JP4762219B2 - Control device for mechanical system - Google Patents

Description

  The present invention relates to a control device for a mechanical system having a function for determining, for each operation, an acceleration / deceleration parameter for performing the shortest operation within a range that satisfies the constraints of a transmission mechanism such as a motor and a reducer of each axis. is there.

  A conventional mechanical system control device will be described (for example, see Patent Document 1). First, the maximum speed that each axis can output is calculated when the axes of the mechanical system simultaneously start and end simultaneously. Next, initial values of acceleration time and deceleration time when the speed of each axis is operated in a speed command pattern for accelerating / decelerating in a trapezoidal shape are set. Start position, end point of the operation, calculated acceleration time, deceleration time, calculate the position and speed of each axis of acceleration start point, acceleration end point, deceleration start point, deceleration end point from the maximum speed, calculated position, Using the speed, the acceleration time t1a that is the shortest in a range that satisfies the constraints such as the maximum allowable torque of the motor and the transmission mechanism at the acceleration start point, and the maximum allowable torque of the motor and the transmission mechanism at the acceleration end point An acceleration time t1b that is the shortest within the range to be satisfied is calculated, and the larger one is set as the acceleration time t1. Similarly, using the calculated position and speed, the deceleration time t2a that is the shortest within a range that satisfies the constraints such as the maximum allowable torque of the motor and the transmission mechanism at the deceleration start point, and the allowance of the motor and the transmission mechanism at the deceleration end point. The deceleration time t2b that is the shortest within a range that satisfies the constraints such as the maximum torque value is calculated, and the larger one is set as the deceleration time t2. From the calculated acceleration time t1, deceleration time t2 and start point, end point, maximum speed, calculate the position and speed of each axis of acceleration start point, acceleration end point, deceleration start point, deceleration end point, and again, acceleration time Calculate the deceleration time. The above repetition is executed a specified number of times.

Japanese Patent Application Laid-Open No. 07-200033 (Examples 3, 4 and 4)

  In the conventional mechanical system control device as described above, when the allowable torque of the motor decreases in the high speed range, it is necessary to reduce the acceleration even in the low speed range in accordance with the high speed range. There was a problem that could not be achieved. Further, there is a problem that the operating time may be longer because the acceleration decreases when the maximum speed is increased.

  The present invention has been made to solve the above-described problems, and its purpose is to operate at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range. Acceleration / deceleration is not required to be reduced more than necessary in the low speed range, and the operating time can be shortened. In addition, the maximum speed can be increased to prevent the operating time from increasing. It is possible to obtain a control device for a mechanical system in which a threshold value can be set.

The control device of the mechanical system according to the present invention calculates the torque of each axis of the mechanical system using the position, speed, and acceleration of each axis, and the dynamic characteristic of the mechanical system at a representative point in the low speed region on the time-speed coordinate. Low-speed acceleration / deceleration time calculation means for calculating the minimum acceleration time and deceleration time in a range that satisfies the allowable torque determined from the drive mechanism constituted by the motor and transmission mechanism of each axis based on the first equation of motion And a second equation of motion that expresses the dynamic characteristics of the mechanical system at a representative point in the high-speed region on the time-speed coordinates , by calculating the torque of each axis of the mechanical system using the position, velocity, and acceleration of each axis. fast and calculates the minimum acceleration time and deceleration time range satisfying the permissible torque determined from the configured drive mechanism by a motor and transmission mechanism of each axis based on Acceleration / deceleration time calculation means, low-speed area acceleration time and deceleration time calculated by the low-speed area acceleration / deceleration time calculation means, and high-speed area acceleration time and deceleration time calculated by the high-speed area acceleration / deceleration time calculation means Based on this, command generation means for generating speed command patterns of different acceleration / deceleration in the low speed range and the high speed range is provided.

  The mechanical system control device according to the present invention calculates the minimum acceleration time and deceleration time in consideration of both the dynamic characteristics of the mechanical system and the output limit value of the drive mechanism in each of the low speed range and the high speed range. In a mechanical system where the limit value of the output of the drive mechanism is different between the low speed range and the high speed range and the acceleration / deceleration that can be generated by the displacement of each axis is different, the output limits of the low speed range and the high speed range are satisfied for each operation. However, there is an effect that it can be operated in a short time.

