Analysis of Innovative Design of Energy Efficient Hydraulic Actuators
High speed complementary metal oxide semiconductor CMOS technology, combined with monolithic transformer technology, means the on-chip isolation provides outstanding performance characteristics, superior to alternatives such as optocoupler devices.
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products. The FlexMC Kit TM enables you to accelerate time-to-market and increase performance with powerful model-based design tools.
Solution Overview The FlexMC Kit has the hardware and software required to spin the motor under open or closed loop speed control. BE assumes all responsibility for the proper installation and operation of the kit.
This solution combines hardware and software with out-of-the-box functionality for a permanent magnet synchronous motor PMSM with hall sensor, encoder, or sensorless feedback. NET-based graphical user interface GUI is provided to enable motor start-stop, speed control, and data visualization.
The FlexMC Kit hardware comes in two variants. The board-only option includes the motor drive board only. In this case users can connect their own motor and power source. Flexible evaluation of ADI isolation technology in a highly configurable system-oriented platform is enabled with multiple test-points, and connectivity options.
The benefits of ADI isolated sigma-delta converters for voltage and current measurement, isolated gate drivers, and power controllers can be explored in a full system application at dc bus levels up to V. There are 2 models available, isolated inverter platform, and isolated inverter platform with full featured IGBT drivers. Solution Overview The isolated inverter platform and isolated inverter platform with full featured IGBT drivers offer a power board that runs from a dc input and provides a three-phase variable frequency, variable voltage, and variable dead-time PWM output to a three-phase motor or load.
The inverter is provided as an open loop platform, but feedback signals are provided to enable the application developer to close the control loop. For the isolated inverter platform EV-MCS-ISOINV-Z , two isolated current,phase to phase and dc bus voltage feedback signals are provided to the control side of the board via sigma-delta modulators, and these can be used for development of control algorithms. For both platforms, a DC — rather than AC- input is provided to allow flexibility on the dc bus voltage level rather than it being limited to the ac line peak.
The board is designed to work from a DC supply in the range 24VdcVdc.. The power board is rated up to 2kVA without forced air cooling. Additional power throughput can be achieved with fan cooling added.
A series connected diode implements a half-wave rectifier at the input, so if needed, the power board can be driven from an AC supply.
However output power is limited in this case. Two motors can be driven at the same time, each motor having its separate power supply. The kit consists of two boards: Information on the FMC board, and how to use it, the design package that surrounds it, and the software which can make it work, can be found by clicking the software link. Configure operating conditions such as input tones and external jitter, as well as device features like gain or digital down-conversion.
Performance characteristics include noise, distortion, and resolution, FFTs, timing diagrams, response plots, and more. ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.
International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. State variable analysis and design. This course is dually listed with an equivalent graduate level course EE and requires a minimum GPA of 2. Simulation and modeling; introduction to linear systems theory; concepts of controllability and observability; specifications; structures and limitations; review of classical design methods; state feedback design methods; multivariable control; robust stability and sampled data implementation.
This course is dually listed with an equivalent graduate-level course EE and requires a minimum G. State space description; methods of linearization; isoclines; stability of nonlinear systems; Lyapunov's direct method; harmonic linearization; describing functions; dual input describing functions; Popov's method; circle criterion and computer aided analysis.
This graduate-level course is dually listed with an equivalent course EE and requires a minimum GPA of 2. PLC overview; ladder logic; programming of timers and counters; programming control; data manipulation and math; instructions; sequencers and shift register instructions; data acquisition methods.
State space and transfer function description of discrete-time systems; solution of discrete state equation; discrete-time model of analog plants; frequency domain analysis; design of discrete state-feedback regulators; observers and tracking systems. Characteristics of power devices; physics of transport phenomena; breakdown voltage; power rectifiers; bipolar transistors; power MOSFET; insulated-gate bipolar transistor and MOS-gated thyristors.
