The present invention relates to electric power steering systems. Electric power steering (EPS) systems typically include an electric assist motor for providing power assist to a driver-operated steering mechanism. In an EPS system, the driver-operated steering mechanism is typically a steerable vehicle steering system (e.g., a vehicle steering column) having a steering input shaft (e.g., a steerable wheel shaft) rotatably coupled to an output shaft (e.g., an output shaft of the electric assist motor) via a torsion bar that is typically provided by a torsion bar assembly. The electric assist motor may be any of a variety of types, such as a DC motor, an AC motor, or an IPM (Induction Motor). These motors may further be brush or brushless types, and may include permanent magnet or variable reluctance types. For example, the IPM can include a squirrel cage induction motor, a reluctance motor, or other such alternating current (AC) motor. In one type of EPS system, a portion of the steering input shaft is rotatably coupled to an input yoke of the IPM (e.g., a coupling portion of the input yoke is directly or indirectly connected to the steering input shaft), while another portion of the input yoke is rotatably coupled to a motor output shaft of the electric assist motor. In some EPS systems, the input yoke is provided by a torsion bar assembly including an input yoke formed from an input portion and a torsion portion. The EPS system typically includes a motor controller configured to control operation of the electric assist motor. Typically, the motor controller includes at least one microprocessor that controls motor operation based on various input and output signals. In addition to motor operation control, the microprocessor also may control other EPS system functions, such as one or more valves that selectively control flow of hydraulic fluid, as well as the operation of a battery (e.g., battery charge control) and a steering controller (e.g., an EPS driver control). Various EPS systems have been developed to include a control unit (e.g., a vehicle control unit or vehicle ECU) operable to carry out various functions, such as motor position (e.g., current) feedback and motor rotation speed (e.g., rpm) feedback. For example, during the operation of a vehicle, some of the above-described functions may need to be adapted to the dynamics of the vehicle operation, in part to ensure correct IPM position control. As used herein, “dynamics” means various parameters such as system bandwidth, gain characteristics, and the like, that are typically associated with operating conditions of a vehicle or vehicle systems. Because of the dynamic nature of a vehicle, the control unit is typically configured with a set of predefined operating and calibration parameters. This set of predefined operating and calibration parameters has been found to be generally effective for the intended range of operating conditions, and/or vehicle models, of the EPS systems. However, in some cases, there is a desire to limit the set of predefined operating and calibration parameters in order to reduce the cost of the control unit. Some previous attempts to provide adaptive control have provided for a predefined, but adaptive control unit operating parameters. For example, in an EPS system that includes an electric assist motor connected to an input yoke of a torsion bar assembly via a steering input shaft, previous attempts to provide adaptive control have included an adaptive control algorithm that operates to modify the predefined operating parameters of the steering system (e.g., in the absence of a driver-controlled steering operation) and store these parameters in nonvolatile memory of the control unit. The adaptive algorithm typically includes a low pass filter configured to operate to detect wheel steering behavior from a “wheel position model” and a “torque model” based on multiple previous wheel position and torque values. The torque values are typically stored as “calibration” values that may be used to perform a least squares-based fitting between the torque values and current values of wheel position and torque. The adaptive algorithm then evaluates the torque model for the current time. The wheel position values are typically the “static” and “dynamic” values. Static values are stored in a look-up table (LUT) provided by the microprocessor, and thus, are typically pre-calibrated and stored at power up of the system. The calibration values for the wheel torque are typically determined from steering wheel position and vehicle speed values. The steering wheel position values are typically obtained from a steering input shaft angular sensor. The vehicle speed values are typically obtained from vehicle speed sensors provided as part of a vehicle sensor assembly. In EPS systems, it is desirable to provide a robust control unit which uses various input and output signals to identify a number of operating parameters used by the control unit. An exemplary control unit is described in U.S. Pat. No. 5,883,377, which is hereby incorporated by reference herein in its entirety. This reference describes a control unit including at least one microprocessor having a microprocessor module and at least one nonvolatile memory. The microprocessor module includes instructions for controlling the control unit and the at least one nonvolatile memory includes: a plurality of calibration parameters, a steering signal compensation means, a vehicle speed signal compensation means, a speed range correction means, a speed threshold means, a torque gain setting means, and at least one of a vehicle dynamic model, a torque dynamic model, a position model, a low frequency filter setting, an electronic steering resistance setting, and an electronic braking power setting. These calibration parameters are the results of system parameter identification with various vehicle and operating parameters. The vehicle dynamic model characterizes the relation between the sensed vehicle dynamic parameters (e.g., steering wheel angular velocity, acceleration and position, velocity, and jerk) and the steering input power (e.g., steering wheel rotation, and steering torque). The torque dynamic model characterizes the relation between the sensed torque (e.g., wheel torque and torque input power), the sensed vehicle speed and the steering input power. The position model characterizes the relation between the sensed position (e.g., wheel angle) and the steering input power. The electronic braking power setting and electronic steering resistance setting are used to estimate wheel and vehicle cornering force, respectively. The low frequency filter setting is used to remove signal quantization noise. The above-identified control unit is an example of a control unit in which it is desired to provide a robust control unit which uses various input and output signals to identify a number of operating parameters used by the control unit. However, even when using the above-identified control unit, there are still some disadvantages in using adaptive control algorithms in vehicle EPS systems. For example, in certain prior art EPS systems, adaptive control algorithms are implemented in the electric assist motor control unit in the form of software-based and/or firmware-based modules/programs. As is well known, software-based and/or firmware-based modules/programs can be relatively readily implemented by a microprocessor. However, for use in some modern EPS systems, such as those designed to utilize modular EPS packages, and the like, significant hardware redesign of the motor controller may be necessary, making the inclusion of a microprocessor-based adaptive control algorithm difficult. One particular problem is the fact that the microprocessor is typically not utilized to provide any of the signals for identifying operating parameters. Rather, the microprocessor is configured to typically transmit control signals to the various components of the electric assist motor controller. Accordingly, it would be desirable to provide an adaptive EPS system in which a control unit is operable to determine operational parameters based on various inputs and output signals. It would also be desirable to provide an adaptive EPS system in which a control unit is operable to determine operational parameters based on various inputs and output signals received from various sensors and actuators. It would also be desirable to provide a system in which a control unit is operable to determine operational parameters based on various inputs and output signals for at least one electric assist motor and at least one steering wheel sensor. It would further be desirable to provide a system in which a control unit is operable to determine operational parameters based on various inputs and output signals for at least one electric assist motor, at least one vehicle sensor, and at least one steering wheel sensor. It would be further desirable to provide a system in which a control unit is operable to determine operational parameters based on various inputs and output signals for at least one electric assist motor, at least one vehicle sensor, and at least one steering wheel sensor, where the control unit is configured to select one or more of the operational parameters based on which signals are received. It would also be desirable to provide an adaptive EPS system that is substantially not reliant on having a microprocessor to determine the values of various parameters. It would further be desirable to provide a control unit that includes adaptive control algorithms for at least one electric assist motor. It would also be desirable to provide a control unit that includes adaptive control algorithms for at least one electric assist motor that does not rely on a microprocessor. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.