A self-powered active sensing system for use in a downhole drilling environment, comprising: a vibration sensor for measuring vibration of a drill string, the vibration sensor including: a housing shaped to extend circumferentially about the drill string thereby allowing the drill string to rotate within a central opening, wherein the housing includes: an internal wall within the housing shaped to define an annular cavity extending circumferentially through the housing , and a screen provided on a surface of the internal wall defining the annular cavity; a ring structure that is generally ring shaped, wherein the ring structure is mounted within the annular cavity and coaxial with the annular cavity, the ring structure including: a spherical bearing extending from an outer surface of the ring structure that faces the screen, wherein the spherical bearing is configured to contact the screen, and a plurality of springs supporting the ring structure within the annular cavity of the housing wherein the springs are configured to maintain the spherical bearing in contact with the screen and enable the spherical bearing to move across the screen in one or more directions as a function of vibration forces acting upon the housing ; and wherein the screen is configured to generate an analog electrical signal (analog vibration signal) as a function of the movement of the spherical bearing across the screen in one or more directions, and wherein the analog vibration signal is representative of a position of the spherical bearing on the screen and thereby representative of the vibration of the drill string. a vibration sensor for measuring vibration of a drill string, the vibration sensor including: a housing shaped to extend circumferentially about the drill string thereby allowing the drill string to rotate within a central opening, wherein the housing includes: an internal wall within the housing shaped to define an annular cavity extending circumferentially through the housing , and a screen provided on a surface of the internal wall defining the annular cavity; an internal wall within the housing shaped to define an annular cavity extending circumferentially through the housing , and a screen provided on a surface of the internal wall defining the annular cavity; a ring structure that is generally ring shaped, wherein the ring structure is mounted within the annular cavity and coaxial with the annular cavity, the ring structure including: a spherical bearing extending from an outer surface of the ring structure that faces the screen, wherein the spherical bearing is configured to contact the screen, and a plurality of springs supporting the ring structure within the annular cavity of the housing wherein the springs are configured to maintain the spherical bearing in contact with the screen and enable the spherical bearing to move across the screen in one or more directions as a function of vibration forces acting upon the housing ; and a spherical bearing extending from an outer surface of the ring structure that faces the screen, wherein the spherical bearing is configured to contact the screen, and a plurality of springs supporting the ring structure within the annular cavity of the housing wherein the springs are configured to maintain the spherical bearing in contact with the screen and enable the spherical bearing to move across the screen in one or more directions as a function of vibration forces acting upon the housing ; and wherein the screen is configured to generate an analog electrical signal (analog vibration signal) as a function of the movement of the spherical bearing across the screen in one or more directions, and wherein the analog vibration signal is representative of a position of the spherical bearing on the screen and thereby representative of the vibration of the drill string. <EOS>