Towmotor Corporation

Caterpillar Industrial Inc.

Caterpillar Tractor Co.

Grant C Melocik

William Pickering

John E Wible

Wayne T Wiblin

Joseph J Harding

David Gurwicz

Edward V Leskovec

Kenneth A Baumgartner

James G Blaha

Frank S Buchwald

Edmund Gregg

Juurong Hsieh

Keith A Stoller

Steven E Blight

Ronald D Surma

A sensing apparatus capable of delivering a control signal in response to contact between an element of the apparatus and an external object should respond readily to a predetermined level of contact, and should be sensitive along all portions of the contact sensing surface. The instant invention provides a contact sensing apparatus including a conduit having a generally hollow tubular construction and being formed a resilient deformable material. A sonic generator is connected to one end of the conduit and a sonic detector is connected to the other end of the conduit. An electrical circuit is connected to the sonic generator and sonic detector, and is adapted to controllably produce a control signal in response to contact between the conduit and an external object. The instant invention is advantageously free from electro-mechanical switches and optical devices likely to be contaminated when used in an industrial environment, and requires no seals or other precautions necessary to contain pressure or fluid within the conduit.

Contact sensing apparatus and method

An apparatus for detecting obstacles in the path of a work vehicle, in which a transducer produces radiant energy, receives radiant energy reflected from an obstacle and produces an obstacle detected signal in response to receiving the reflected radiant energy. A rotatable reflector projects the radiant energy produced by the transducer radially outwardly from the work vehicle and directs the reflected radiant energy back to the transducer. An encoder produces an enable signal in response to predetermined positions of the rotatable reflector and is located along the same axis of rotation as the optical reflector. Zone control logic receives the obstacle detected signal and the enable signal and produces a vehicle control signal if both signals are present.

Scanning obstacle detection apparatus

An apparatus for an electric drive vehicle which provides linear deceleration via electrical braking. The apparatus monitors vehicle speed and adjusts the duty cycle of a chopper circuit according to look-up tables. These table correlate vehicle speed and desired deceleration rate to braking torque, thereby enabling the apparatus to maintain a preselected deceleration through the entire stopping distance and to precisely position the vehicle.

Electric braking control

Collision detection systems are commonly provided on automatic guided industrial vehicles. Such systems should be as reliable as possible and can advantageously utilize a fault detection apparatus. The subject apparatus provides a plurality of radiant energy emitting devices and receiving devices positioned along a vehicle at locations sufficient that an obstacle in a respective path of the vehicle interrupts the reception of radiant energy by respective ones of the receiving devices. Interruptable devices controllably connect a power supply to a brake control circuit in response to continuous reception of radiant energy by the respective receiving devices, and disconnect the power supply from the brake control circuit in response to any of the receiving devices failing to continue to receive radiant energy from the respective emitting device. A vehicle control circuit controllably produces first and second energization signals in response to a predetermined condition of the vehicle, and first and second switches receive respective ones of the first and second energization signals and responsively controllably supply electrical power from the power supply to predetermined ones of the emitting devices and the receiving devices.

Obstacle detection apparatus

Motor control circuits having fault protection devices are in commercial use today. Such devices typically include logic elements requiring a conditioned power supply, and are incapable of operation directly from the main motor power supply. The subject apparatus includes a timing circuit for monitoring the electrical conduction of a power switching element associated with an electrical motor. The apparatus produces a fault signal in response to the power switching element continuing to conduct for longer than a predetermined continuous period of time. A latch receives the fault signal and responsively produces a blocking signal. An interrupt circuit receives the blocking signal and responsively controllably blocks power from the motor power supply to the electrical motor. Each of the timing, latch, and interrupt circuits is adapted to operate directly from the motor power supply and independent of any intermediate logic power supplies or associated logic devices.

Fault protection apparatus for traction motor circuit

Automatic guided vehicles are commonly used in industrial material handling operations. Such vehicles must be accurately docked at predetermined stop locations without the guidance or assistance of human operators. The subject apparatus is used in conjunction with a vehicle having a vehicle drive circuit for controllably propelling the vehicle at a velocity responsive to a velocity command signal. At least one ground engaging wheel is equipped with a vehicle brake for controllably stopping the vehicle in response to a brake actuation signal. A position determining element produces a controlled stop signal in response to the vehicle being positioned a predetermined distance from the desired stop location, and an absolute stop signal in response to the vehicle being positioned at the desired stop location. A logic control circuit receives the stop signals and produces a brake actuation signal having a value sufficient to partially engage the vehicle brake and a velocity command signal having a value sufficient to continue to propel the vehicle at a predetermined low velocity in response to receiving the controlled stop signal. The logic control circuit produces a velocity command signal having a minimum value in response to receiving the absolute stop signal.

Vehicle docking apparatus and method

Information related to the position of a control member of a vehicle is required for control of power delivered to the vehicle motors. Available linear position encoders are expensive and prone to damage in an industrial environment. The instant apparatus provides a simple and durable linear position encoder having a piston adapted to move within a housing. A plurality of sensors are each positioned along a different housing pathway and a plurality of sensible members are each positioned along a different piston pathway. In response to movement of the piston within the housing the sensors deliver respective position signals to an electric circuit means, which, in turn, delivers respective coded digital signals to a vehicle controller. The apparatus is digital in design and is of simple, rugged, and inexpensive construction.

