System for projecting vehicle speed and tire condition monitoring system using same

A system for monitoring tire conditions of a vehicle comprising:

• first detecting means for detecting an unsprung vibration frequency component acting on a front wheel to provide a signal indicative thereof;
• second detecting means for detecting an unsprung vibration frequency component acting on a rear wheel to provide a signal indicative thereof;
• phase difference determining means, responsive to the signals from said first and second detecting means, for determining a phase difference between the unsprung vibration frequency components acting on the front and rear wheels to provide a signal indicative thereof;
• vehicle speed projecting means, responsive to the signal from said phase difference determining means, for projecting an absolute speed of the vehicle based on the phase difference and the wheel base of the vehicle;
• wheel speed determining means for determining a wheel speed;
• and
• tire condition determining means for determining a change in tire radius during traveling based on the wheel speed determined by said wheel speed determining means and the absolute speed of the vehicle projected by said vehicle speed projecting means.

A system for monitoring tire conditions of a vehicle comprising:

• first detecting means for detecting an unsprung vibration frequency component acting on a front wheel to provide a signal indicative thereof;
• second detecting means for detecting an unsprung vibration frequency component acting on a rear wheel to provide a signal indicative thereof;
• phase difference determining means, responsive to the signals from said first and second detecting means, for determining a phase difference between the unsprung vibration frequency components acting on the front and rear wheels to provide a signal indicative thereof;
• vehicle speed projecting means, responsive to the signal from said phase difference determining means, for projecting an absolute speed of the vehicle based on the phase difference and the wheel base of the vehicle;
• wheel speed determining means for determining a wheel speed;
• unsprung resonance frequency determining means for determining an unsprung resonance frequency;
• and
• tire condition determining means for determining a dynamic loaded tire radius based on the wheel speed determined by said wheel speed determining means and the absolute speed of the vehicle projected by said vehicle speed projecting means,
• wherein said tire condition determining means includes tire type specifying means for specifying a type of tire used on the vehicle based on the dynamic loaded tire radius and the unsprung resonance frequency.

A system for monitoring tire conditions of a vehicle comprising:

• first detecting means for detecting an unsprung vibration frequency component acting on a front wheel to provide a signal indicative thereof;
• second detecting means for detecting an unsprung vibration frequency component acting on a rear wheel to provide a signal indicative thereof;
• phase difference determining means, responsive to the signals from said first and second detecting means, for determining a phase difference between the unsprung vibration frequency components acting on the front and rear wheels to provide a signal indicative thereof;
• vehicle speed projecting means, responsive to the signal from said phase difference determining means, for projecting an absolute speed of the vehicle based on the phase difference and the wheel base of the vehicle;
• wheel speed determining means for determining a wheel speed;
• unsprung resonance frequency determining means for determining an unsprung resonance frequency;
• and
• tire condition determining means for determining a first dynamic loaded tire radius of a tire showing a preselected amount of tire wear based on the unsprung resonance frequency and a second dynamic loaded tire radius based on the wheel speed determined by said wheel speed determining means and the absolute speed of the vehicle projected by said vehicle speed projecting means, said tire condition determining means finding a difference between the first and second dynamic loaded tire radii to determine an amount of tire wear.

A system for projecting the absolute speed of a vehicle comprising:

• first detecting means for detecting a wheel speed of a front wheel to provide a front wheel speed indicative signal including at least one of unsprung vertical and longitudinal resonance frequencies due to vibration inputs acting on the front wheel from a road surface;
• second detecting means for detecting a wheel speed of a rear wheel to provide a rear wheel speed indicative signal including at least one of unsprung vertical and longitudinal resonance frequencies due to vibration inputs acting on the rear wheel from the road surface;
• phase difference determining means, responsive to the signals from said first and second detecting means, for determining a phase difference in said at least one of unsprung vertical and longitudinal resonance frequencies between the front wheel speed indicative signal and the rear wheel speed indicative signal;
• and
• vehicle speed projecting means, responsive to the signal from said phase difference determining means, for projecting the absolute speed of the vehicle based on the phase difference and the wheel base of the vehicle.

A system for projecting the absolute speed of a vehicle comprising:

• first detecting means for detecting a wheel speed of a front wheel to provide a front wheel speed indicative signal including at least one of unsprung vertical and longitudinal vibration frequency components caused by vibration inputs acting on the front wheel from a road surface;
• second detecting means for detecting a wheel speed of a rear wheel to provide a rear wheel speed indicative signal including at least one of unsprung vertical and longitudinal vibration frequency components caused by vibration inputs acting on the rear wheel from the road surface;
• phase difference determining means, responsive to the signals from said first and second detecting means, for determining a phase difference in said at least one of unsprung vertical and longitudinal vibration frequency components between said first and second detecting means to provide a signal indicative thereof, said phase difference determining means determining a first time a maximum value of the unsprung vibration frequency components acting on the front wheel is generated and a second time a maximum value of the unsprung vibration frequency components acting on the rear wheel is generated, said phase difference determining means finding a difference between the first and second times to determine said phase difference;
• and
• vehicle speed projecting means, responsive to the signal from said phase difference determining means, for projecting the absolute speed of the vehicle based on the phase difference and the wheel base of the vehicle.

A system for projecting the absolute speed of a vehicle comprising:

• first detecting means for detecting a wheel speed of a front wheel to provide a front wheel speed indicative signal including unsprung vibration frequency components caused by vibration inputs acting on the front wheel from a road surface;
• second detecting means for detecting a wheel speed of a rear wheel to provide a rear wheel speed indicative signal including unsprung vibration frequency components caused by vibration inputs acting on the rear wheel from the road surface;
• phase difference determining means, responsive to the signals from said first and second detecting means, for determining a phase difference in said unsprung vibration frequency components between said first and second detecting means to provide a signal indicative thereof;
• and
• vehicle speed projecting means, responsive to the signal from said phase difference determining means, for projecting the absolute speed of the vehicle based on the phase difference and the wheel base of the vehicle.