Then, it is determined whether or not the increase / decrease amount is expressed by 2's complement (S710).

  When 2's complement is used, the code to be entered in the command data is set to 11B (S712), and data setting processing (data setting processing 2) when 2's complement is used is executed (S714). This process will be described later. If an absolute value is used (2's complement is not used), the process branches depending on whether the detected difference is positive or negative (S716). In S708 or S716, the absolute value of the difference is also obtained. If the difference is positive, the code entered in the command data is 01B (S718), and if the difference is negative, the code entered in the command data is 10B (S720). Thereafter, the data setting process 1 is performed on the absolute value of the difference by the process of FIG. 8 described later (S722), and the obtained data becomes the data to be transmitted. Finally, the current set value is temporarily stored in the storage element (S724). The stored data is used for difference detection.

  Next, regarding the process for setting communication data from the variation data and the process of reception, data processing setting 1 when using an absolute value (S722) and data processing setting 2 when using two's complement (S714) Details will be described. FIG. 8A shows a processing flow for the data processing setting 1 processing, and FIG. 8B shows a processing flow for the data processing setting 2 processing. In FIGS. 8A and 8B, the data of the current setting value is a bit string represented by DATA [7: 0] as 8-bit data. Here, the expression of specific N bits (N = m−n + 1) from bits m to n is expressed as DATA [m: n] (m> n ≧ 0). One specific bit is represented as DATA [m]. A general expression of the current set value is a bit string of DATA [N-1: 0].

  In data processing setting 1 (FIG. 8A) in the case of using an absolute value, first, a value of a parameter m representing a scanning bit position is initialized (S802). For general expression, if the number of data bits is M, it is initialized to m = M-1. Next, it is determined whether or not DATA [m] is 1 (S804), and if it is 1, only data [m: 0] is extracted from the data of the current setting value with the data bit width (number of bits−1) as m. (S806). Since communication data is determined in this way, the process ends. On the other hand, when DATA [m] is not 1, that is, when DATA [m] is 0 (S804), it is further determined whether m = 0 or not (S808). (Number of bits-1) = 0 and data value = 0. If m = 0 is not satisfied (S810), m is decremented (m = m-1) (S812), and this is repeated until DATA [m] becomes 1 again. This process scans each bit while decrementing m, and repeats the process until DATA [m] is 1 or m = 0, and the LSB from the bit that is first 1 in the change amount data The data bit width and data value up to are extracted. In other words, the data of the remaining bits obtained by scanning each bit and deleting the bits up to the bit immediately before the bit in which the valid bit first appears from the bit string is used as the change amount data. When all the bits are 0, data of 1 bit of 0 is used as the change amount data.

  Next, data processing setting 2 in the case of using 2's complement will be described. In this case, it is assumed that the 2's complement data itself has been obtained in S708 of FIG. 7, and the data processing setting 2 performs a process of reducing the communication data amount related to the 2's complement data. In this processing, when 2's complement data indicates a positive value, it is assumed that a bit of 0 continues for 1 to several bits from the MSB, and when it indicates a negative value, 1 bit continues for 1 to several bits from the MSB. It is said. Also in data processing setting 2 (FIG. 8B) in the case of using 2's complement, first, the value of the parameter m representing the scanning bit position is initialized (S832). Next, it is determined whether DATA [m] and DATA [m-1] are equal to each other, that is, whether they are equal to adjacent bit values (S834). If they are not equal, the data bit width (bit number-1) is set. Only DATA [m: 0] is extracted from the data of the current setting value as m (S836). Since communication data is determined in this way, the process ends. On the other hand, when DATA [m] is equal to DATA [m−1] (S834), it is further determined whether m = 1 (S838). If m = 1, DATA [m−1] is determined. Depending on whether (or DATA [m]) is 0 (S842), the data bit width = 0 and the data value = 0 (S844), or the data bit width = 0 and the data value = 1 (S846). This indicates whether the original data is data in which all the bits are zero or data in which all the bits are 1. It should be noted that all bits are 1 when the original 2's complement representation data represents a decimal number “−1”.

  If m = 1 is not satisfied (S838), m is decremented (m = m-1) (S840), and this is repeated until DATA [m] becomes 1 again. In this process, the amount of change expressed by the two's complement is changed by scanning each bit and removing the bits from the bit string up to the bit immediately before the bit where the effective bit first appears. It is data.

  FIG. 9 shows a data reception flow. When data reception is started when the ENn signal is changed from a high level to a low level, first, an m value indicating the number of bits for which scanning has been completed is initialized to m = 0 (S902). Note that data reception is performed at a timing defined by the CLK signal shown in FIG. When 1 bit is received, since the command code is 2-bit data, it is first determined whether m = 2 (S904). If m = 2 is not satisfied, the command code data storage variable CMD [1: 0] is stored in CMD [m] (S906), and the m value is incremented (m = m + 1) (S908). This is repeated until m = 2 (S904). When m = 2, CMD [1: 0] is stored as command code data (S910).

