Control and method for positioning a tool of a construction apparatus

A control system for establishing at least one of grade and elevation control for a tool on a construction apparatus, said control system for maintaining a vertical lateral position of the tool relative to a reference, the tool being movably mounted on a construction apparatus, and the construction apparatus including at least one positioning device that responds to signals from said control system to adjust the position of the tool, control system comprising:

• a first sensor configured to be carried by construction tool, said first sensor measuring distance to a reference and generating sensor signals, said sensor signals being a function of the distance to the reference;
• a sensor control coupled to said first sensor and adapted to define a target position, said sensor control comparing said sensor signals with said target position of the construction tool, said sensor control selectively producing a drive signal in response to the relationship of said sensor signals to said target position and transmitting the drive signal to the tool positioning device to maintain a desired position of said construction tool with respect to said reference;
• a reflector;
• and
• a second sensor coupled to said sensor control and spaced from said first sensor the distance, said reflector being spaced from said second sensor less than said distance whereby said reflector is at least in close proximity to said second sensor, said first sensor generating at least a first sensor signal, said second sensor detecting a first reflection of said first sensor signal from said reflector, and said sensor control determining the local speed of sound based on said first reflection.

A method of controlling the grade and elevation of a tool on a construction apparatus relative to a reference, the construction tool being movably mounted on a construction apparatus, and the construction apparatus including at least one positioning device for adjusting the position of the construction tool, the method comprising the steps of:

• providing a controller and first and second ultrasonic transducers on the construction apparatus in a spaced relationship having a distance therebetween;
• mounting a reflector at a distance to said second transducer that is less than the distance between the transducers to provide a close reflector;
• driving said first transducer to produce an acoustic wave;
• monitoring the time reflections of the acoustic wave are respectively received by said first and second transducers;
• determining the local speed of sound based on a first in time reflection received by the second ultrasonic transducer;
• determining the distance from the construction tool to a reference based on the local speed of sound and a second in time reflection received by said first and second ultrasonic transducers;
• and
• producing at least one electrical signal with said controller as a function of the distance.

A method for controlling a tool on a construction apparatus relative to a reference, the construction tool being movably mounted on a construction apparatus, the construction apparatus including at least one positioning device having a solenoid operated hydraulic valve for adjusting the position of the construction tool, the method comprising the steps of:

• providing at least one sensor on the construction apparatus;
• providing a sensor control;
• coupling said sensor control to the at least one sensor;
• communicating and driving said sensor with said sensor control;
• generating sensor signals as a function of the distance from the sensor to a reference with said sensor;
• determining the position of the construction tool relative to the reference based on the sensor signals;
• producing a drive signal in response to said sensor signals with said sensor control;
• transmitting said drive signal to the tool position device to maintain a desired position of the construction tool with respect to the reference;
• and
• detecting a particular configuration of the solenoid operated hydraulic valve and producing the drive signal based on the detected configuration of the at least one solenoid hydraulic valve.

A method of controlling the elevation of a tool of a construction apparatus and for maintaining the vertical position of the tool relative to a reference, the tool being carried by the construction apparatus, and the construction apparatus including at least one positioning device that responds to actuating signals to adjust the position of the tool, said method comprising:

• providing a transducer assembly comprising at least one ultrasonic transducer being configured to be carried by the construction apparatus, the transducer having an emitting surface and a screen;
• driving said transducer assembly to produce an acoustic wave;
• providing a reflector at the screen of the transducer;
• receiving at least one reference reflection of the acoustic wave from a reference and at least one reflector reflection is received from the reflector;
• monitoring the time the reflection of the acoustic wave are received by the transducer assembly;
• determining the local speed of sound based on a first in time reflector reflection is received by said transducer assembly from the reflector;
• and
• determining the distance from the construction tool to the reference based on the received at least one reference reflection and the local speed of sound.

A control system for establishing at least one of grade and elevation control of a tool of a construction apparatus and for maintaining at least a vertical position of the tool relative to a reference, the tool be carried by the construction apparatus, and the construction apparatus including at least one positioning device that responds to signals from said control system to adjust the position of the tool, said control system comprising:

• a first transducer configured to be carried by the construction apparatus, said first transducer transmitting and receiving energy waves;
• first and second reflectors, said first reflector comprising a close reflector and said second reflector comprising a remote reflector;
• a second transducer configured to be carried by the construction apparatus, said second transducer being spaced a distance from said firsts transducer and receiving energy waves, and said close reflector being spaced from said second transducer less than the distance between said transducers;
• a controller coupled to said first and second transducers, said controller driving said first transducer to produce an energy wave and monitoring a first in time reflection received by said second transducer from said close reflector;
• and
• said controller determining the local speed of sound based on the first in time reflection received by said second transducer and determining the distance from the construction tool to a reference based on local speed of sound and a second in time reflection from the reference received by both of said first and second transducers.