Introduction to semiconductor material properties; semiconductor diodes; structure and operation; diode circuit applications; bipolar transistor; structure and operation; junction field effect transistors JFETs ; metal oxide field effect transistors MOSFETs fabrication technology and construction of semiconductor devices; biasing and stability of amplifiers. This course is dually listed with an equivalent graduate-level course EE and requires a minimum GPA of 2.
Transducers; measurement techniques; measurement errors; digital signal processing; noise sources and reduction; introduction to LabVIEW software, data acquisition and processing using computer-controlled data acquisition hardware. Introduction to semiconductor devices; crystal growth and wafer preparation; chemical and physical vapor deposition; oxidation; diffusion; ion implantation; lithography; etching metallization, process integration of CMOS and bipolar technologies; diagnostic techniques and measurements; packaging; yield and reliability.
Introduction to the syntax and elements of the basic VHDL language such as entities and architectures; creating combinational, synchronous logic and state machines using both structural and behavioral VHDL; using hierarchy in large designs; synthesizing and implementing designs.
Credit for both EE and EE not allowed toward a degree. Introduction to design and analysis of computer networks. Polling networks and ring networks. Introduction to the syntax and elements of the basic Verilog language such as modules and ports; hierarchical modeling; gate-level modeling; dataflow modeling; switch-level modeling; tasks and functions; timing and delays; user-defined primitives; synthesizing and implementing designs.
Emphasis is on the simulation and test-bench aspects. Design projects utilizing bit and bit microprocessor hardware and software; interfaces to memory and peripheral devices. Prior credit for or concurrent registration in EE Digital design projects utilizing simulation and synthesis CAD tools and targeting programmable logic devices. Computer-aided modeling, design and performance analysis in time and frequency domain of analog and digital communication end-to-end systems, and automatic control systems.
Two-dimensional Fourier analysis; linear systems; sampling theory; scalar diffraction theory. Fourier transform imaging properties of lenses; frequency analyses of diffraction-limited coherent and incoherent imaging systems; aberrations and resolution analysis; Vander Lugt filters and frequency domain analysis and synthesis; SAR and pattern recognition applications.
Generation and transmission of high frequency electromagnetic energy; magnetrons, klystrons, masers, parametric amplifiers, traveling wave tubes and solid-state devices; waveguides and resonators.
Radiation fundamentals; linear antennas; loop antennas; aperture antennas; reflector antennas; antenna impedance and measurements; computer-aided design of antenna systems.
This course is dually listed with an equivalent graduate-level course EE Wave propagation in free-space and in wave guides; optical resonators; interaction of radiation and atomic systems; laser oscillation; solid-state lasers. He-Ne and Argon lasers, integrated optics including integration of emitters and detectors; optical interconnects; spatial light modulators; optoelectronic materials and devices; and applications of optoelectronics.
Review of optical principles, dielectric waveguides, signal propagation, degradations and attenuation of fibers. Fiber interconnection devices, active and passive components, optical transmitters and receivers, power budget, fiber optic communication systems.
Architecture and software of bit and bit microprocessor hardware and software; interface design to memory and peripheral devices; multiprocessing. Introduction to radar signal processing. Continuous wave and pulsed radars. Clutter and radio wave propagation. Moving target indicator, target surveillance and tracking radar systems. Side-looking, synthetic aperture, interferometric and other airborne radars.
Advanced digital filter structures and design. DSP algorithm design and implementation. Analysis of finite word length effects of DSP applications.
Extensive use of MatLab for analysis and design. Hardware and software principles of PLC devices, ladder logic, hardware components of PLC systems and controller configuration, basic PLC operation, program construction and manipulation, advanced operation and networking. Design techniques for high-speed digital interfaces and circuit boards; signal integrity including crosstalk and ground bounce; electromagnetic aspects of high-speed digital design; frequency-domain analysis of power-system integrity; state-of-the-art buses and standards.