  Since the command data is data indicating the current value, the m value indicating the number of scanning bits is initialized to m = 0 again (S912). Thereafter, data reception is continuously repeated until the ENn signal changes from low level to high level (S914 to S918). When the data reception is completed (S914), DATA [m: 0] is acquired (S920). Then, based on the previously determined command data value (S922), when normal data is received (code 00B), the absolute value is used and the increase / decrease is positive (increase) (code 01B). ) When the two's complement is used (code 11B), the absolute value is used and the increase / decrease is negative (decrease) (code 10B). That is, when normal data is received, the received data DATA [m: 0] is set as it is in the current setting value (S924). Further, when the absolute value is used and the increase / decrease is positive (increase) (code 01B) and when the two's complement is used (code 11B), the current value changes with respect to the current setting value. DATA [m: 0] serving as quantity data is added (S926). Then, when the absolute value is used and the increase / decrease is negative (decrease) (S10B), when the increase command code is received according to the content of the command code, it changes from the current current set value. DATA [m: 0] which is quantity data is subtracted (S928). Through the above processing, a current set value in which the increase / decrease is appropriately reflected with a small communication amount can be obtained.

  In addition, although the above-mentioned Example 1 showed the example which combined the expression by an absolute value, and the expression by 2's complement, those skilled in the art are like S710 in embodiment which does not use 2's complement. It is clear that the decision and the branch when using the two's complement are not executed, and that in the embodiment using only the two's complement, the decision at S710 and the branch when not using the two's complement are not executed. is there. In any case, any effect of the invention of the present application to reduce the communication amount is achieved.

  In the embodiment using 2's complement, assuming that the number of input bits of the adder that performs the addition operation of S916 is N, if (N−1)> m, in the addition operation shown in S926, DATA [m :]] Is replaced with DATA [N-1: 0] with (N-1-m) bits added to the bits having the same value as DATA [m] as the higher-order bits of the MSB of DATA [m: 0]. Perform the operation.

  FIG. 10 shows a timing chart when transmitting and receiving a plurality of data continuously. FIG. 10 shows a case where data group 1 consisting of command 1 and data 1 and data group 2 consisting of command 2 and data 2 are transmitted continuously. The numbers 1 to 7 shown in the data 1 and the data 2 indicate the order in which the bits are arranged, not the data values themselves (the same applies hereinafter). Further, 1 and 1 shown in the command data 1 and the command data 2 have no particular meaning, and do not indicate that they are expressed in two's complement as in the first embodiment (the same applies hereinafter). As a communication decision, it is determined that the data group 2 always comes after the data group 1, and by composing the transmission / reception circuit sequence corresponding thereto, communication of these continuous data groups becomes possible. In FIG. 10, the discrimination between the data group 1 and the data group 2 is performed by changing the ENn signal from the low level to the high level only for one clock and again to the low level. FIG. 11 also shows a timing chart in the case where two data groups are transmitted and received in the same manner, but the data group 2 shows an example where only normal data is transmitted and received, and is an example in which the command 2 is omitted. FIG. 12 shows an example in which command 1 of data group 1 is omitted, contrary to FIG. In this case, since the number of bits of the data group 1 is fixed, it is not necessary to identify the data group 1 and the data group 2 by the ENn signal. The data groups 1 and 2 in FIG. 10, the data group 1 in FIG. 11, and the data group 2 in FIG. 12 have the same bit length as that of the normal data of 8 bits. According to the first embodiment, the data can be reduced in bit length. As shown in FIG. 10, by combining a plurality of data groups, signals for controlling a plurality of inductive loads can be communicated through a communication path. Further, a flexible communication mode can be realized by combining with normal data as shown in FIGS.

Next, as a third embodiment, an example in which a plurality of data not using the ENn signal is transmitted and received will be described. FIG. 13 shows a timing chart of an example in which this ENn signal is not used. Start the identification of the end of the data is the same as the state identification to be used in the interface, such as I 2 ^C, data of the data group 2 is not a fixed length, where using only the valid bit such as I ^{2 C} Different from conventional technology. The example of FIG. 13 is an example in which the data group 1 has a fixed bit length. However, as shown in FIG. 10, both the data group 1 and the data group 2 may be transmitted and received with only the effective bit length. As described above, only the effective bit length of the data group 1 may be transmitted and received, and the data group 2 may have a fixed bit length. In this case, for example, the end of the data group 1 can be detected by mimicking a restart condition used in I ² C or the like (when data is transmitted as a data signal, the timing of the change of the data signal is determined by the CLK signal). Is limited to a low level period, and if the data signal changes during a period when the CLK signal is at a high level, it is determined that the data group 1 has ended.) Further, the number of data groups to be transmitted is not limited to two, and transmission / reception can be continuously performed on two or more data groups in the same manner.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications, changes and combinations can be made based on the technical idea of the present invention. . For example, in the above-described embodiment, only the process in which the change amount data representing the absolute value of the increase / decrease in the current setting value is reduced to only the valid bits using the increase / decrease code is shown. For example, the change amount falls within a certain range. When fine control is performed such that the change is gentle, the number of bits of the change amount data can be set to a small constant value, so that communication data can be reduced only by using the increase / decrease code and change amount data. The effect of preventing the deterioration of the response accompanying the increase in the communication data amount is brought about.