Embodiment 1 FIG.
A control device for a mechanical system according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a block diagram showing the configuration of a control device for a mechanical system according to Embodiment 1 of the present invention. In the following, in each figure, the same reference numerals indicate the same or corresponding parts.

  In FIG. 1, a control device for a mechanical system according to Embodiment 1 of the present invention includes a maximum speed calculation means 1 for calculating a maximum speed, and a threshold value calculation means 2 for calculating a threshold value that defines a boundary between a low speed range and a high speed range. , A low speed range acceleration / deceleration time calculation means 3 for calculating acceleration time and deceleration time in the low speed range, a threshold value correction means 4 for correcting the threshold value, and a high speed range acceleration / deceleration time calculation means for calculating the acceleration time and deceleration time in the high speed range 5, a command generation unit 6 that generates a speed command pattern, and a motor control unit 7 that controls a motor that drives each axis of a mechanical system 8 such as a robot. The drive mechanism according to the present invention includes a motor for each axis and a transmission mechanism.

  Next, the operation of the control device for the mechanical system according to the first embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing the operation of the control device for the mechanical system according to Embodiment 1 of the present invention.

  First, the maximum speed calculation means 1 reads the information of the operation start point and the operation end point of the operation for each operation command by the operation program, and the maximum speed (acceleration / deceleration) that each axis of the mechanical system 8 can output in the operation. The speed of each axis when the time is 0 is calculated.

  When the number of axes of the mechanical system 8 is n (natural number) and all the axes start to operate at the same time in each operation and end the operation at the same time, the allowable maximum speed of the i-th axis is vmaxi and the i-th axis operation start point Assuming that the value of i is spi and the value of the motion end point of the i-th axis is epi, the maximum speed vi that each axis can output can be calculated by the following equations (1) and (2). Here, abs () means an absolute value, and max () means a maximum value.

  maxdl = max (abs (ep1-sp1) / vmax1, abs (ep2-sp2) / vmax2,... abs (epn-spn) / vmaxn) (1)

  vi = abs (epi-spi) / maxdl (2)

  FIG. 3 is a diagram showing speed-torque characteristics of a motor that is a control target of the control device of the mechanical system according to Embodiment 1 of the present invention. FIG. 4 is a diagram showing a speed command pattern in the low speed range of the control device for the mechanical system according to the first embodiment of the present invention.

  Next, the threshold value calculation means 2 calculates the threshold value minr for the low speed range and the high speed range according to the following procedure (step 101). First, as shown in FIG. 3, in the speed-torque characteristics of the i-axis motor, it is assumed that the torque that can be generated is reduced in the region of the speed vai or higher. At this time, the intermediate variable ri of each axis is obtained by the following equation (3), and the minimum value of the intermediate variable ri of each axis shown by the following equation (4) is set as the threshold value minr of the low speed region and the high speed region. However, if the intermediate variable ri> 1, the intermediate variable ri = 1.

  ri = vai / vi (3)

  minr = min (r1, r2,..., rn) (4)

  Thus, by setting the threshold value minr according to the operation, it is possible to extend the section (low speed region) where acceleration / deceleration can be increased according to the operation, and there is an effect that the operation time can be shortened.

  Next, the low speed region acceleration / deceleration time calculation means 3 calculates the acceleration / deceleration time in the low speed region by setting the region where the speed of each axis is equal to or less than minr * vi as the low speed region (steps 102 to 104). Further, the high-speed area acceleration / deceleration time calculation means 5 calculates the acceleration / deceleration time in the high-speed area by setting the area where the speed of each axis is larger than minr * vi as the high-speed area (steps 106 to 108). Further, the command generation means 6 generates an acceleration / deceleration speed command pattern based on the acceleration / deceleration time calculated by the low-speed area acceleration / deceleration time calculation means 3 with the speed of each axis as the low speed range of minr * vi or less. Then, an acceleration / deceleration speed command pattern based on the acceleration / deceleration time calculated by the high-speed area acceleration / deceleration time calculation means 5 is generated by setting an area where the speed of each axis is larger than minr * vi as a high-speed area. The motor control means 7 controls the acceleration / deceleration of the motor based on the speed command patterns in the low speed range and the high speed range.