Reliability of network functions high-pass, band-pass, low-pass, band reject and equalizing filters ; approximation techniques; sensitivity analysis; passive and active synthesis; positive and negative feedback and biquads. Computer techniques for the realization of standard filter forms Butterworth, Chebyshev, Bessel, Sallen and Key, and other forms. Introduction to wireless communications propagation in mobile radio channels, large, small scale fading and multipath; diversity and diversity combining techniques and modulation techniques.
Digital line coding; pulse shaping; partial response signaling; scrambling; M-ary communication; digital carrier systems and digital multiplexing. Probability; random variables; quantization error in PCM; random processes; white noise and the behavior of analog systems in the presence of noise.
Information theory; compact codes and error correcting codes. DC machines-motors and generators. Single-phase motors; unbalanced two-phase motors; servo-motors; commutator motors; stepper motors; synchros; shaded pole motors; reluctance and hysteresis motors and brushless DC motors. Dynamic circuit analysis of rotating machines. Design and analysis of switch mode power converters; design of magnetic components; stability considerations; input filter interactions; performance measurements and evaluations.
Principles of power system analysis. Synchronous machines, transformers and loads; transmission line parameters and analysis. Symmetrical fault studies and protective devices. Symmetrical components and sequence networks; computer studies of transmission lines; fault studies using a computer; state estimation of power system and power system stability, Economic analysis. Principles and characteristics of generating stations; transformers; conversion equipment; primary and secondary distribution systems; short-circuit calculations; selection of protective devices; system grounding and over current protection; voltage control; power factor control and correction; load and cost estimating.
Power semiconductor diodes and thyristors; commutation techniques; rectification circuits - uncontrolled and controlled; AC voltage controllers; DC chopper; pulse-width modulated inverters and resonant pulse inverters. Design and analysis of switch mode power converters; design of magnetic components; stability considerations; input filter interactions; performance measurements and evaluation.
This course is dually listed with an equivalent graduate level course and requires a minimum GPA of 2. Photometric units and definitions; light sources and luminaires; interior lighting and artificial illumination design techniques; daylight lighting design; exterior lighting design and the theory of color.
Optics and control of lighting. Introduction to renewable energy sources. Energy from water sources: This course is dually listed with an equivalent graduate course and requires a minimum GPA 2. These variables are held in shared memory in the Power PMAC, providing access from both tasks running under the real-time kernel and the general-purpose operating system, and both Power PMAC script programs and compiled C programs.
In normal use, it is not necessary for the user to know which variable the name has been assigned to. Power PMAC provides no range-checking functionality. Caution With a declared array name, the name can be used in vector or matrix function calls that require the starting variable number as an argument. This is most commonly used when converting projects from Turbo PMAC environment, which did not have the capability for automatically assigned declared variable names, but which did permit these manually assigned names.
Power PMAC has a large set of coordinate-system-specific global variables. These variables can be shared between multiple tasks working in the same coordinate system on the Power PMAC, but they are unique to each coordinate system. Since a motion program can be executed by multiple coordinate systems, these variables permit independent operation of the program in each coordinate system. Qi in Coordinate System x.
I-variables assigned to them. Each top-level program and each communications thread has its own independent set of these variables. StackOffset is declared for the program in the open command that precedes the downloading of program text. If the program is downloaded through the IDE project manager, the IDE automatically calculates and declares the smallest value of StackOffset needed to support the number of local variables used in that program.
For example, the declaration: The standard algebraic precedence rules are used: Use of parentheses can override these default precedence levels. These make sophisticated mathematical operations simple, compact, and efficient.
Each function is documented in detail in the Software Reference Manual. Expressions A Power PMAC script-language expression is a mathematical construct consisting of constants, variables, and functions, connected by operators.
Expressions can be used to assign a value to a variable, to determine a motion-program parameter, or as part of a condition. Since a constant alone is a valid expression, it is legal to put a constant in parentheses in these cases, but this takes more calculation time and storage.