The block diagram which shows the structure of the system by which the inductive load control apparatus of the Example of this invention is used. The timing chart showing the timing of the data used in the inductive load control apparatus of the Example of this invention. The code table showing the code | symbol included in command data in the inductive load control apparatus of the Example of this invention. Explanatory drawing which shows the example of the time change of the setting value of the drive current in the inductive load control apparatus of the Example of this invention. The table | surface which illustrates the aspect of the data reduction of each time in the setting example of the drive current in the inductive load control apparatus of the Example of this invention. Explanatory drawing which shows the structure of the transmission data in the inductive load control apparatus of the Example of this invention. The flowchart which shows the process which produces transmission data in the inductive load control apparatus of the Example of this invention. The flowchart which shows the process which sets the transmission data in the case of using an absolute value in the inductive load control apparatus of the Example of this invention. The flowchart which shows the process which sets the transmission data in case the 2's complement is used in the inductive load control apparatus of the Example of this invention. The flowchart which shows the process which receives data in the inductive load control apparatus of the Example of this invention, and determines a current setting value. The timing chart of the communication data in which a plurality of data is used continuously in the inductive load control device of the example of the present invention. The another timing chart of the communication data in which several data are used continuously in the inductive load control apparatus of the Example of this invention. The further another timing chart of the communication data in which several data are used continuously in the inductive load control apparatus of the Example of this invention. The timing chart of the communication data when not using an ENn signal in the inductive load control apparatus of the Example of this invention.

Explanation of symbols

100 System 9, 9 _{1 to} 9 _N Inductive Load 10 Inductive Load Control Device 12 Main Control Circuit 14 Communication Path 16, 16 _{1 to} 16 _N Sub Control Circuit

Claims (12)