  The low-speed area acceleration / deceleration time calculation means 3 performs the motor and transmission of each axis when operating with the trapezoidal speed command pattern as shown in FIG. 4 as the maximum speed vli of each axis shown by the following equation (5). The shortest acceleration time and deceleration time are calculated within the range that satisfies the allowable torque limit of the mechanism.

  vli = minr * (epi-spi) / maxdl (5)

  Here, the acceleration time and the deceleration time are the time required for acceleration and deceleration when accelerating at a constant acceleration up to the maximum speed vmi including the high speed range, as shown by the following equation (6), even in the low speed range. To do.

  vmi = (epi-spi) / maxdl (6)

  First, initial values of acceleration time and deceleration time are set. Next, from the initial values of the set acceleration time and deceleration time, the maximum speed vli in the low speed region of each axis, the maximum speed vmi including the high speed region, the operation start point, and the operation end point data, As shown in FIG. 4, the position and speed of each axis at four representative points of “acceleration start point”, “acceleration end point”, “deceleration start point”, and “deceleration end point” are calculated. The acceleration time t1a at the acceleration start point is calculated using the equation of motion of the mechanical system 8 from the calculated position and speed of the acceleration start point and the limit values of the allowable torque of the motor and transmission mechanism of each axis. Similarly, the acceleration time t1b at the acceleration end point is calculated using the equation of motion of the mechanical system 8 from the calculated position and speed of the acceleration end point and the limit value of the allowable torque of the motor and transmission mechanism of each axis. The calculated acceleration time t1a and acceleration time t1b are compared, and the larger one is set as the acceleration time t1.

  The acceleration time t1a at the “acceleration start point” is calculated as follows. First, it is assumed that the equation of motion of the mechanical system 8 can be expressed by the following equation (7). Here, M is an inertia matrix, a is a vector composed of acceleration of each axis, h is centrifugal / Coriolis force of each axis, g is gravity of each axis, and f is friction force of each axis.

  τ = Ma + h + g + f (7)

  At this time, M, h, g, and f are functions of a vector p constituted by the position of each axis and a vector v constituted by the velocity of each axis, respectively, and M (p), h (p, v) , G (p), f (v). The vector composed of the position of each axis at the acceleration start point is p1a, the vector composed of the speed of each axis at the acceleration start point is v1a, the vector composed of the maximum speed vli in the low speed region of each axis is vl, and the high speed If the vector composed of the maximum speed vmi including the region is vm, the equation of motion when the acceleration time is kt is the following equation (8).

τ = M (p1a) vm / kt + h (p1a, v1a) + g (p1a) + f (v1a)
(8)

  Therefore, when the i-th element of M (p1a) vm is mvi and the allowable torque determined from the motor and transmission mechanism of each axis is τmaxi, kti satisfying the following equation (9) is obtained. Is the shortest acceleration time t1ai within the range satisfying the allowable torque determined from.

τmaxi = mvi / kti + hi + gi + fi (when mvi> 0),
-Τmaxi = mvi / kti + hi + gi + fi (when mvi <0)
(9)

  Here, hi, gi, and fi are the i-th elements of h (p1a, v1a), g (p1a), and f (v1a), respectively. When the allowable torque determined from the motor and the transmission mechanism is determined by the motor, the allowable torque τmax1i at the speed 0 is used as τmaxi in the equation (9) at the acceleration start point. The maximum value of the acceleration time t1ai for each axis is assumed to be t1a.

  Similarly, for the acceleration time t1b at the “acceleration end point”, the equation of motion when the acceleration time is kt from the position p1b of the acceleration end point and the speed v1b of the acceleration end point is the following equation (10).

τ = M (p1b) vm / kt + h (p1b, v1b) + g (p1b) + f (v1b)
(10)

  Therefore, when the i-th element of M (p1b) vm is mvbi and the allowable torque determined from the motor and transmission mechanism of each axis is τmaxi, kti satisfying the following expression (11) is obtained. The shortest acceleration time t1bi within a range satisfying the allowable torque determined from The maximum value of the acceleration time t1bi of each axis is assumed to be t1b.