This type of statement can only be used in a motion or PLC program; Why Needed in Motion Programs In a motion program, when Power PMAC is blending or splining moves together, it must be calculating in the program ahead of the actual point of movement. This is necessary in order to be able to blend moves together at all, and also to be able to do reasonable velocity and acceleration limiting. Next, the move command X Q1 is evaluated, and the resulting equations of commanded motion are placed in the motion queue.
It logically negates the explicit comparison or mathematical value inside the parentheses immediately following. If the comparison yields a true condition, the negation results in a false condition; if the comparison yields a false condition, the negation results in a true condition.
The E14 — E17 jumpers must be in their default settings in this case. Other ports can be used as well with custom cabling. For this setting, GateIo[i]. The starting bit of this byte on the bit data bus is specified by MuxIo.
Enable elements for the ports are not automatically cleared after communications with that port. UpdatePeriod is set to a value too small to be possible given the specified MuxIo. UpdatePeriod to a possible value. There are two advantages to using the user-defined pointer variables.
It supports 32 separate processes, permitting the user application to transfer control of each process robustly between tasks at different priority levels. An M-variable can be assigned to an individual bit of an element, or to a consecutive set of bits.
When the assignment is made through the IDE, an application-specific name can be given to the variable. The values in the image words for output ports are automatically copied to the actual outputs on the ACC boards, and the values in the image words for input ports are automatically copied from the actual inputs on the ACC boards.
This is both more robust and faster to execute. This provides an approach that is similar to that used in Script programs. The register pointer variables can be computed with program statements like the following. For local variables, these must be executed each time the routine is entered. So pointers to the 6 data registers of a single UMAC card could be defined as follows: This does not affect the reported value of inputs in the hardware register.
The Script environment does this automatically; it can be done through explicit program statements in C. To isolate the value of the bit corresponding to signal GPIN28 bit 11 in the second IC into a software variable, the following code could be used: The byte offset of this register is 0x No two boards in this class can have the same setting, or there will be an addressing conflict.
Use for that purpose is covered in the motor setup chapters. At a 15 kHz PWM frequency, this is log 10, , about The analog filtering has a cutoff -3dB frequency of 4. This frequency is not independent of the frequency used for the A, B, and C phases of the same channel.
It is also possible to assign an M-variable to the high 16 bits of the bit element using the address of the register rather than the element name.
To do this for the above example, the assignment would be: To do this for the above examples, the assignment would be: One can manipulate registers with program statements like the following e. Using the data structures as shown above, once the structure variable has been initialized with the GetGate3MemPtr i API function, individual elements of the structure can be directly accessed.
So a data structure to the ACCE3 card can be defined as shown above: DAC are shown in the following table: To write a value into the high 16 bits of the bit hardware element for DAC8 from a software variable with 16 bits, the following code could be used: So a data structure to the second Power Brick IC can be defined as shown above: So a data structure to the first Power Brick IC can be defined as shown above: Data Structure Method Using the data structures as shown above, once the structure variable has been initialized with the GetGate3MemPtr i API function, individual elements of the structure can be directly accessed.
The actual data is in the high 16 bits of the bit element. The status element for each input can be accessed as Clipper[i]. To write a value into the high 16 bits of this bit hardware register from a software variable MyDac1BValue with 16 bits, the following code could be used: If a program line begins with cexecn, the rest of the program line is only executed if bit n of bit element Coord[x]. Cflags is set to 1. Looping Structures Script programs in Power PMAC are capable of conditional looping structures, with the condition evaluated either at the beginning or end of the loop.
In a rotary motion program, only single-line loops can be used. Status for a top-level PLC program will contain a value of 5 to indicate this error. To facilitate this implementation, Power PMAC treats several of the letter codes as specialized subprogram call commands. The G, M, T, and D-codes provide a subprogram call as shown in the following table. When a move command is encountered during the execution of the Script program, Power PMAC generates the equations of commanded motion that are necessary to implement the move according the specified rules.
