Encoder controlled stepper motor system

• US 6,646,403 B2
• Filed: 03/20/2002
• Issued: 11/11/2003
• Est. Priority Date: 03/20/2002
• Status: Active Grant

• Current Assignee: Stephen Nabarowsky
• Original Assignee: Stephen Nabarowsky
• Inventors: Nabarowsky, Stephen
• Primary Examiner(s): Masih, Karen
• Application Number:
  US10/101,663
• Publication Number:
  US 20030178963A1
• Time in Patent Office: 601 Days
• Field of Search: 318/567, 318/569, 318/34, 318/600
• US Class Current: 318/567
• CPC Class Codes: G05B 19/40 Open loop systems, e.g. using stepping motor
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/34391 Synchronize axis movement and tool action, delay action, simulation inertia
• CPC Class Codes: G05B 2219/37139 Sampling output of encoder at precisely defined intervals
• CPC Class Codes: G05B 2219/41326 Step motor
• CPC Class Codes: G05B 2219/43198 Coupling and step motor

Abstract

The present invention is a motor controller. An encoder manipulates the motor controller in a manner that is new and novel. The encoder tracks movement of a material along an assembly line and reports the results of the tracking through electronic signals. Those electronic signals are used to manipulate the motor controller to produce unique and responsive control signals to manipulate the motors, particularly during the acceleration and deceleration of the motors. Other motor control systems have used encoders as a part of a feedback loop, but none allow encoders to exert the level of control over the motors as accomplished in the present invention.

Claims

1. A motor controller for controlling motors along an assembly line, the motors including at least one movement motor and at least one manipulating motor, the at least one movement motor engaging a material in movement across the assembly line, the controller comprising:

a programmable circuit;

an encoder physically in contact with the material on the assembly line;

at least one responsive electronic signal transmitted by the encoder to the programmable circuit, wherein the electronic signal is indicative of the material moving a preprogrammed distance; and

at least one control signal transmitted from the programmable circuit and received by the movement motors relative to the electronic signals thereby causing the movement motors to maintain a present speed until the material moves the preprogrammed distance.

2. The motor controller of claim 1 wherein the electronic signals are step signals and each step signal corresponds to the material moving the preprogrammed distance along the assembly line.

3. The motor controller of claim 1 wherein the programmable circuit comprises:

a data memory, which stores a set of anticipated control data; and

a latch connected to the data memory and, indirectly, to the encoder, wherein the latch receives a modified electronic signal indirectly from the encoder and the set of anticipated control data from the data memory and generates control signal data whereby when the encoder tracks a speed of the material equal to the speed of the movement motors, the generated control signal data increases the speed of the movement motors to a next step as defined by the anticipated control data.

4. The motor controller of claim 1 wherein the programmable circuit comprises:

a ramp control counter connected to the encoder and receiving the responsive electronic signal, wherein the ramp control counter controls an acceleration and a deceleration of the at least one movement motor when the material is moving the preprogrammed distance; and

an operator counter connected to the encoder and the ramp control counter wherein the operator counter initiates the deceleration of the at least one movement motor.

5. A method of controlling motors along an assembly line, said method comprising the steps of:

initiating at least one movement motor at a present rate;

pulling a material along the assembly line using the movement motor;

identifying a distance traveled by the material over regular time intervals using an encoder;

determining when the material is traveling at a same rate as the movement motor using a programmable circuit; and

incrementally increasing the present rate of the movement motors when the material is traveling at the same rate as the movement motor.

6. The method of claim 5 wherein the encoder transmits step signals to the programmable circuit over the regular time intervals thereby providing the programmable circuit with the necessary information to determine when the material is moving at the same rate as the movement motor.

7. The method of claim 5 wherein the programmable circuit contains a data memory, which stores an acceleration curve and a deceleration curve, which are used to determine the incremental increases in the present rate of the motor.

8. The method of claim 7 wherein the programmable circuit further contains a latch, wherein the latch transmits a signal from the data memory to the movement motors to incrementally increase the present rate of the movement motor when the movement motor is operating at the same rate at which the material is traveling.

9. The method of claim 7 further comprising the step of programming an operator counter to initiate the deceleration curve when the material has traveled a predetermined distance.

10. The method of claim 5 wherein the steps are repeated a plurality of times until the material reaches a final rate of movement.

11. A system for controlling motors along an assembly line, which has a material on the assembly line, the system comprising:

a movement means for moving the material across the assembly line;

a manipulating means for manipulating at least a portion of the material on the assembly line;

a tracking means for directly tracking movement of the material across the assembly line; and

a control means for controlling the movement means and the manipulating means based at least partly on input from the tracking means.

12. The system of claim 11 further comprising a counting means for counting actions taken by the movement means and the manipulating means.