τmaxi = mvbi / kti + hbi + gbi + fbi (when mvbi> 0),
−τmaxi = mvbi / kti + hbi + gbi + fbi (when mvbi <0) (11)

  Here, hbi, gbi, and fbi are i-th elements of h (p1b, v1b), g (p1b), and f (v1b), respectively. When the allowable torque determined by the motor and the transmission mechanism is determined by the motor, the allowable torque τmaxbi at the speed vli is used as τmaxi in the equation (11) at the acceleration end point. When minr used in Equation (5) is an initial value, τmaxbi is the same as the allowable torque τmax1i at speed 0. The larger of the acceleration times t1a and t1b is set as the acceleration time t1 in the low speed region in the current repetition cycle.

  The deceleration time t2a at the “deceleration start point” is calculated according to the following procedure. First, the equation of motion when the deceleration time is gt from the position p2a at the deceleration start point and the speed v2a at the deceleration start point is the following equation (12).

τ = −M (p2a) vm / gt + h (p2a, v2a) + g (p2a) + f (v2a)
(12)

  Therefore, when the i-th element of M (p2a) vm is mv2ai and the allowable torque determined from the motor and transmission mechanism of each axis is τmaxi, gti satisfying the following equation (13) is the i-axis motor and transmission mechanism. Is the shortest deceleration time t2ai within a range satisfying the allowable torque determined from. The maximum value of the deceleration time t2ai for each axis is assumed to be t2a.

τmaxi = −mv2ai / gti + h2ai + g2ai + f2ai (when mv2ai <0),
−τmaxi = −mv2ai / gti + h2ai + g2ai + f2ai (when mv2ai> 0) (13)

  Here, h2ai, g2ai, and f2ai are the i-th elements of h (p2a, v2a), g (p2a), and f (v2a), respectively. When the allowable torque determined from the motor and the transmission mechanism is determined by the motor, the allowable torque τmax2ai at the speed vli is used as τmaxi in the equation (13) at the deceleration start point. When minr used in Equation (5) is an initial value, τmax2ai is the same as the allowable torque τmax1i at speed 0.

  The deceleration time t2b at the “deceleration end point” is calculated according to the following procedure. First, the equation of motion when the deceleration time is gt from the position p2b at the deceleration end point and the speed v2b at the deceleration start point is the following equation (14).

τ = −M (p2b) vm / gt + h (p2b, v2b) + g (p2b) + f (v2b)
(14)

  Accordingly, when the i-th element of M (p2b) vm is mv2bi and the allowable torque determined from the motor and transmission mechanism of each axis is τmaxi, gti satisfying the following equation (15) is the i-th axis motor and transmission mechanism. Is the shortest deceleration time t2bi within the range satisfying the allowable torque determined from. Let t2b be the maximum value of the deceleration time t2bi of each axis.

τmaxi = −mv2bi / gti + h2bi + g2bi + f2bi (when mv2bi <0),
−τmaxi = −mv2bi / gti + h2bi + g2bi + f2bi (when mv2bi> 0) (15)

  Here, h2bi, g2bi, and f2bi are i-th elements of h (p2b, v2b), g (p2b), and f (v2b), respectively. When the allowable torque determined from the motor and the transmission mechanism is determined by the motor, the allowable torque τmaxli at the speed 0 is used as τmaxi in the equation (15) at the deceleration end point. The larger one of the deceleration times t2a and t2b is set as the deceleration time t2 in the low speed region of the current repetition cycle.

  Next, the threshold value correcting means 4 calculates the threshold value minr in the next iteration according to the following procedure (step 105). First, for each axis, the use torque τki at the acceleration end point and the use torque τgi at the deceleration start point are calculated by the following equations (16) and (17), respectively, and the larger of the use torques τki and τgi The use torque usage rate τsi of the i-axis is assumed.

τki = abs (mvbi / t1 + hbi + gbi + fbi) (16)
τgi = abs (−mv2ai / t2 + h2ai + g2ai + f2ai) (17)

  FIG. 5 is a diagram for explaining a calculation method of a threshold correction value in the control device for a mechanical system according to the first embodiment of the present invention. FIG. 6 is a diagram showing speed command patterns in the low speed range and the high speed range of the control device for the mechanical system according to the first embodiment of the present invention.