The program nofrax command makes all of the axes non-feedrate axes. PLC program to start a move simultaneously according to the modal move rules in place at the time the program line is encountered.
If the open prog n command is immediately followed by a close command, with no intervening buffered program commands, the program ceases to exist; it does not count against the limit for the number of motion programs that can be stored in the Power PMAC at one time.
Rotary Motion Programs The rules governing rotary motion program buffers are substantially different from those for the other types of Script program buffers. If the open plc n command is immediately followed by a close command, with no intervening buffered program commands, the program ceases to exist; it does not count against the limit for the number of PLC programs that can be stored in the Power PMAC at one time.
Subprograms A new subprogram can be downloaded to the Power PMAC at any time, even while other programs are executing. If the open subprog n command is immediately followed by a close command, with no intervening buffered program commands, the program ceases to exist; it does not count against the limit for the number of subprograms that can be stored in the Power PMAC at one time.
User Variable Names The IDE permits the use of meaningful variable names by the user, making the programs much more understandable. If you want to use a single variable for both purposes, you must declare it in both forms. Note that local stack variable Ri of the calling program is the same as Li of the called subprogram. Execution Rules for Script Programs While the Power PMAC script language syntax is the same for all types of programs, the rules for execution differ based on the type of program.
This section explains the execution rules for each type of program. However, it can be important to know how this sequencing works, particularly when trying to synchronize motion with other Note aspects of the machine control. AbortTs saved setup element values. In addition, some care may need to be taken with the setting of saved setup element Sys.
PreCalc servo cycles ahead of the presently executing point. Kinematic subroutines are called implicitly from programs as needed. They should not contain any motion commands themselves. Their primary purpose is to convert between axis and motor positions, but can contain other calculations as well e. These commands are explained in this section. If there is a forward-kinematic subroutine present for the coordinate system, Power PMAC assumes that it will calculate the starting axis positions correctly.
No motion program calculations are performed during this reverse execution of buffered moves. This variety permits the user to select whether the halting action begins immediately or not, whether motion stops at the end of a programmed move or not, whether motion can be resumed or not, and what state the motors are left in. If the program is presently executing moves from the dynamic lookahead buffer, the motors are decelerated to zero velocity, starting immediately, using motion Writing and Executing Script Programs in the Power PMAC Technically in this mode, the program and moves are still executing Coord[x].
Note that this includes motors in the coordinate system but not assigned to an axis — null definitions and spindle definitions. In general, the motors will not stop at a programmed point, and in a multi-axis application, the uncontrolled deceleration will not be along the programmed path. In general, the motors will not stop at a programmed point, and in a multi-axis application, the deceleration will not be along the programmed path.
This command sets status bits Plc[i]. Running to 1 for the affected PLC program s. These commands provide for different methods of stopping and subsequent re-starting. On-Line disable plc Command, Program disable plc Command The on-line or program disable plc command e.
This command leaves status bits Plc[i]. Active at 1 and sets Plc[i]. Running to 0 for the affected PLC program s. The subroutine can be as simple as: Under the RS standard, the parameters for G00 moves are not set in the program, but rather by system constants. JogSpeed, depending on the setting of Motor[x]. G01, G02, or G03 mode. For example, to use the letter P with a number specifying the time in seconds, the subroutine could be: In Power PMAC, this plane specification is performed using the normal command, which specifies the vector normal to the desired plane.
The standard implementation of these codes would be: G64 specifies continuous cutting mode, in which the moves are blended together without stopping. NoBlend, so the standard implementation of these codes would be: InvTimeMode of 2 or 3 compute the time for circle-mode moves differently from the setting of 1 used above.
Note that if any given axis specifier is found for a second time in one program line, Power PMAC interprets this point as the beginning of a new command line. This permits multiple moves to be condensed onto a single command line e. Successive rapid-mode moves are not blended together on the fly, as in other move modes, but it is possible to break into a rapid-mode move at the presently executing point and alter the move.
