One of the most efficient ways to connect a resistive sensor array is using columns and rows in a 2-D structure. The main problem in this implementation is crosstalk appearing due to non-idealities in the readout circuits. Crosstalk causes measurement errors which restrict the usable range in array size or resistive sensors values. This paper analyses the way in which these factors affect accuracy, setting out a new approach to eliminate or reduce their influence based on just an additional operational amplifier and some calibration resistors without a significant increase in readout time. The first method involves introducing an additional column in order to eliminate the combined effect of the output resistance buffers for row selection, offset voltages and bias current of the operational amplifier. In the second method, a row of resistors is added in order to reduce the effect of finite gains. Theoretical analysis has been performed and validated by simulation. Results show that an improvement in accuracy compared with other proposals in the literature is possible.

The typical layout in a piezoresistive tactile sensor arranges individual sensors to form an array with M rows and N columns. While this layout reduces the wiring involved, it does not allow the values of the sensor resistors to be measured individually due to the appearance of crosstalk caused by the nonidealities of the array reading circuits. In this paper, two reading methods that minimize errors resulting from this phenomenon are assessed by designing an electronic system for array reading, and the results are compared to those obtained using the traditional method, obviating the nonidealities of the reading circuit. The different models were compared by testing the system with an array of discrete resistors. The system was later connected to a tactile sensor with 8 × 7 taxels.

The most efficient way to carry out the reading of a set of resistive sensors is to organize them in an array form. This reduces the number of wires to the sum of the number of rows, M, and columns, N, and reading can be carried out using just M+N multiplexers and a single operational amplifier. The drawback in this procedure is the appearance of crosstalk (the influence of the resistance of some sensors on the measurements of others). Although different proposals have been presented in the literature to reduce this phenomenon, errors in determining the resistance values of each sensor still exist in all the proposals. This article presents a new method to determine these values, which considerably reduces errors without the need for any hardware other than the simplest reading circuits. The method consists of a very fast recursive convergence procedure. The results show that the new proposal outperforms other solutions in the first or second step.

The paper deals with speed control for autonomous mobile robots. First a trajectory planner attaches a speed component to the postures of a path by considering speed limitations introduced by the vehicle and by task specifications. In order to provide robustness during task execution in the real world, environment feedback is used to dynamically adjust the speed of the vehicle to the presence of unexpected obstacles, both static and mobile. This is accomplished by combining the planned speed profile with the outputs of two reactive controllers. The system has been successfully implemented within the control architecture of the RAM-2 mobile robot.

Corti"s Organ is an Electro-Mechanical transducer that allows the energy coupling between acoustical stimuli and auditory nerve. Although the structure and funtionality of this organ are complex, state of the art models have been currently developed and tested. Cochlea model presented in this paper is based on the theories of Bekesy and others and concerns on the behaviour of auditory system on frequency-place domain and mechanisms of lateral inhibition. At the same time, present state of technology will permit us developing a microsystem that reproduce this phenomena applied to hearing aid prosthesis. Corti"s Organ is composed of more than 20.000 cilia excited by mean of travelling waves. These waves produce relative pressures distributed along the cochlea, exciting an specific number of cilia in a local way. Nonlinear mechanisms of local adaptation to the intensity (external cilia cells) and lateral inhibition (internal cilia cells) allow the selection of very few elements excited. These transmit a very precise intensity and frequency information. These signals are the only ones coupled to the auditory nerve. Distribution of pressure waves matches a quasilogaritmic law due to Cochlea morphology. Microsystem presented in this paper takes Bark"s law as an approximation to this behaviour consisting on grouped arbitrary elements composed of a set of selective coupled exciters (bank of filters according to Patterson"s model).These sets apply the intensity adaptation principles and lateral inhibition. Elements excited during the process generate a bioelectric signal in the same way than cilia cell. A microelectronic solution is presented for the development of an implantable prosthesis device.