An inductive load control device for controlling a current flowing through an inductive load element based on instruction data of an external host CPU and signals from various sensors,
A main control circuit for instructing a current setting value for a current flowing through the inductive load element based on the instruction data of the external host CPU and the sensor signal by a current setting signal;
A communication path for transmitting the current setting signal from the main control circuit;
A sub-control circuit that is connected to the communication path and the inductive load element and controls a current value to flow through the inductive load element based on the current setting signal from the main control circuit, and the current setting In the signal, a bit string of data representing the increase or decrease of the current set value is scanned from the MSB toward the LSB, and the bits up to the bit immediately preceding the bit in which the valid bit first appears in the scan are deleted from the bit string. An inductive load control device including change amount data that is data of the above and command data for instructing arithmetic processing of the change amount data. The change amount data is data of the remaining bits scanned from a bit string of data representing an absolute value of increase / decrease of a current set value, and deleted from the bit string based on the scan,
The command data includes an increase / decrease code indicating whether the current set value has increased or decreased from the previous current set value,
The sub control circuit receives the current setting signal, and selects whether to add or subtract the change amount data to the previous current setting value according to data in the command data in the current setting signal The inductive load control device according to claim 1, wherein the inductive load control device according to claim 1 is executed to obtain a new current set value and use the new current set value as data of the current set value. The change amount data is data of the remaining bits obtained by scanning a bit string of data in a two's complement format representing increase / decrease of the current set value and deleting from the bit string based on the scan,
The command data includes a code indicating that the variation data is data in a two's complement format,
The sub-control circuit receives the current setting signal, and when the data in the command data in the current setting signal indicates that the variation data is data in a two's complement format, The current set value data and the change amount data are calculated by an adder to obtain a new current set value, the new current set value is used as the current set value data, and the number of bits of the change amount data Is smaller than the number of input bits of the adder, the required bit number is added to the variation data as a higher-order bit of the most significant bit by adding a bit having the same value as the most significant bit of the variation data. The inductive load control device according to claim 1, wherein the number of bits of change amount data is made equal to the number of input bits of the adder. The main control circuit transmits the current setting signal by a plurality of channels divided in time in the current setting signal,
A plurality of inductive load elements are connected to the sub-control circuit, and the current setting signal for each inductive load element is received by each channel to control each inductive load element independently. The inductive load control device according to 1. The main control circuit instructs the operation on the first and second change amount data by the command data together with the first change amount data,
The current setting signal includes first change amount data transmitted in association with the command data, and second change amount data transmitted after the first change amount data,
2. The inductive load control device according to claim 1, wherein the sub-control circuit performs a calculation process based on the received command data on a calculation based on the first and second variation data. Using the main control circuit, the sub control circuit to which the inductive load element is connected, and the communication path connected to the main control circuit and the sub control circuit, the instruction data of the external host CPU and the signals from various sensors are used. A control method of an inductive load element that controls a current flowing through the inductive load element based on
The main control circuit scans a bit string of data representing increase / decrease in the current set value, which is the set value of the current flowing through the inductive load element, from the MSB toward the LSB, and the bit in which the effective bit first appears in the scan. A data generation step for generating change amount data that is data of the remaining bits obtained by deleting the bits up to the immediately preceding bit from the bit string, and command data for instructing arithmetic processing of the change amount data;
The main control circuit transmits a current setting signal including change amount data and command data through the communication path, and flows to the inductive load element based on the instruction data of the external host CPU and the sensor signal. Indicating a power setpoint current by the current setting signal;
A control step of controlling a current flowing through the inductive load element based on a current setting value of the current setting signal from the main control circuit by a sub control circuit that has received the current setting signal from the communication path. Inductive load control method. The data generation step includes
The main control circuit scanning a bit string of data representing an absolute value of increase / decrease of a current set value;
The main control circuit includes, as the change amount data, data of the remaining bits deleted from the bit string based on the scanning, and
The command data includes an increase / decrease code indicating whether the current set value has increased or decreased from the previous current set value,
In the control step, the sub control circuit that has received the current setting signal adds or subtracts the change amount data to the previous current setting value according to data in the command data in the current setting signal. The inductive load control method according to claim 6, wherein a new current set value is obtained by selectively executing whether the new current set value is used as data of the current set value. The data generation step includes
The main control circuit scanning a bit string of data in two's complement format representing an increase or decrease in a current set value;
The main control circuit includes, as the change amount data, data of the remaining bits deleted from the bit string based on the scanning, and
The command data includes a code indicating that the variation data is data in a two's complement format,
The control step receives the current setting signal when the data in the command data in the current setting signal indicates that the variation data is data in a two's complement format. A circuit calculates an immediately preceding current set value data and the change amount data by an adder to obtain a new current set value, which is used as the current set value data, and the change amount When the number of data bits is smaller than the number of input bits of the adder, the required number of bits is added to the change amount data as a higher order bit of the most significant bit with the same value as the most significant bit of the change amount data. The inductive load control method according to claim 6, wherein the step of making the number of bits of the variation data equal to the number of input bits of the adder. The data generation step is a step of generating change amount data and the command data to be transmitted by a plurality of channels divided in time by the main control circuit,
In the control step, the sub-control circuit to which a plurality of inductive load elements are connected receives the current setting signal for each inductive load element by each channel and controls each inductive load element independently. The inductive load control method according to claim 6. The command data is for instructing arithmetic processing of the first and second variation data,
The data generation step is a step of generating a first group of data including the first change amount data and the command data, and a second group of data including the second change amount data.
In the control step, the sub-control circuit that receives the first data group and the second data group performs a first current setting value based on the first variation data and the command data, The inductive load control method according to claim 6, wherein a current flowing through the inductive load element is controlled based on a change amount data of 2 and a second current setting value based on the command data. A plurality of inductive load elements are connected to the sub-control circuit,
The communication path performs communication of a plurality of channels divided in time,
The inductive load control method according to claim 6, wherein the sub control circuit receives a current setting signal for each inductive load element by each channel and controls each inductive load element independently. Based on the instruction data of the external host CPU and signals from various sensors using the main control circuit, the sub control circuit to which the inductive load element is connected, and the communication path connected to the main control circuit and the sub control circuit An inductive load control program for controlling the current flowing through the inductive load element,
The main control circuit, a set value of the current flowing through the inductive load element scanned from MSB bit string of data representing the increase or decrease of the current set value toward the LSB, of the first valid bit appears bit in the scanning A data generation step for generating change amount data that is data of the remaining bits obtained by deleting the bits up to the immediately preceding bit from the bit string , and command data for instructing arithmetic processing of the change amount data;
By transmitting a current setting signal including change amount data and command data to the main control circuit through the communication path, it should flow to the inductive load element based on the instruction data of the external host CPU and the sensor signal. Indicating a setpoint current by means of the current setting signal;
A control step for controlling a current flowing through the inductive load element based on a current setting value of the current setting signal from the main control circuit to the sub control circuit that has received the current setting signal from the communication path. An inductive load control program.

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