Linear position encoder

The subject brake test apparatus operates in conjunction with a vehicle having a source of power, a traction motor controllably connected to the power source and to at least one vehicle wheel, and a vehicle brake associated with at least one vehicle wheel. An actuator controllably engages and disengages the vehicle brake in response to receiving respective brake control signals, and a transducer produces wheel rotation signals in response to rotation of at least one of the vehicle wheels. A processor controllably delivers a brake engaging signal to the actuator and engages the vehicle brake. A predetermined amount of power from the power source is delivered to the traction motor for a predetermined period of time. In response to receiving wheel rotation signals from the transducer, the processor determines the degree of rotation of the vehicle wheels during at least a predetermined portion of the period of time that the traction motor is energized, and produces a brake status signal in response to amount of rotation of the vehicle wheels. The brake test apparatus advantageously produces an objective result, and is fully automatic in operation. Therefore, it is particularyl well suited to use on unmanned vehicles.

Apparatus and method for testing vehicle brakes

Information related to the rotary angular position of a steerable wheel portion of an electric vehicle is required for proper control of the vehicle and especially for differential control of the driven wheels of the vehicle. Available rotary position encoders are expensive, prone to damage in an industrial environment, and sensitive to misalignment between the encoder components. The instant apparatus provides a simple and durable rotary position encoder having a plurality of sensors positioned on a first mounting member and a plurality of sensible members positioned on a second mounting member. The apparatus is digital in design and the particular location and arrangement of the sensors and sensible members advantageously compensates for overtravel and misalignment of the encoder components.

Angular rotary position encoder

Controlling arrangements of the type used for aligning a load engaging assembly with a load to be lifted tend to be bulky, costly, unable to accurately position the load engaging assembly with the load to be lifted, and unable to accommodate different types of load supporting structures. A controlling arrangement having a signal assembly having first and second spaced apart portions is provided. The first portion is adapted to deliver a first signal and receive a reflection of the first signal and the second portion is adapted to deliver a second signal and to receive a reflection of the first signal. A single sensing device is adapted to receive the reflected signals and a selecting device controls the operation of the first and second signal assembly portions. Therefore, the problems of bulk, cost, inaccuracy and flexibility are eliminated. The controlling arrangement is particularly suited for use on a material handling vehicle.

Controlling arrangement

Apparatus is provided for controlling increases in the speed of a motor, including a transducer coupled to an accelerator pedal, that generates digital numbers representing motor speed commands, a data processor for receiving the speed commands, generating motor speed limit signals in response to the digital numbers and delivering the limit signals to a controllable circuit for supplying power to the motor. The limit signals are delivered in response to time and the magnitude of the speed commands.

Motor speed control apparatus

A control system (28) is provided for controlling the supply of power to a motor (12) having an armature (34) and a plugging diode (38) connected across the armature (34), including a circuit (14) for producing direction command signals, a circuit (98) for generating digital motor power command signals, a circuit (16) for sensing a plugging condition and generating a plug signal, a microprocessor (46) for generating one of a plurality of pulse trains during typical plugging conditions and for automatically overriding the generation of the one pulse train and generating other of the plurality of pulse trains during special plugging conditions. By automatically providing the override feature during the special plugging conditions, the disadvantage of manual override in prior control systems is obviated.

Plugging and plugging override control apparatus

The invention pertains to an apparatus (10) for diagnosing and displaying the condition of various components in an electro-mechanical vehicle or other system. The apparatus (10) includes command signal producing devices (12), control signal receiving devices (14), and means (16) for delivering control signals to the receiving devices (14) in response to receiving the produced command signals. The means (16) includes means (128) for receiving diagnostic command signals and displaying a predetermined diagnostic code in response to receiving a predetermined command signal. Both in-service and out-of-service diagnostics are provided for and a minimum of equipment external to the apparatus (10) is required, thus making the system both efficient and low in cost.

Diagnostic display apparatus

The invention pertains to a control system (46) for controlling the supply of power to a motor (12) to produce plugging electrical braking and current limit control, including a circuit (60) for controlling the direction of energization of the motor (12), a circuit (88) for generating digital numbers representing command motor speeds, a circuit (14) for generating a data signal representing a plugging condition, a programmable data processor (18) for generating pulse trains in dependence on the plugging condition, and a power transistor element (40) for coupling power to the motor (12) in response to the pulse trains. By using state-of-the-art digital, integrated circuit and software technology, prior, essentially linear or discrete component technology, which is relatively unreliable, expensive and slow, need not be used.

Plugging electrical braking control circuit

Apparatus (10) is provided for controlling current through a motor (12), including a circuit (14) for generating motor speed command data, a circuit (26) for generating a control signal in response to a maximum value of current through the motor (12), a programmable data processor (72) for generating pulse trains in response to the command data, and a controllable supplying circuit (18) for coupling and decoupling power to the motor (12) in response to the pulse trains and for decoupling power to the motor (12) in response to the control signal independent of the pulse trains. By decoupling power from the motor (12) independent of the control produced by the data processor (72), the current limit is achieved even if the data processor (72) malfunctions, contrary to prior apparatus.

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Chardon, OH, United States of America

Grant C Melocik