  Next, as shown in FIG. 5, the speed v2i at the intersection of the speed-torque characteristic (broken line) and the straight line τ = τsi is calculated for each axis. Here, when the use torque usage rate τsi matches the allowable torque τmaxli, the speed v2i is set as a break point vai of the speed-torque characteristic. Further, when the calculated speed v2i is larger than the maximum speed vi, the speed v2i is set as the maximum speed vi. From the calculated velocity v2i of each axis, the following equation (18) is calculated, and the minimum value of the intermediate variable r2i is set as the correction value of the threshold value minr, and the threshold value of the low speed range and the high speed range in the next iteration.

  r2i = v2i / vi (18)

  In this way, by correcting the range of the low speed range according to the operation, that is, the threshold value, it is possible to extend the section in which the acceleration / deceleration can be increased according to the operation, and the operation time can be shortened.

  In the second and subsequent iterations, the corrected threshold value minr and the acceleration time and deceleration time of the previous cycle are used to recalculate the acceleration end point and deceleration start point in the low speed range. The calculation of (13) is performed, and the acceleration time t1b and the deceleration time t2a at the acceleration end point and the deceleration start point are obtained again. The larger of the acceleration times t1a and t1b is set as the acceleration time t1 in the low speed region in the current repetition cycle. Further, the larger one of the deceleration times t2a and t2b is set as the deceleration time t2 in the low speed region in the current repetition cycle.

  When the specified number of times is n, correction of the threshold value minr by the threshold value correction means 4 is repeated n-1 times, and calculation of the acceleration time t1 and the deceleration time t2 in the low speed region acceleration / deceleration time calculation means 3 is repeated n times. The calculation of the threshold value minr, acceleration time t1, and deceleration time t2 in the region is terminated, and the process proceeds to the high-speed region acceleration / deceleration time calculation means 5.

  Further, the acceleration time t1 and deceleration time t2 calculated in the n-th iteration and the threshold value minr calculated in the (n-1) -th iteration are used as the acceleration time t1, the deceleration time t2 and the threshold minr in the low-speed region, and the high-speed region acceleration / deceleration time. It outputs to the calculation means 5 and the command generation means 6.

  Next, the high-speed region acceleration / deceleration time calculation means 5 has four representatives of “high-speed region start point”, “high-speed region acceleration end point”, “high-speed region deceleration start point”, and “high-speed region end point” shown in FIG. At the point, the equation of motion of the mechanical system 8 is calculated, and acceleration times t3a and t3b in the high speed region and deceleration times t4a and t4b in the high speed region are calculated.

  First, the initial values of the acceleration time and deceleration time in the high speed region are set as the acceleration time t1 in the low speed region and the deceleration time t2 in the low speed region, respectively, the position p3b of each axis at the end of the high speed region acceleration, the speed v3b of each axis, The position p4a of each axis and the speed v4a of each axis at the high speed region deceleration start point are calculated.

  Further, the position and speed of the high speed region start point are the same as the position p1b and the speed v1b at the acceleration end point in the last repetition by the low speed region acceleration / deceleration time calculation means 3. Further, the position and speed at the high speed region end point are the same as the position p2a and the speed v2a at the deceleration start point in the last repetition by the low speed region acceleration / deceleration time calculation means 3.

  Since the equation of motion of the “starting point of the high speed region” is Equation (10), kti satisfying Equation (11) is the shortest acceleration time t3ai within the range satisfying the allowable torque determined from the i-axis motor and transmission mechanism. is there. However, the difference from the calculation in the low speed range is that when the allowable torque determined from the motor and the transmission mechanism is determined by the motor, the allowable torque at v3bi which is the i-th axis element of the speed v3b at the high speed range acceleration end point as the allowable torque τmaxi. Calculation is performed using τmax3bi. The maximum value of the calculated acceleration time t3ai is defined as the acceleration time t3a.

  Since the equation of motion of the “high-speed end point” is expressed by equation (12), gti that satisfies equation (13) satisfies the allowable torque determined from the i-axis motor and transmission mechanism, with the shortest deceleration time t4bi. is there. However, the difference from the calculation in the low speed range is that when the allowable torque determined from the motor and the transmission mechanism is determined by the motor, the allowable torque at v4ai that is the i-th axis element of the speed v4a at the high speed range deceleration start point as the allowable torque τmaxi. It calculates using (tau) max4ai. The maximum value of the calculated deceleration time t4bi is set as the deceleration time t4b.