JogTa is less than Motor[x]. The profiles for both cases are shown in the figure below. Specification of acceleration parameters by rate is better for creating minimum-time moves for short distances. It is also better if you wish to issue new rapid move commands while the moves from previous commands are still executing, as the transition is seamless, even during accelerations. This value is always expressed as a relative distance, regardless of whether the axis is in absolute or incremental mode.
Both values are expressed in the axis user units. Note that the rate of acceleration is the same in each of the three acceleration sections, even though the changes in speed are different.
Triggered Rapid-Move Profile Breaking into a Rapid-Mode Move Uniquely among the Power PMAC programmed move modes, it is possible to break into an executing rapid-mode move at any time and command a new rapid-mode move, with all, some, or none of the move parameters changing. The move-until-trigger function is just one example of this capability. Fundamentally, since rapid-mode moves are executed like jog moves, they share If more than one move is specified in succession with no pause in between, the first move can blend into the second with the same type of controlled acceleration as is done to and from a stop.
Power PMAC calculates the move time as the vector distance of the feedrate axes divided by the programmed feedrate. InvTimeMode to a value greater than 0. Note that these elements are in units of inverse acceleration msec per motor unit , which yields quicker calculations by the Power PMAC. If the request for any motor exceeds the limit, the acceleration-section or segment time is extended so that motor will not exceed its limit; Each linear move that Power PMAC calculates is considered to be potentially the last move in a sequence, so Power PMAC checks the required rate to decelerate to a stop at the end of the move against the acceleration and jerk limits, extending this deceleration time as necessary to see that the limits are not violated.
Ta time of msec, a Td time of msec, and a Ts time of 0. Three separate sections are created from a single move command: S-curve time and deceleration time equal to acceleration time for various cases. SegMoveTime must be set greater than zero to enable segmentation in order for this conversion to occur. When returning to linear or circle mode, the axes should be restored as vector feedrate axes, using a command such as frax X,Y,Z.
Circular or similar paths can be executed on any plane in either of these 3D spaces. The first and most commonly used method is to specify a vector from the move start point to the center. The second method is to specify the magnitude of the radius and let Power If this is not the case, Power PMAC will execute a spiral path from the start point to the end point, continuously changing the radius of curvature along the path.
Following an industry convention, Power PMAC takes the short route if the R value is positive, and the long route if the R value is negative. R values are not modal — a value must be specified on each move command line. FeedTime is set to 60,, the F units are length units per minute. More details on this specification are given in the section on linear-mode moves, above.
F-code in the program. This is in part a protection against move times so short that Power PMAC could not calculate them in real time. If you are working with very short move segments particularly programmed by feedrate and your move sequence is going more slowly than you want, this acceleration-time limit may be the cause.
PVT-mode move section, below. These allow the user to optimize the application in any of several preferred methods. Note that these methods operate at the programmed move calculation time. Note how the blending time is constant over speed and corner angle. It illustrates how the blends vary with speed and angle. Note that the blended paths are identical at different speeds.
If buffered lookahead is used to execute the resulting path, the acceleration- limiting function of the lookahead can be used to further limit motor accelerations by automatically limiting speed along this path. The buffered lookahead does not change the path computed here. The following plot shows how the corners are executed in this mode. Actual Stop If saved setup element Coord[x]. This permits the user to program the path along the edge of the tool, letting Power PMAC calculate the tool-center path, based on a radius magnitude that can be specified independently of the program.
For this reason, Coord[x]. Zero-Distance Move Buffering Some applications will require additional pre-computation and buffering. I-1, which specifies the YZ-plane. N normal K-1 return; If you are implementing G-code subroutines in Power PMAC subprogram , you could simply incorporate into subprog Treatment of Compensated Outside Corners, below.