  That is, the high-speed area acceleration / deceleration time calculation means 5 performs at least one calculation of the equation of motion expressing the dynamic characteristics of the mechanical system at a representative point in the high-speed area, and represents the low-speed area acceleration by the low-speed area acceleration / deceleration time calculation means 3. By using the calculation result of the equation of motion expressing the dynamic characteristic of the mechanical system in terms of points, the number of calculations of the equation of motion expressing the dynamic characteristic of the mechanical system can be reduced, and the amount of calculation can be reduced.

  The equation of motion of the “high-speed region acceleration end point” is expressed by the following equation (19).

τ = M (p3b) vm / kt + h (p3b, v3b) + g (p3b) + f (v3b)
(19)

  Therefore, if the i-th element of M (p3b) vm is mv3bi and the allowable torque determined from the motor and transmission mechanism of each axis is τmaxi, kti satisfying the following equation (20) is obtained. Is the shortest acceleration time t3bi within the range satisfying the allowable torque determined from. The maximum value of the acceleration time t3bi of each axis is defined as the acceleration time t3b.

τmaxi = mv3bi / kti + h3bi + g3bi + f3bi (when mv3bi> 0),
−τmaxi = mv3bi / kti + h3bi + g3bi + f3bi (when mv3bi <0) (20)

  Here, h3bi, g3bi, and f3bi are i-th elements of h (p3b, v3b), g (p3b), and f (v3b), respectively. Further, when the allowable torque determined from the motor and the transmission mechanism is determined by the motor, the allowable torque τmax3bi at v3bi that is the i-th axis element of the speed v3b at the high speed region acceleration end point is used as the allowable torque τmaxi.

  The equation of motion of the “high-speed region deceleration start point” is the following equation (21).

τ = −M (p4a) vm / kt + h (p4a, v4a) + g (p4a) + f (v4a)
(21)

  Accordingly, when the i-th element of M (p4a) vm is mv4ai and the allowable torque determined from the motor and transmission mechanism of each axis is τmaxi, gti satisfying the following equation (22) is the i-axis motor and transmission mechanism. Is the shortest deceleration time t4ai within the range satisfying the allowable torque determined from. The maximum value of the deceleration time t4ai for each axis is defined as a deceleration time t4a.

τmaxi = −mv4ai / gti + h4ai + g4ai + f4ai (when mv4ai> 0),
−τmaxi = −mv4ai / gti + h4ai + g4ai + f4ai (when mv4ai <0) (22)

  Here, h4ai, g4ai, and f4ai are the i-th elements of h (p4a, v4a), g (p4a), and f (v4a), respectively. Further, when the allowable torque determined by the motor and the transmission mechanism is determined by the motor, the allowable torque τmax4ai at v4ai that is the i-th axis element of the speed v4a at the high-speed region deceleration start point is used as the allowable torque τmaxi.

  The larger acceleration time t3a, t3b is the acceleration time t3 in the high speed range, and the longer acceleration time t4a, t4b is the deceleration time t4 in the high speed range. The acceleration time and deceleration time in the high speed range are also calculated m (natural number), which is the specified number of repetitions. In the k-th iteration, the position and speed of the high-speed region start point, high-speed region acceleration end point, high-speed region deceleration start point, high-speed region end point are calculated using the acceleration time and deceleration time in the high-speed region in the previous iteration, The acceleration times t3a and t3b and the deceleration times t4a and t4b are calculated again, and the larger acceleration time t3a and t3b is set as the acceleration time t3 in the high speed region, and the larger deceleration time t4a and t4b is the deceleration time t4 in the high speed region. And The calculated acceleration time t3 and deceleration time t4 are output to the command generation means 6.

  Note that the number of repetitions may be one in both the low speed range and the high speed range. Further, acceleration and deceleration may be calculated instead of acceleration time and deceleration time.

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing. Furthermore, there is an effect that threshold values for the low speed range and the high speed range can be set according to each operation.

Embodiment 2. FIG.
A control device for a mechanical system according to Embodiment 2 of the present invention will be described.

  In the first embodiment, the position of the high-speed region start point is the same as the position of the acceleration end point used in the final iteration calculation by the low-speed region acceleration / deceleration time calculation means 3, but in this second embodiment, In the last iteration by the low speed region acceleration / deceleration time calculation means 3, the acceleration end point is re-determined using the acceleration time t1 and the deceleration time t2, and the position of the re-determined acceleration end point is set as the position of the high speed region start point.