If the angle is sharper than this threshold, Power PMAC will execute an arc move, with radius of the cutter radius, about the uncompensated intersection point to a point perpendicular to the starting direction of the fully compensated move. If the moves are to be blended, the compensated path will be blended according to the acceleration times in force Coord[x]. The process is exactly the reverse of the process that introduces compensation.
Note that the length of the programmed lead-out move must be greater than the cutter-compensation radius; Treatment of Compensated Outside Corners, above. If the angle is sharper than this threshold, Power PMAC will execute an arc move, with radius of the cutter radius, about the uncompensated intersection point to a point tangent to a straight-line move to the programmed point of the lead-out move.
Power PMAC permits two different actions when interference in the compensated path is detected. If bit 1 value 2 of Coord[x]. Provided that the program has been told to pre-compute enough moves, motion will be stopped before the resulting overcut would occur.
For debugging purposes, bit 2 value 4 of Coord[x]. CCCtrl can be set to 1. This setting is suggested mainly for dry-run modes, to be able to detect more clearly what the source of the problem is. Shallow Pocket, Interference Check Disabled The following XY path plot shows the same uncompensated and compensated paths, but this time with interference checking enabled for the compensated moves. When given a single-step command with 2D compensation active — an on-line s command or a buffered program step command — Power PMAC computes enough moves ahead so that it can execute one move, taking that move out of the compensated move buffer.
At the beginning of a compensated move sequence, it must compute enough moves to get Coord[x]. The 3D compensation algorithm automatically uses this data to offset the described path of motion, compensating for the size and shape of the tool.
This permits the user to program the path along the surface of the part, letting Power PMAC calculate the path of the center of the end of the tool. Sample Tool-Tip Geometry User sets: Note that the user should not enter values for these elements using the Script language, and should not enter the arc-piece section data using C-language commands.
Compensation will be removed over the next linear mode or circle not recommended mode move after compensation has been turned off. Then several offsets are applied to the X, Y, and Z-axis positions.
The first offset is taken along the surface-normal vector, of a magnitude equal to the defined CutRadius for the arc-piece section of the tool-tip that is in contact with the part given the surface-normal and tool-orientation vectors in force.
It will set Coord[x]. If the command backup Coord[x]. Status is used, the text name of the error will be reported for ErrorStatus. In these moves, the user specifies the axis states directly at the transitions between moves unlike in linear or circle-mode moves. This requires more calculation by the host, but allows tighter control of the profile shape. The following diagram gives an example of such an arbitrary PVT-mode sequence.
The following drawing shows one technique for computing the the axis velocities at each programmed point of a contour. This was not possible in earlier PMAC generations. Unlike blending between linear and circle mode moves themselves, this does not include a separate blend section governed by acceleration- time parameters.
Note that if the PVT-mode move is executed in single-step mode with segmentation and the special lookahead buffer active, the lookahead acceleration control will keep the profile within the acceleration limits, but the profile will look nothing like that for continuous execution.
It generates profiles and paths known as non-rational cubic B-splines. The time profiles are guaranteed to be continuous in position, velocity, and acceleration, even at move boundaries. Power PMAC stores the times for the three sections of a programmed spline move in the data structure elements Coord[x].
T0Spline for the incoming section , Coord[x]. T1Spline for the center section , and Coord[x]. T2Spline for the outgoing section. T2Spline used for the matching section of the previous move. Because the profiles for each axis are guaranteed to be continuous in both velocity and acceleration, the resulting commanded path is guaranteed to be continuous in both direction and curvature.
Power PMAC stores data on these segments in a specially defined lookahead buffer for the coordinate system. Each segment takes Coord[x]. SegMoveTime milliseconds when it is put into the buffer, but this time can be extended if it or some other segment in the buffer violates a velocity or acceleration limit.
This permits the user to command high speeds, and to have Power PMAC slow down the path only where needed. Note that the post-lookahead profile in this diagram is not time-extended as it would really be; The following list quickly explains the steps required for setting up and using the lookahead function on the Power PMAC. Greater detail and context are given in the subsequent section.
Assign all desired motors to the coordinate system with axis definition statements. LHDistance plus any segments for which backup capability is desired. Nothing special needs to be done to the motion program. The motion program defines the path to be followed; the lookahead algorithm may reduce the speed along the path, but it will not change the path. Power PMAC checks the actual position for each motor as the trajectory is being executed against these limits; An intermediate point for each motor is computed once per segment from the programmed path, and then a fine interpolation using a cubic spline to join these segments is executed at the servo update rate.
Ta time is typically set equal to the minimum desired block time, and the Ts time is typically set to 0 because it squares up corners. Interpolation errors The cubic-spline interpolation technique that Power PMAC uses to connect the intermediate segment points is very accurate, but it does create small errors.
These errors can be calculated as: Defining the lookahead buffer In order to use the lookahead function in a Power PMAC coordinate system, a lookahead buffer must be defined for that coordinate system, reserving memory for the buffer.
This is done with This is sufficient memory for virtually all applications. If Power PMAC initially computes a smaller move time, typically as vector-distance divided by vector-feedrate , it will increase the time to be equal to the acceleration time, slowing the move. Acceleration limits are not necessarily observed during the ramp up from a stop here. M-variable assignments starting again. This is a new feature in V1.
This delay is necessary to ensure that acceleration limits are always observed. In Power PMAC, this is achieved by means of assigning the relevant motors to axes in the same coordinate system, and commanding the axes together in a motion program.
It is recommended that the value be entered as an expression so Power PMAC can compute the result precisely. The default value of pMasterEnc for all motors is EncTable. However, if the encoder Changing Following Mode The following mode is used in determining how the calculations relating programmed axis position to underlying motor position are performed, so changing the mode changes how these Synchronizing Power PMAC to External Events If this element is set to its default value of 0.
ActiveMasterPos the limited position. Position lock is re-established when these two elements have the same value. Note that acceleration limiting can only be enabled if velocity limiting is also enabled Motor[x].
Note that the initial slave-motor acceleration is kept well below the specified limit at which the final slave-motor deceleration occurs. This is due to the fact the Power PMAC is limiting the speed so that a deceleration to zero velocity could occur within the specified acceleration limit, even if there were no further change in master position. This is shown in the following plot: This is fine for a great number of applications. In these applications, we really want to specify the trajectories as functions of master position, not of time.
The key advantage of the cam table approach is that the master can be fully bi-directional, whereas the time-base master must be fundamentally uni-directional. Sometimes, the user desires that the actual motion of the commanded trajectory be directly proportional to the master signal frequency, without any lag much like in electronic gearing. There is a quadrature encoder on the web that provides 40 lines per mm. When the web is moving at nominal speed, the crosscut move should take 0.
You want to repeat the crosscut every mm of the web material. That is, the output value at EncTable[n]. DeltaPos will be exactly 0. ACCE2A board at the default address. The spindle has a nominal speed of rpm 20 revolutions per second , which we will use as the real-time speed. The resulting real-time input frequency is Electronic cam tables are a commonly used method of synchronizing motion to an external position. Note that for position data to have this hardware-capture capability, it must be processed through the encoder counter of an IC servo channel.
CaptFlagSel specifies which flag in the set is used. Homing-search moves on-line or in a motion program 2. Position-Capture Monitoring Function Power PMAC can monitor a motor for a position-capture event, automatically processing the captured sensor position into a motor position and storing that position for the user.
This functionality is new in V1. While this monitoring function Use of other units for either will require rescaling. Motor Offset and Scaling When the motor is homed, Power PMAC stores the value of the encoder position in motor units at the motor zero position whether this is the same as the trigger position, or different as specified by a non-zero value in saved setup element Motor[x].
HomeOffset is stored in status