  In the first embodiment, the position of the high speed region end point is the same as the position of the deceleration start point used in the final iteration calculation by the low speed region acceleration / deceleration time calculation means 3. Then, in the last iteration by the low-speed area acceleration / deceleration time calculation means 3, the deceleration start point is re-determined using the acceleration time t1 and the deceleration time t2, and the position of the re-determined deceleration start point is set as the position of the high-speed area end point. To do.

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing. Furthermore, there is an effect that threshold values for the low speed range and the high speed range can be set according to each operation.

Embodiment 3 FIG.
A mechanical system control apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 7 is a diagram for explaining a method of calculating a threshold correction value in the control device for a mechanical system according to Embodiment 3 of the present invention.

  Since the difference from the first embodiment described above is the processing content of the threshold value correcting means 4, only the processing content of the threshold value correcting means 4 will be described. In the first embodiment, as shown in FIG. 5, the intersection between the speed-torque characteristic (polygonal line) and the straight line τ = τsi is obtained. However, in the third embodiment, as shown in FIG. The intersection of the speed-torque characteristic (broken line) C2 (solid line) obtained by subtracting the viscous friction force from the torque characteristic (broken line) C1 (broken line) and the straight line τ = τsi is obtained.

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing. Furthermore, there is an effect that threshold values for the low speed range and the high speed range can be set according to each operation.

Embodiment 4 FIG.
A control device for a mechanical system according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of the control device of the mechanical system according to Embodiment 4 of the present invention.

  The difference from the first embodiment is that there is no threshold correction means 4. In each repetition, the low speed region acceleration / deceleration time calculation means 3 uses the threshold value minr calculated by the threshold value calculation means 2 without modification.

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing. Furthermore, there is an effect that threshold values for the low speed range and the high speed range can be set according to each operation.

Embodiment 5 FIG.
A control device for a mechanical system according to Embodiment 5 of the present invention will be described with reference to FIG. FIG. 9 is a block diagram showing a configuration of a control device for a mechanical system according to Embodiment 5 of the present invention.

  The difference from the fourth embodiment is that there is no threshold value calculation means 2. In the fifth embodiment, the minimum value of vai / vmaxi of each axis is stored as a threshold value minr in advance in a memory (not shown), and the stored threshold value minr is stored in the low speed region acceleration / deceleration time calculation means 3 and the high speed region acceleration / deceleration time. Used by the calculation means 5 and the command generation means 6.

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing.

Embodiment 6 FIG.
A control device for a mechanical system according to Embodiment 6 of the present invention will be described.

  In the above-described first embodiment, the low-speed region acceleration / deceleration time calculation means 3 employs the larger acceleration time t1a, t1b as the acceleration time t1 in each iteration, but in this sixth embodiment, in the kth iteration The acceleration time t1b is set to t1b (k), and the acceleration time t1 in the low speed region is calculated in the k-th iteration by the following equation (23).

t1 = max (t1a, t1b (1), t1b (2),... t1b (k))
(23)

  Similarly, the deceleration time t2a in the kth iteration is set to t2a (k), and the deceleration time t2 in the low speed region in the kth iteration is calculated by the following equation (24).

t2 = max (t2b, t2a (1), t2a (2),... t2a (k))
(24)

  Further, the acceleration time t3 and the deceleration time t4 in the high speed region are calculated by the following equations (25) and (26).

  t3 = max (t3a (1), t3a (2),... t3a (k), t3b (1), t3b (2),... t3b (k)) (25)

  t4 = max (t4a (1), t4a (2),... t4a (k), t4b (1), t4b (2),... t4b (k)) (26)

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing. Furthermore, there is an effect that threshold values for the low speed range and the high speed range can be set according to each operation.

Embodiment 7 FIG.
A control device for a mechanical system according to Embodiment 7 of the present invention will be described.

  In the first embodiment, the low speed region acceleration / deceleration time calculation means 3 calculates the acceleration time t1 in the low speed region from the acceleration start point and the acceleration end point in each iteration. However, in this seventh embodiment, the acceleration start time The acceleration time t1 in the low speed region is calculated from the point, the acceleration end point, and the middle point (middle point on the time axis) of the low speed region.

  Similarly, in the seventh embodiment, the deceleration time t2 in the low speed region is calculated from the deceleration start point, the deceleration end point, and the midpoint of the deceleration region in the low speed region.

  Further, in the seventh embodiment, the high-speed region acceleration / deceleration time calculation means 5 repeats the high-speed region acceleration time t3 from the high-speed region start point, the high-speed region acceleration end point, and the midpoint of the high-speed region acceleration section. And the deceleration time t4 in the high speed range is calculated from the end point of the high speed range, the start point of deceleration in the high speed range, and the midpoint of the deceleration range in the high speed range.

  Since the operation can be performed at the highest possible acceleration / deceleration within the range satisfying the limitations of the motor and the transmission mechanism independently in the low speed range and the high speed range, it is not necessary to reduce the acceleration / deceleration more than necessary in the low speed range, and the operation time can be shortened. In addition, since the maximum speed is increased, there is an effect that it is possible to prevent the operating time from increasing. Furthermore, there is an effect that threshold values for the low speed range and the high speed range can be set according to each operation.

It is a block diagram which shows the structure of the control apparatus of the mechanical system which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the control apparatus of the mechanical system which concerns on Embodiment 1 of this invention. It is a figure which shows the speed-torque characteristic of the motor which is a control object of the control apparatus of the mechanical system which concerns on Embodiment 1 of this invention. It is a figure which shows the speed command pattern of the low speed area of the control apparatus of the mechanical system which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the calculation method of the correction value of the threshold value in the control apparatus of the mechanical system which concerns on Embodiment 1 of this invention. It is a figure which shows the speed command pattern of the low speed area of the control apparatus of the mechanical system which concerns on Embodiment 1 of this invention, and a high speed area. It is a figure for demonstrating the calculation method of the correction value of the threshold value in the control apparatus of the mechanical system which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the control apparatus of the mechanical system which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structure of the control apparatus of the mechanical system which concerns on Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Maximum speed calculating means, 2 Threshold calculating means, 3 Low speed area acceleration / deceleration time calculating means, 4 Threshold correction means, 5 High speed area acceleration / deceleration time calculating means, 6 Command generation means, 7 Motor control means, 8 Mechanical system.

Claims (4)

The torque of each axis of the mechanical system is calculated using the position, speed, and acceleration of each axis, and based on the first equation of motion that expresses the dynamic characteristics of the mechanical system at the representative point in the low speed region on the time-speed coordinate. Low-speed acceleration / deceleration time calculating means for calculating the minimum acceleration time and deceleration time within a range that satisfies the allowable torque determined from the drive mechanism constituted by the motor and transmission mechanism of each axis ;
Based on the second equation of motion that calculates the torque of each axis of the mechanical system using the position, velocity, and acceleration of each axis, and expresses the dynamic characteristics of the mechanical system at the representative point in the high speed region on the time-speed coordinate. High-speed acceleration / deceleration time calculating means for calculating the minimum acceleration time and deceleration time within a range that satisfies the allowable torque determined from the drive mechanism constituted by the motor and transmission mechanism of each axis ;
The low speed range and the high speed range are calculated based on the low speed range acceleration time and deceleration time calculated by the low speed range acceleration / deceleration time calculation unit and the high speed range acceleration time and deceleration time calculated by the high speed range acceleration / deceleration time calculation unit. And a command generating means for generating a speed command pattern having different acceleration / deceleration in each region. The high speed region acceleration / deceleration time calculation means performs at least one of the calculation of the high speed region start point and the high speed region end point of the second equation of motion by the low speed region acceleration / deceleration time calculation unit. The control apparatus for a mechanical system according to claim 1, wherein the control is performed using the calculation result. Based on the speed-output characteristics of the drive mechanism and the maximum speed that the drive mechanism can output in the operation, threshold values for the low speed range and the high speed range when generating speed command patterns of different acceleration / deceleration in the low speed range and the high speed range are set. The control device for a mechanical system according to claim 1 or 2, further comprising threshold value calculation means for calculating. Each axis torque when the acceleration / deceleration time calculated based on the calculation result of the first equation of motion is used is calculated, and the broken line of the speed-torque characteristic is corrected based on each calculated axis torque. The mechanical system control device according to claim 3, further comprising threshold value correcting means for correcting the threshold value based on a broken line .

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